Practical Fish keeping - October 2023

1 0 OCTOBER 2023 £5.99 9 770262 580336 > ADVICE How to get the most from your bright red barbs CHERRIES ON TOP TESTED: Fluval Plant Spectrum LED Could this be the best ever freshwater nano light? FISHING FOR JOBS Career opportunities in aquatics explained AMAZING FISH AND HOW TO KEEP THEM Paradise unlocked! PLANTING ON WOOD Making the most of epiphytes CICHLID STARS The joys of keeping Paratilapia Maximising yields from Macropodus Review ROADTRIP TO JUST FINNS

High-performance filtration and quiet operation BIOMASTER Discover more at www.oase.com The BioMaster external filter uses a combination of biological filtering with Hel-X and mechanical/biological cleaning with filter sponges to ensure healthy and clear aquarium water. The EasyClean pre-filter chamber allows you to clean the filter without having to dismantle everything. And an automatic shut-off and safety lock prevent water leaks. The complete set includes filter media, hoses, adapters, suction and discharge pipes and a water diffuser. The Thermo version comes complete with an adjustable heater meaning you don’t need to have a heater inside your aquarium. Available in sizes 250, 350, 600 and 850 - suitable for aquariums up to 850 litres. Primer EasyClean pre-filter Can be removed separately from the rest of the filter. No mess maintenance Locking features are integrated into the inlet / outlet connection. Easy to carry Robust carrying handle. Easy to open EasyClick opening mechanism. Heater integration capability Easily integrate an OASE HeatUp adjustable heater (not included).

WHAT’S INCLUDED? 6 Practical tips from the world of fishkeeping 6 Get inspired with aquascape ideas for beginners and advanced 6 The latest aquarium equipment reviewed 6 Entertaining expert guides to global fish species 6 Practical Fishkeeping Magazine guaranteed right to your door every month 6 Advice on tropical marine, freshwater, tropical, cold water tanks and more! 6 Receive exclusive articles, discounts and free gifts GET YOUR COPY TODAY www.practicalfishkeeping.co.uk/store/subscriptions/practical-fishkeeping The world’s leading fi shkeeping magazine for over 60 years SUBSCRIBE AND SAVE! SAVE UP TO 20% WHEN YOU SUBSCRIBE FOR THE YEAR

OCTOBER THE INDIAN GLOWLIGHT Just because something’s rare, doesn’t always mean it’s expensive. Here’s a tiny scarcity that’ll fill your heart without draining your bank account. IN A BARBY WORLD Could a little red river dweller from Sri Lanka be the sweetest fruit you’ll ever keep? WILL THE REAL CORYDORAS LATUS PLEASE STAND UP? One catfish became mythical, because all we know of it is based on a poor formal description. OH STARRY NIGHTS Madagascar might not be our first ‘go to’ when we think of cichlids, but there’s at least one species there that’ll put stars in your eyes. FADE TO BLACK While the paradise fish is often regarded as an example of aggression, it does have a darker coloured but lighter hearted cousin. Meet the beautiful black sheep of the family. THE BLUE SPOT BREEDER Gabor Horvath visits an aquarist with a unique breeding accomplishment—marine stingray in the home tank! FISHKEEPING ANSWERS This month our PFK experts look at boosting reds in aquarium plants, suitable tanks for paradise fish, disposing of old aquarium chemicals, caring for clams, nano light intensity, Pseudotropheus compatibility, Congo tetra tankmates, a unique bichir parasite, and much more! KNOW-HOW: GUIDE TO AQUARIUM JOBS Fishkeeping—you love it, live it, drink it. But could you be one of the 12,000 or so people in the UK who work it? 06 34 INSPIRATION 28 REGULARS SUBSCRIBE! SEE OUR SUBS OFFER FOR THE BEST DEALS. Check page 3 for details. 10 34 20 4 PRACTICAL FISHKEEPING 42 62 52

THINGS YOU WILL LEARN IN THIS ISSUE KNOW-HOW: EPIPHYTE PLANTS AT A GLANCE Not all of us can grow plants in substrate. But why worry? There are plenty that’ll grown on rocks or wood, too. ROADTRIP: JUST FINNS Nathan Hill takes a journey out to a growing store with an exciting future. READERS’ POLL 2023 It’s back for another year—your chance to vote for the stores who you deem the best! GEAR GUIDE This month we take a look at OASE’s LessStress Water Conditioner, as well as their ScaperLine Plant Boost Tablets, before getting hands on with the amazing Fluval Plant 3.0 Nano, a whole lot of light in a tiny package. NEXT MONTH Growing killifish from eggs, the search for fancy goldfish, tiny suckermouths and Schismatogobius. TAILPIECE Sometimes you can use a word your whole life and then one day wake up and it doesn’t make sense. Well, we certainly have one in fishkeeping. Welcome I TAKE such delight in the simplest of fi sh these days. I wonder if it’s because I raced through the ‘beginner’ species when I started that I now realise I should have given them more attention. This month I’ve been catching up with a species I’ve not kept in well over a decade—the cherry barb. And, frankly, I don’t think I’ve ever been so engrossed in watching a single tank before. Hopefully my feature on them (p.10) will encourage others to give them a try. They’re so worth it. Of course, we also have some special fi sh this month, and what could be more special than Daniel Konn-Vetterlein’s possible encounter with (the real) Corydoras latus? Plus, we welcome another new contributor this month, in the form of Matt Needham from uShaka Sea World, who recounts his experiences with Paratilapia (p.28). Or, if you prefer a more hands-on experience, why not take inspiration from Gabor Horvath’s breeding successes with Macropodus spechti (p.34). I know I will! Nathan Hill, Editor Stay in touch Follow us at www.facebook.com/PFKmag/ Email us at [email protected] Watch us on youtube.com/user/practicalfishkeeping ON THE COVER Cherry barb, Rohanella titeya. Photo by Frank Teigler 68 74 82 4How to attach your plants to wood and rocks. 62 2 The diff iculty in identifying the real Corydoras latus. 3What your career options are if you fancy working with fish. WWW.PRACTICALFISHKEEPING.CO.UK 5 58 77 68 80 1 What are the safest live-foods to feed?

TROPICAL Horadandia 6 PRACTICAL FISHKEEPING Just because something’s rare, doesn’t always mean it’s expensive. Here’s a tiny scarcity that’ll fill your heart without draining your bank account. WORDS: NATHAN HILL THE Indian

WWW.PRACTICALFISHKEEPING.CO.UK 7 GLOWLIGHT FROM INDIA, you say? Well, yes and no. While not as bright and punchy as its South American namesake, the Indian glowlight— the glowlight carplet to give its trade name—is a low fidelity delight in itself. So, what is it? Glowlight carplets, Horadandia brittani, are danionin cyprinids, related to such treats as Inlecypris, Sundadanio, Rasbora, Danio and many more. Horadandia is most closely related to Trigonostigma (the classic harlequin rasboras) and Raboroides. There are two species in the Horadandia genus—H. brittani and H. atukoralia—and to the naked eye it’s difficult to tell them apart. Indeed, for many years the two were considered the same species, and it wasn’t until 2013 that H. brittani was finally formally described. At the level of magnifying glasses and calipers, you’d be looking at differences in body depth (H. brittani is negligibly deeper-bodied) and eye diameter (H. brittani having negligibly smaller eyes). If you’re looking that closely, you can also take note of two other unique Horadandia features—neither species possess either barbels or a lateral line. Your best bet at distinguishing the two is to find the catch location. H. atukoralia, also called the green carplet, is endemic to Sri Lanka, while H. brittani is confined to the southern states of India, specifically Kerala, Tamil Nadu and Karnataka. Here, the glowlight carplet inhabits coastal floodplains, where it loves heavily vegetated (read ‘heavily weeded’) ponds, pools and rice paddies. As such, and given it’s ‘at a glance’ superficial similarities with the popular green neon rasbora, Microdevario kubotai, it definitely has a future as a filler for aquascapes. While not as colourful as the green neon, it carries similar hues that are striking under the right light. But that’s assuming you can find some to begin with. Why haven’t I seen any yet? Availability in the UK is largely reduced by retailers not taking the plunge and stocking them. At a maximum size of around 1.5-2cm, these are the sort of fish that will end up becoming snacks in most mainstream tanks—a single angelfish could hoover up a shoal in an afternoon. As you might imagine, consumer demand for such a miniscule prey species is low, and when these do appear in stores, they are usually snapped up by the hardcore tropical aficionado, squirrelled away for home breeding. That’s a shame, as for their size, these adorable fish are surprisingly bulletproof. Their tank needn’t be large (45cm long will suffice for a shoal) and their water chemistry needs pretty much reflect tapwater from all corners of the UK. Thriving in a pH anywhere from 5.5 up to 7.5, and happy with hardness levels from 2-16°dGH, they really are a ‘fire and forget’ kind of fish. Even temperature doesn’t seem to put them out, equally happy at 20°C as at 26°C. FRANK TEIGLER

8 PRACTICAL FISHKEEPING The only real requirement is for a decent sized shoal, for which they’ll reward you by swimming both actively and in tight clusters. On the few occasions I’ve seen them in stores they’ve been more than aff ordable (on my fi rst encounter, they were just £1.50 a pop, more recently around £2.50 a head), so a decent sized group isn’t going to break the bank. Plants are preferable, and they don’t care which. Those lucky aquarists who have kept and spawned them use the breeder’s classic of Java moss, allowed to run riot around the tank, but any bushy plant, and especially some fl oating vegetation, will be appreciated. The temptation is to keep them in something brightly lit, but these fi sh will spook and wash out under intense light. If your lights are dimmable, keep them running somewhere around the 50-75% mark, and if not then fl oating plants become more valuable as they’ll diff use the brightness a little. Even fi ltration is a breeze, as you’ll want to avoid anything with a notable fl ow. Ditch the internal canister fi lters and go old school with an air-driven foam fi lter. As for the other tank details, they’re pretty unfussed. Substrate? They FACTFILE GLOWLIGHT CARPLET 6Scientific name: Horadandia brittani 6Pronunciation: Hor-a-dan-dee-ah brit-an-ee 6Size: To 2cm 6Origin: Endemic to southern India 6Habitat: Pools, ponds, rice paddies, slow rivers 6Tank size: 45x30x30cm 6Water requirements: Soft and acidic to slightly alkaline water; 5.5-7.5pH, 2-16°H 6Temperature: 20-26°C 6Temperament: Peaceful species, but too small for many community tanks 6Feeding: Flakes, micropellets and small meaty foods like Cyclops 6Availability and cost: Hard to source but really inexpensive, prices from around £2.50 40 l+ Water volume don’t care. Leaf litter? Whatever, they say. Wood and rocks? They’re equally indiff erent, beyond their utility for providing some shade. Speaking of utility, glowlight carplets do make for fi ne dither fi sh. Being entirely uninterested in nipping or chasing tankmates, they lend themselves beautifully to shrimp and wild-type Betta tanks, bringing movement to what can otherwise be a notably docile layout. Food-wise, glowlight carplets aren’t fussy for anything beyond small morsels. Wild fi sh are micropredators that pick out tiny worms and crustaceans, but in aquaria they seem to do just fi ne on fl ake and micropellet foods, although the hunting instinct will defi nitely be ignited if a little Daphnia or Cyclops fi nds its way into their tank. More tiny carplets? A handful of UK hobbyists have bred them. A simple layout for egg scatterers (small tank, air driven fi lter, collecting tray of Jave moss over some rounded stones) is all it takes, along with a little conditioning with quality live foods beforehand. The eggs aren’t cared for by the parents, so need removing soon after spawning, and then you’ll need access to some cultures of fi ne foods like infusoria to add after around 48 hours, when the young start to hatch. These are tremendous little danionins that bring little trouble and a lot of pleasure. They make a great breeding project, a great dither fi sh, a great aquascaper’s shoaling display, or a superb little species-only project for the aquarist looking for something a little unusual. If you’re really interested then get involved in a local club—a little networking with the fi sh geeks will help you source some no time. FRANK TEIGLER TROPICAL Horadandia

INSPIRATION Cherry barbs 10 PRACTICAL FISHKEEPING Could a little red river dweller from Sri Lanka be the sweetest fruit you’ll ever keep? WORDS: NATHAN HILL

WWW.PRACTICALFISHKEEPING.CO.UK 11 ’VE OFTEN WONDERED if aquarium stores can sometimes create a false impression about how abundant fish are. Not deliberately, of course, and not by malicious intent. But by the sheer volume of fish they carry, the typical customer could go their whole life never knowing just how troubled some species are in the wild. The fish we see in stores are, by and large, the products of large farming and aquaculture operations, produced in their millions overseas and streamed to us as a ready supply. Alas, in many cases the wild counterparts may be living in dire straits. Some species we take for granted aren’t even found in the wild anymore. In step cherry barbs. They’re a community staple and a familiar face to any regular aquarium store visitor. Chances are that you may have even kept some before. So, it may come as a surprise that these seemingly ubiquitous fish are classed as ‘vulnerable’ in the wild. Endemic to southwestern Sri Lanka, they’re restricted to shrinking lowland rainforests, once vast and glorious but now broken up and divided across the land. After decades of British colonialism, civil war, and ever-encroaching industrialism had done its thing, some 95% of Sri Lanka’s tropical lowland rainforests had been destroyed. What remain for the cherry barbs are miniature oases, spread through the Kelani, Kalu, Gin and Nilwala basins. As with so many troubled species, there’s a strong chance that there are more in the hobby than there are roaming free. Meet the barb The gorgeous cherry barbs. Unless you’re up to date with the latest taxonomic trends, you’re likely to know them by the scientific name of Puntius titteya. If you’ve got older books to hand, you might even find them as Barbus titteya, or Capoeta titteya. Alas, all of these are outdated, and a recent taxonomic revision now places them in a new genus of their own, as Rohanella titteya. Across their range, there are notable variants. In the Kelani, Nilwala and Gin basins, there exists the ‘neon’ variant. The males of these FRANK TEIGLER A colourful cherry barb is hard to beat.

12 PRACTICAL FISHKEEPING the base of the caudal fi n. Meanwhile, you can also fi nd the ‘ruby’ variants in the Nilwani and Gin basins. These fi sh have a dark red dorsal edge, with paler fl anks and an absence of any horizontal stripe, the fi ns with a vivid pinkish-red hue. In all cases, the females remain paler, and with slightly less fl amboyant fi ns. It was suspected that the revision that created Rohanella would lead to these distinct populations being described as their own species or subspecies, but in the event the molecular data showed no diff erences between them. Same fi sh, diff erent markings. Lotic lifestyles Wild cherries roam in rivers and streams, typically of impeccable water quality, and containing either clear or only lightly-stained water. My friend and former PFK editor Jeremy Gay was privileged enough to once visit an actual Rohanella habitat, and is always quick to remind me that the shaded streams they call home are shallow— mere inches at best—with a mixture of cobbles and sand on their base. Whether they stay that way during the rainy season, when many rivers spate, is another story. Other reports from recent observers speak of dense leaf litter, especially at those locations chosen for spawning. The water they roam tends to be acidic up to neutral (around 6.3pH, but as varied as 5.0-7.1pH) and surprisingly warm. While many contemporary sources INSPIRATION Cherry barbs Scientists have managed to hybridise cherry barbs with checker barbs, Oliotius oligolepis. However, such hybrids would be worthless to the hobby, and shouldn’t be pursued. FACTFILE CHERRY BARB 6Scientific name: Rohanella titteya 6Pronunciation: Ro-han-ell-a tit-ay-ah 6Size: To 5cm 6Origin: Endemic to Sri Lanka 6Habitat: Shaded, slow moving streams over rocks, sand, and often deep leaf litter 6Tank size: 60x30x30cm 6Water requirements: Soft and acidic to neutral water; 5.0-7.0pH, 2-16°H 6Temperature: 22-28°C 6Temperament: Peaceful community species 6Feeding: Wholly unfussy, but off er some colour enhancing foods 6Availability and cost: A retailer staple, prices from around £2.50 54 l+ Water volume fi sh show a distinct boundary between the dorsal (upper) edge and the fl anks, the dorsal being brown with a yellow tint. Furthermore, they have an obvious horizontal line, starting at the tip of the snout, cleaving through the eyes, and running down until it nudges into Longfin cherry barbs are a line bred morph.

WWW.PRACTICALFISHKEEPING.CO.UK 13 cite temperatures of somewhere between 20-27°C for them, more recent expeditions report that 28-32°C is not uncommon (especially for spawning). In all habitats, very few (if any) aquatic plants are present, and the fi sh fl ock to areas that are shaded by overhead canopies. Domestic cherries How much of that natural habitat do we need to recreate in the home tank? Not a lot, it turns out. And while biotope aquaria are a great way to see wild-caught fi sh at their best, collection of Sri Lankan cherry barbs has long been prohibited. The cherries we see in stores have no idea what ‘wild’ even is anymore. Thankfully for us, these fi sh are brighter too, with years of selective breeding bringing out the best reds. In captivity, the domestic cherry barb is best described as unfussy. I’ve seen them as at home in gaudy fl uorescent tanks with multicoloured THE IMPORTANCE OF SUBSTRATE CLEANING My initial base layer of Kelkay horticultural silver sand is the finest sand I’ve used to date. By that, I don’t mean the best, but rather the smallest grain size. And it was filthy. Adding 5kg of sand to a large bucket, it took several flushes with cold running water until it was clean. But that’s nothing compared to the gravel. Dennerle Okavango gravel has to be the dirtiest substrate I’ve ever worked with. Claiming to have a ‘biofilm’ over it, it doesn’t come pre-washed. 5kg in a large bucket took over ten vigorous flushes before the water began to run off of it anything close to clean. Cleaning substrate is essential if you want to avoid cloudiness down the line. For a half hour of elbow grease early on, you’ll avoid days of waterchanges—not to mention the cursing you’ll do every time one of your fish decides to stir up the base of the tank. Clean in advance. Your water will appreciate it, your filter will appreciate it, and your enjoyment of the hobby will appreciate it. FRANK TEIGLER

14 PRACTICAL FISHKEEPING INSPIRATION Cherry barbs Soak your leaf litter well ahead of time, and keep changing the water it’s steeped in. This will allow you to add it to the tank later on without it causing as much staining. gravel as I have in heavily planted aquascapes. All they care about is good water quality, a stable environment, good food, and some space to spread their fi ns. So, a set-up is really easy, and any off the shelf kit from 60cm long will suffi ce. Filtration should be good but not excessive, with a decent internal canister leading the way. Ideally, you’re aiming to keep things slightly acidic to neutral (though I’ve seen many thriving in tanks at the 7.5pH mark), and somewhere soft-to-mid in hardness (4-15°H). Given their wide natural tolerance, I’d aim for a middling temperature of around 25°C, but beyond that the choice really is yours. Whatever you decide to design for them hardscape-wise, they’re pretty much sure to settle in it. For fi sh that come from habitats with few aquatic plants, they embrace greenery in the home tank with gusto. Mosses in particular seem to be cherished, but any plants will be explored and used as refuge for whenever they’re spooked. Not that spooking happens often, and you’ll soon fi nd your own cherries to be more curious than cautious. Shoaling is loose at best, with half-hearted aggregations forming amongst young fi sh that loosen up as they age. Which is great, visually speaking, as you end up with little fl ecks of red all over the tank. Displaying between males mainly consists of squaring up, side by side, with dorsal and anal fi n extended and some quivering. That may advance to circling each other, a little chasing, and that’s about as rough as it gets. For tankmates, anything that’s peaceful and has a similar water requirement will work—gouramis, dwarf cichlids, tetras, Corydoras… FRANK TEIGLER Up close, you can just see the tiny barbels. Caption, caption, caption.

WWW.PRACTICALFISHKEEPING.CO.UK 15 GETTING THE MOST FROM YOUR POTS Just because plants arrive in pots, doesn’t mean that they should stay in them. Sure, pots have advantages—they’re often established plants with good root structures, as opposed to the freshly cut sprigs that make up many bunched plants—but that doesn’t mean they’re the end game. For my tank, I ordered three pots each of two diff erent plants (Cryptocoryne wendtii ‘green’ and C. wendtii ‘tropica’), and on receipt I immediately dismantled them. Unless pot bound with roots, the rockwool holding the plants should easily pull from the pots, and can then be separated and the plants extracted. In some cases, you will need to tease rockwool away from the roots, and gently running water will help this. Each of my pots contained around six smaller Cryptocoryne which had any dying leaves removed, followed by the roots being trimmed back. Use sharp scissors for both of these jobs, and don’t be tempted to just tear at stems or roots (you’ll kill living tissue in the process, causing parts of the plant to rot in your tank). The prepared ‘plantlets’ were then inserted into substrate using a pair of narrow pinsettes, and are fed on a liquid fertiliser. And so, from an initial six pots, my tank now has around 36 young Cryptocoryne all establishing themselves! anything goes! I’ve never known a nippy cherry barb, and I’ve never known them to be intimidated by much (aside big fi sh) either. Feeding is equally straightforward. Wild fi sh like insects, diatoms and rotifers, but domestic ones will take anything from fl akes to frozen bloodworm. As long as it fi ts in the mouth, it’s fair game. Do try to include some vegetable matter, however, for colour purposes. For disease troubles, the only thing they appear especially sensitive towards is whitespot, Ichthyophthirius, and in my experience that’s only ever an issue with fi sh kept at the lower end of their temperature tolerance. Hardy, bright, and a deep red delight, there’s good reason these fi sh have become such a hobby staple. But there’s defi nitely no reason to take them for granted. If you’ve never kept them before, I implore you to try. If you have, I suggest that like me, you pick them up again for old times’ sake—they’re even nicer than you’ll remember. Now, let’s look at making a set up for them. FRANK TEIGLER Males become more intense in colour. Wild cherries roam in rivers and streams, typically of impeccable water quality, and containing either clear or only lightly-stained water

INSPIRATION Cherry barbs MAKING A CHERRY BARB HOME 1 2 Imagination, life is your creation. As we’ve established, the cherry barbs you’ll buy in store are not from the wild, so how much they’d appreciate a biotope is anyone’s guess. In fact, just having substrate and some décor will be a vast improvement on their time with the breeders and wholesalers who had them before you did. So, don’t overthink it. In this instance, I’m aiming at a loose approximation of what a Sri Lankan stream might look like, and I’ll let my imagination do the rest. Make a I’ve started with a base later of horticultural sand from Kelkay (purchased from a garden centre). The sand is washed prior to use and around 5kg is added in total, in a thin, consistent layer. Cobbles are added in a non-unform way across the sand. While it might be tempting to pile them high centrally or to one side, I’m keeping them mainly low, for reasons that will soon become clearer. 5 6 A couple of inches of water are added to the tank, and now I get into the gravel and sand with my hand, ruffling them into a mix. I keep playing until I reach the desired visual effect of an aged river. The tank is now filled to the top of the filter only, creating a shallower-than-usual display, and leaf litter and botanicals from Blackwater UK is added (alder cones, schima pods, oak leaves, pericarps, jacaranda pods, parviflora pods and Indian casuarina leaves). 16 PRACTICAL FISHKEEPING

WWW.PRACTICALFISHKEEPING.CO.UK 17 3 4 5kg of Dennerle’s Okavango 8-12mm aquarium gravel is washed (by far the dirtiest substrate I have ever had to clean) and added on top of the sand, with emphasis on making a slight bank to one side. An Eheim Biopower 160 internal canister filter and 55W heater are added to a rear corner where I’ve left a space for them in the cobbles. The filter and heater are set upright, but as low into the tank as possible. 7 8 A total of six plants (three Cryptocoryne wendtii ‘green’ and three C. wendtii ‘tropica’) are removed from their pots, separated, and spread around in the less decorated half of the layout. Pinsettes are used to position the plants. I’m in the privileged position of having an already mature filter to use, and so within hours of the tank reaching the required temperature, 18 cherry barbs are added at a ratio of two females per male, and the tank allowed to develop some algae. compromise with what looks natural, and what your own artistic tastes desire, and go from there. As long as you don’t add anything that alters the water chemistry, I’m sure the fish will be fine with it… As for size, I’ve opted to use my OASE ScaperLine 60 aquarium with a 60x35cm footprint. I could use a smaller tank, but don’t want to restrict myself on shoal size— this tank will happily hold 18 adult cherries. Cherry barb rivers have a moderate flow. SHUTTERSTOCK

18 PRACTICAL FISHKEEPING Can I breed them? Cherry barbs are easily bred—you might even see fry appear in a heavily planted community tank. To get the most of them, consider a separate breeding tank that’s soft (4-6°H), slightly acidic (6.5pH) and warm (27-28°C). Keep the base bare and add some healthy portions of Java moss around the bottom. Some breeders like to include a tub or bowl of marbles to help protect the scattered eggs, but I’ve never bothered. Condition up the adults ahead of time with plenty of live and frozen foods, and then select the plumpest female and move her across to the breeding tank one afternoon. That evening, add the most vibrant male to the breeding tank and leave them overnight. By the following morning, you’ll see the male (he’ll be redder than ever now) trying to lure the female down into the moss. Eventually she’ll join him, there’ll be some shuddering and then eggs and sperm will be released. They’ll keep this up for a few hours, after which you want to immediately remove them both back to their main tank so that they don’t eat the eggs they’ve laid. You’ll get around 200 eggs from a normal spawn. After 36-48 hours you should see some hatching activity, and around day three (after laying) you’ll see the fry to start moving around as they’ve exhausted their yolk sacs. At this stage, start adding infusoria to the tank, and as soon as they can accept it, start feeding them on fi nely powered fl ake foods (I always had better growth with dry food than I did with microworms or Artemia nauplii). It takes about 60 days before the fry have transitioned to junior, 1cm cherries, and around 150 days before they reach 2.5cm—assuming they’re getting enough food! Don’t expect to make a business from your cherry breeding exploits. While you may end up with lots of barbs (no bad thing), the competition is stiff —every respectable Far Eastern fi sh farm is churning the things out in their millions, so you might fi nd you spend more time rehoming your young than selling them. INSPIRATION Cherry barbs RAMP UP THE REDS The colour in cherry barbs is largely influenced by carotenoids—colour enhancing pigments produced by plants and algae. To keep your barbs at their absolute best, you want to feed a diet rich in them, which are typically advertised as ‘colour enhancing’ foods in stores. There’s more reason than colour to feed, too. As well as improving the immune systems of fish, research has found that the redder a cherry barb is, the better the quality of his sperm! Keep an eye out for the following: 6OASE Organix Colour Flakes — Packed with salmon, you can see the redness oozing from every flake. Great all-round diet. 6Bug Bites Colour Enhancing Flakes — Containing black soldier fly, these are snapped up by most fish. 6Hikari Vibra Bites — Shaped like little bloodworm, these can be great for tempting reluctant feeders. 6Tetra Pro Colour Multi-Crisps — Thicker than flakes, these are superb for adult barbs, though smaller fish may struggle with them. 6Cyclops — Frozen cyclops are a bright orange treat that smaller fish will love. 6Calanus — an absolute powerhouse of colour enhancing, frozen Calanus is my absolute go-to for boosting reds. Females are much lighter in colour. Cherries feed in the upper levels. SHUTTERSTOCK FRANK TEIGLER

www.practicalfi shkeeping.co.uk/store/reader-offers YOUR ULTIMATE GUIDE TO No matter your level of fi shkeeping ability, our masterclass is packed full of helpful information to keep your aquarium healthy and thriving. TEST YOURSELF AFTER EACH MODULE! 6 Water Chemistry and quality 6 Filtration and cycling 6 Habitats and physiology 6 Disease diagnosis and management 6 Husbandry and maintenance

20 PRACTICAL FISHKEEPING Daniel is president of the Association of Barbs, Loaches, Tetras, and Catfish. DANIEL KONNVETTERLEIN Intense green with a metallic sheen, rarely found in scientific collections and sought after by hobbyists—one catfish became mythical, because all we know of it is based on a poor formal description. TROPICAL Catfish ID Will the real Corydoras latus

WWW.PRACTICALFISHKEEPING.CO.UK 21 The 2012 catch and likely the real deal— Corydoras latus. ALL PHOTOS: DANIEL KONN-VETTERLEIN

22 PRACTICAL FISHKEEPING TROPICAL Catfish ID N AUGUST 2012 I was on top of the world. At the Río Ibare (inlet of the Río Mamoré in Bolivia) we managed to catch wonderfully green shining armoured catfish, which we later identified as Corydoras latus. This classification was also supported by our proximity to the fish’s known origins, as we were only 220km away from its type locality (the spot from where the first example of a species is caught). In the rainy season, the type locality and our capture locality are connected by numerous small rivers and a large intervening swamp- and lake-landscape. Such a range would not be unusual. However, since there were few live photographs of a true C. latus at the time for us to compare our fish with, some uncertainty remained. This uncertainty was amplified when the holotype of C. latus was examined and assigned to the C. elegans group, placing it in lineage 5. My captured specimen belonged to lineage 8, and so it seemed to be something else after all. Thus thwarted, finding the species ID slipped down my list of immediate priorities. We had been active several times in the vicinity of the type locality of C. latus, but apparently had never been successful. Now other regions of Bolivia were on my agenda, and so the latus myth lived on. Uncertain beginnings The ichthyologist Nathan Everett Pearson described Corydoras latus in 1924, based on a single specimen from either Lago Rogagua or its surroundings in Bolivia. The lake is located in the middle basin of the Río Beni. Pearson writes that the holotype measured 64mm in total length (TL), describing it in colour as: "body and fins uniformly blackish, body high, rather strongly compressed, a dark stripe along the meeting of the dorso- and ventrolateral lateral plates". This holotype suggests a large, highbacked and short-snouted species, and this is all we know about the character of the fish. The colour description should be taken with some caution, because the fish’s chromatophores had probably been destroyed by preservation. Fast forward to 1980 and ichthyologists Han Nijssen and Isaäc Isbrücker measured the holotype again, stating the standard length (SL) as 41.5mm. They assigned C. latus to the C. elegans group (now known as lineage 5). Joachim Knaack (in work from 2002 and 2004), on the other hand, stated that the anatomy of the pectoral spines of the holotype was close to the species group around C. reticulatus (C. geryi, C. pantanalensis, C. reticulatus and C. sodalis; today known as lineage 8) and that C. latus was much more closely related to them instead. He ruled out a closer relationship with the C. elegans group. Knaack also pointed out that the SL was much closer to 45mm. For the sake of completeness, it should also be mentioned that the SL is given as 52mm on Fishbase. In 2019 Allesandra Bono et al. examined, for the last time so far, pictures of the holotype in detail and placed C. latus, also on the basis of BELOW: Male Corydoras pantanalensis. TOP RIGHT: Female C. bilineatus. MIDDLE RIGHT: Female Corydoras pantanalensis. BOTTOM RIGHT: Male C. bilineatus.

WWW.PRACTICALFISHKEEPING.CO.UK 23 the dentition of the pectoral spines, in a closer relationship around lineage 5, confirming the prior work of Nijssen and Isbrücker. According to them, the position of the eye as well as the course of the frontals and the parieto-supraoccipitals (‘the forehead’) also lent weight to this assigning. For almost 100 years now, all of these assumptions and comparisons have been based exclusively on the holotype, pictures of it, or its description by Pearson. There are some fish in the ichthyological collection of the Naturalis (Leiden, Netherlands) deposited as C. latus—these have been used in work on the identification of other unknown individuals. But, in this case, they only add more confusion. For example, under catalogue number ZMA 119.861 is an armoured catfish classified as C. latus. Based on the available pictures, this fish can be assigned to lineage 8, while there are other specimens in the same collection that most probably belong to lineage 5. To make this picture complete, I need to add that there are other specimens in Leiden catalogued as C. latus, dating from 1966 (ZMA. PISC.111295, - 296, -297) and 1983 (ZMA.PISC.116751). The seven individuals from 1983 come from a collection of W. Staeck and are assigned to C. cf. aeneus according to Knaack (2002). In the collection of the Humboldt University (Berlin) there are also three specimens from 1991 catalogued as C. latus with ZMB 32.676, which, according to Knaack (2001), do not correspond to the holotype. According to him, these are possibly also C. cf. aeneus. C. latus is therefore very rare in collections, and the specimens deposited as such need to be examined. In the hobby By stark contrast, so-called Corydoras latus regularly appears in the trade, but it’s never really this catfish. Usually, the species name is used for a green-shimmering, voluminous Corydoras species, which is somewhat more high-backed. Such individuals afterwards reveal themselves as C. pantanalensis at the latest stages of the

24 PRACTICAL FISHKEEPING TROPICAL Catfish ID breeding season, when the typical reticulation of the males appears. In particular, females of lineage 8 correspond to the common idea of what a C. latus should look like. This probably goes back to German ichthyologist Werner Seuß, who in the 1990s depicted inconspicuous individuals (often females) of C. pantanalensis as C. latus, while referring to the prettier ones (often males) as C. bolivianus (today a synonym of C. geryi). In doing so, he followed the orthodoxy of the time, because according to Knaack, numerous C. pantanalensis and C. geryi were exported from Brazil under false names as early as 1989. The latter is also occasionally offered as C. latus, but when well cared for and given time to grow it quickly shows stripes in the caudal, which rules out any confusion. C. geryi is also somewhat more elongated and young fish in particular show a dark anteriorposterior dorsal stripe. For a long time, the species was, and still is, confused with C. bilineatus (lineage 5). If Bono et al, and Isbrücker and Nijssen are right, C. bilineatus probably looks very similar to the true C. latus—the black caudal spot and the green colouration are not untypical for this group. The changes in colour and pattern between the mating colouration and the normal state, as well as the different phenotypes of males and females of both lineages 5 and 8, and the lack of comparative material of C. latus make a reliable statement tricky. Ingo Schindler and Hans Evers for example, published a report in 2000 on a Corydoras species that was determined to be C. latus by comparison with the image of the holotype, as well as its description by Nijssen and Isbrücker. Even some of their individuals (ZMA 116.751) were determined as C. latus by the mentioned scientists. But shortly afterwards Knaack described Corydoras bilineatus, and the species treated by Schindler and Evers turned out to be just that. Interestingly, Knaack originally started describing C. bilineatus because he wanted to clarify whether the numerous specimens traded and labelled as ‘Corydoras latus’ really corresponded to this species. He examined pictures (at the least) of the holotype and came to the conclusion that it was a male that could not be assigned to the C. elegans group (lineage 5). He also stated that in 2001 the capture of the true C. latus was probably successful, but does not go any further on this point. Thus C. latus became an enigma again. To make matters worse, from 1993 another name become established in aquaristics: C. latus ‘San Juan’. But the images associated with this fish also show C. bilineatus. Another wellknown picture showing a catfish related to C. bilineatus, and often associated with C. latus, comes from the American breeder Frank Falcone. His very dark individual shows a black caudal spot running in a dark lateral line towards the front. This individual doubtless belongs in lineage 5. Hans Evers and Ian Fuller, in a 2005 work, presented an individual photographed by Knaack as C. latus, which is marked as a topotype (originating from the type locality) and was caught in the course of preparations for the formal Corydoras is currently the largest genus of Neotropical fishes, with at least 170 species registered on the database Fishbase, and many more still awaiting description.

WWW.PRACTICALFISHKEEPING.CO.UK 25 description of C. pantanalensis. This individual can be assigned to lineage 8 and resembles C. pantanalensis. The fact that it is referred to as C. latus by Knaack, who described C. pantanalensis himself (Knaack, 2001), strongly suggests that it might not be this, but perhaps a yet undescribed species of lineage 8. Knaack’s description of C. pantanalensis mentions a difference to C. latus—mainly the distribution of the two species, but doesn’t raise any morphological differences (due to the lack of material of C. latus). Should Knaack be right, and if Evers’ and Fuller’s depiction of C. latus (being lineage 8) is correct, then we would very likely have caught the real C. latus in Río Ibare in 2012. But, according to the current state of science, we caught something else. Expect the unexpected Ten years after this possible capture success, I was on the expedition ‘CuFundulus2022’ which set out to map killifishes in Bolivia. In addition to our target species, we also succeeded in catching some beautifully green-shimmering armoured catfish, most of them belonging to the Corydoras aeneus complex. But some fish in the net were already recognisable as something else, and we were quick to pick these anomalies out. In the photo tank they were more compact, highbacked and a dark caudal spot was clearly visible—the classic identifying feature of the C. elegans group. At the time, firmly believing that C. latus belonged to lineage 5, we seemed to have been successful. Unexpectedly, we had apparently caught this long-sought catfish species, but for the time being we referred to our individuals as Corydoras sp. ‘1’. Our journey took place in eastern Bolivia. About 900 km southeast of the type locality of C. latus, we had come across a site in the basin of the Río Otuquis where we encountered four syntoptic Corydoras species together: C. aff. aeneus, C. geryi, C. polystictus and C. sp. ‘1’. It seemed that C. polystictus formed the main group, while the other three species mingled with them. The second most common species we caught was C. aff. aeneus, while C. geryi and C. sp. 1 we only found as single specimens. TOP: The Rio Otuquis looks healthy now, but deforestation creeps closer. ABOVE: One of Daniel’s Coryrich catching sites. LEFT: Corydoras geryi from Rio Ibare.

26 PRACTICAL FISHKEEPING TROPICAL Catfish ID Regarding the biotope of this site, the bottom was sandy but covered with lots of fallen leaves. The current was weak and the water clear though brownish in colour, and visibility was low. The Corydoras were mainly found in the shallow regions and only infrequently caught any deeper than 40cm down. We also managed to find C. sp. ‘1’ at another site, 200 km further west, alongside an undescribed Brochis species. This time the biotope was only the residual water left by a river flowing a few metres away. The water temperature was 33°C, and the water was loamy brown. The pond was probably only a few days away from drying up completely. Putting an end to the myth A month after the CuFundulus2022 trip, when we showed a few pictures at the Catfish Study Group Convention (England), our fish were also determined to be C. latus. It could hardly have been better. However, as time went by, the specimens that we were keeping in tanks became more and more discoloured and finally resembled an old acquaintance: C. bilineatus. But that alone did not mean anything; remember, according to Bono et al., both belong to lineage 5. And so, it came down to a new comparison using the scantly available material or pictures. However, no females are known from lineage 5 so far that would have reached the size of the holotype. In addition, Hans Evers pointed out the differences in the arrangement of the bone plates, which stand out when comparing the holotype with, for example, C. bilineatus, and which, like the high-backed and rhomboid shape of the holotype, suggest that C. latus does belong to lineage 8 and does not come from any relationship around C. elegans. This would also correctly identify the abovementioned specimen deposited as ZMA 119.861, as well as the topoytpe presented by Evers and Fuller. Using live pictures, the two groups cannot be confused, and after some uncertainties, we can now say with a high degree of probability that we did, in fact, catch the real C. latus in 2012, as Knaack did 11 years earlier. Catch site of many of the fish seen here. C. sp ‘1’, now referred to as C. cf. bilineatus. C. aff. aeneus from Rio Otuquis. C. polystictus. Juvenile C. geryi.

WHAT ARE THE LINEAGES? As a recap, the Corydoradinae are currently broken up into 9 distinct lineages based on various taxonomic characteristics. While the exact classifications are still to be agreed upon, it looks as though they will end up as: Lineage 1 — Corydoras Lineage 2 — Aspidoras Lineage 3 — Scleromystax Lineage 4 — Microcorydoras Lineage 5 — Gastrodermus Lineage 6 — Unknown (no previous genera existed for this lineage) Lineage 7 — Osteogaster Lineage 8 — Brochis Lineage 9 — Hoplisoma WWW.PRACTICALFISHKEEPING.CO.UK 27 C. sp. ‘1’ after settling in to an aquarium.

28 PRACTICAL FISHKEEPING Madagascar might not be our first ‘go to’ when we think of cichlids, but there’s at least one species there that’ll put stars in your eyes. TROPICAL Paratilapia

WWW.PRACTICALFISHKEEPING.CO.UK 29 Senior aquarist at uShaka Sea World and editor of The Fishkeeper magazine. MATT NEEDHAM Adult male sporting his nuchal hump. SHUTTERSTOCK

30 PRACTICAL FISHKEEPING TROPICAL Paratilapia N MY YOUNGER years, I was forever a keen enthusiast of browsing every fish store I could, gazing upon the magnificent specimens I found. The fishkeeping hobby had really bitten me hard at an early age. Unfortunately for us South African aquarists, we never had many true aquarium stores dedicated to the hobby through the 90s and early 2000s. Instead, our general pet stores and hardware stores were usually the places where we could stumble upon a few aquaria. Fortunately, this has changed over the last couple of decades. It was within one of these stores in the late 90’s that one fish really caught my eye. Jet black, and with iridescent spots scattered across its flanks and fins, my jaw dropped at the sheer beauty of it. Upon enquiring, the shop assistant informed me that it went by the name of starry night cichlid, a name that could not have been more suited. There and then I promised myself that I would one day not only keep this gem, but reproduce it too. Over the following years I never once came across any within a dealer’s tanks and had lost all hope of sourcing one. It wasn’t until 20 years later in 2019 that finally I came across a post on a local Facebook page from a hobbyist who had bought a group and was selling a few off. In an instant, I was on the phone and headed off and purchased two individuals that appeared to have separated themselves from the rest of the group. I’d fulfilled half of my promise. Trouble at home Starry night cichlids also go by the names of black diamond cichlid or polleni—the latter being the most common on livestock lists, and the specific epithet of the scientific name: Paratiliapia polleni. Polleni are endemic to the island of Madagascar. They were once widespread throughout the country, but unfortunately are far less common now due to activities that have had a drastic impact on their natural environment. Activities such as overfishing, habitat degradation, introduction of non-indigenous species, farming, and so forth, have virtually destroyed many of the habitats where not only this species is found, but a multitude of others. Whilst they’re listed by the IUCN Red List of Species as ‘Vulnerable’, the work carried out by some intrepid aquarists meant that this species could be kept alive in captivity, with it now widely available in the hobby. Unfortunately, research on the cichlids of Madagascar pales in comparison to those found in the Americas and Central and Western Africa. Hopefully this will change as an interest keeps growing in these old-world cichlids. Habitat and behaviour Throughout Madagascar, polleni can be found within a variety of different habitats in the wild, from altitudes greater than 1km and temperatures reaching down to 12°C, to hot springs with temperatures reaching as high as 40°C—and even brackish ALAMY Juveniles can appear bland. That large mouth is for eating fish.

As polleni are largely active at night in the wild, try getting into the habit of feeding them after you have turned the aquarium lights off. water environments. The fact that these fish can exist within such a variety of conditions, from acidic, to alkaline and brackish, makes this species potentially one of the hardiest cichlid species available to the aquarist. Establishing themselves The two fish I had purchased didn’t look particularly different from each other at 6-7cm long, and they were given a 100-litre aquarium of 90x40x30cm. This proved ample for the pair as they grew although I would recommend something in the region of 120x45x40cm/200 litres, as the males have the potential to reach 28cm long. Females are known to stay considerably smaller than the males though, maxing out around 15-18cm. Sexing my pair wasn’t challenging at all. Once the male had reached the 10cm mark and the female 8cm, the male developed longer extensions to his dorsal and anal fins whilst the females remained rounded in shape. The male also began to develop a nuchal bump as he matured although this was small in comparison to what is seen with species such as Cyphotilapia frontosa. As with the majority of the large cichlid species, it’s good practice to purchase a group of at least six juveniles. This is done to allow a compatible pair to develop from the group. It’s rare that you’ll be as lucky as I was and be able to purchase two individuals that had already chosen to break away from the others in the seller’s aquarium. Once paired, they’re known to become quite peaceful with each other—most male/female aggression occurs between juveniles in the pairing up process, and I found this to be the case with my pair. They got on well together, with few arguments occurring between the two. Just note that no other males will be tolerated in the same tank as a bonded pair. The aquarium was set up with a fair amount of cover in the form of clay pots, large round stones and driftwood. I’ve found polleni to be quite shy when initially introduced, becoming more confident in their settings over time. Plants can be added as they don’t tend to pay much attention to them. It’s possible to house this species within a cichlid community aquarium, although you should select species of a similar size and behaviour— NEIL HEPWORTH FRANK TEIGLER ALAMY One of many Paratilapia habitats. The spots maketh the fish!

TROPICAL Paratilapia polleni do not appreciate being bullied by overly aggressive species. Some of the other cichlid species from Madagascar, such as the Paretroplus make great companions, along with Madagascan rainbowfi sh, which help fi ll the mid- to upperlevels of the tank. As mentioned earlier, polleni are found in a variety of temperatures in the wild and will be quite happy between 22-28°C within the aquarium. My heater was set to 26°C, at which I found mine to be the happiest, whilst the pH was 7.2 and total dissolved solids 100ppm. A 25% water change was conducted weekly and during times of spawning this was reduced to 30% fortnightly. There’s been a bit of talk within the fi sh keeping community that they tend to be a little susceptible to white spot at cooler temperatures, a disease that they don’t cope well with. Due to polleni being rather large as well as extremely messy feeders, strong fi ltration is essential. A good-sized external fi lter is always recommended with plenty of mechanical media (sponges) to pull out any detritus. Surface agitation is a must, as these fi sh thrive in high oxygen levels. In the wild polleni are considered primarily piscivores although in the aquarium this is less pressing. I did fi nd that my pair, especially the male, were quite hesitant to eat in the fi rst few weeks, but eventually the addition of some feeder guppies prompted them into eating readily. (Ed’s note: Check the legislation in your native country before considering any live foods, as this may be illegal in some areas.) Once feeding, they took to a variety of quality large cichlid pellets. Frozen foods were also off ered on the odd occasion and relished. The important thing is to not off er any terrestrial meat, as their digestive tract is not designed for it and may lead to major intestinal issues. As polleni have been known to live for 10 to 15 years in captivity, they’re a worthy investment that’ll bring you many years of pleasure. FACTFILE POLLENI 6Scientific name: Paratilapia polleni 6Pronunciation: Pa-ra-til-ap-ee-ah poll-en-ee 6Size: Males to 28cm, females around 14cm 6Origin: Endemic to Madagascar 6Habitat: Rivers, streams, pools, even in brackish water 6Tank size: 120x45x40cm 6Water requirements: Aim for something around neutral; 6.5-7.5pH, 4-16°H 6Temperature: 22-28°C 6Temperament: Will eat small fish and may fight with some other cichlids 6Feeding: Appreciates meaty foods as well as slow sinking pellets, think Mysis, krill, prawn, mussel and so on 6Availability and cost: Not the most common cichlid put there but it crops up when a retailer gets curious, prices from around £12.50 200 l+ Water volume 32 PRACTICAL FISHKEEPING

WWW.PRACTICALFISHKEEPING.CO.UK 33 FOUR OR MORE? There is still a lot of debate within the genus of Paratilapia as to how many species there are and if any are separate. It is currently believed that there are four different species that exist within the hobby. Paratilapia sp ‘Andapa’ is thought to possibly be Paratilapia typus. Paratilapia sp ‘East coast small spots’ is the species believed to be the most common in the hobby and what we currently call Paratilapia polleni. The other two are Paratilapia sp ‘Fianarantsoa green’, and Paratilapia bleekeri—the largespotted form which is thought to be very rare. Work still needs to be done on the genus of Paratilapia, but I foresee a possible breakdown of several species in the future. Fulfilling the second promise The pair I acquired started to show interest in spawning just a few weeks after being added to the new home. Even though there were abundant displays and sexual cues, it was only once the male and female reached 10cm and 8cm respectively that they finally produced their first batch of eggs. Paratilapia polleni are identified as bi-parental substrate spawners. The eggs do not adhere to a surface such as a rock, but instead are laid as a gelatinous pinkish mass which rests at the base of the spawning site. In my experience, this tends to be within excavated pits in the substrate, the bases of clay pots, or within them—there never appeared to be a preferred spawning site. As with all cichlid species, the pair was energetic in the care of both their eggs and their fry, defending the spawn and vigorously rushing the front glass of the tank as I approached, or chasing off my encroaching hand. The male developed a rich black colour during this period, with light spangles across his body and fins. It has been recorded that up to 1000 eggs may be laid depending on the size of the female but I’ve never experienced more that 200-300 at a time, even with the female at 10-11cm in length. These typically took around two days to hatch, with the young staying within the spawning site until they became free swimming six or seven days later. At this point they fed straight on newly hatched artemia. It's worth noting that a pattern began to emerge, whereby the pair only put there effort into rearing one out of every three of their spawns. Those raised fry were able to stay with the pair for up to a month and grew to around 1cm in length before parental care was finally aborted. Spawning is not unusual for an established pair although this species has been labelled as slightly more difficult to breed then your more common South and Central American cichlids. Even so, the rewards justify the effort! Bonded pairs are hard to source. Different lighting can bring different marking intensity. ALAMY FRANK TEIGLER

34 PRACTICAL FISHKEEPING BREEDING Black paradise fish A pair of M. spechti merge beneath a nest.

Prolific breeder and aquarist Gabor has an enviable, eco-friendly fish house in Wales. GABOR While the paradise fish is often regarded as an example of HORVATH aggression, it does have a darker coloured but lighter hearted cousin. Meet the beautiful black sheep of the family. Caption, caption caption ALL: GABOR HORBATH WWW.PRACTICALFISHKEEPING.CO.UK 35

36 PRACTICAL FISHKEEPING BREEDING Black paradise fish HE PARADISE FISH, Macropodus opercularis, was one of the first ornamental fish species ever imported to be kept in home aquaria. In the 150 years since its initial introduction, it has been a divisive fish; much loved and hated, praised and cursed, worshipped and neglected. While magnificent on the eye, it also has a reputation of being evil incarnate, terrorising and destroying tankmates. The problem here is generalisation. Akin to many dog breeds, paradise fish aggression varies considerably by individuals and also depends on other circumstances. But it’s never a given—I have kept several specimens and only very few of them turned out to be monsters. Given enough room and the right companions they behave well. They still have an attitude but it only adds to the fun of keeping them. I’ve been a long-time fan of paradise fish, in part because I love their body shape with the elongated free-flowing fins, but also the sparkling colours they display when courting or posing. You can find them to this day in many a shop (be sure to check the coldwater/ temperate sections) and they come in many different variants, from green to red or even albino. But, what if you like the shape but want an unusual colour? Then a close relative, the black paradise fish, Macropodus spechti, could be the solution. Paradise known Those familiar with the genus know that there are currently nine Macropodus species recorded, but you need to search high and low if you want to find any of them in a shop, apart from M. opercularis. Out of the rest M. spechti, M. erythropterus and M. ocellatus are sporadically available in the trade but the best way to source them is to find a breeder; at least this is how I managed to get my fish. To tell the truth I didn’t plan to buy a black paradise fish. I was originally searching for a brown spiketail paradise fish, Pseudosphromenus dayi, but the breeder didn’t have any available (if you know of some for sale, please contact me). But he had M. spechti on his list, and as I have always liked this fish (some of you may know it under its former moniker—M. concolor) I decided to order two pairs. While waiting for their arrival I did a quick background check on the fish to see how it compares to M. opercularis in terms of demands and behaviour. As you could expect from a Macropodus, the black paradise fish lives in a wide range of aquatic

WWW.PRACTICALFISHKEEPING.CO.UK 37 habitats, from hill streams to marshes, irrigation ditches to rice paddies. Being an anabantoid they must access atmospheric oxygen to supplement the intake via their gills, something that enables them to survive in areas other fish would suffocate. Black paradise fish can adapt to a wide range of temperatures too, but as they originate from Vietnam the lowest end of the range is around 20°C, as opposed to the cooler, mid-teens of the M. opercularis. Although there are accounts of M. spechti surviving at much lower temperatures, they are still tropical so do not keep them in unheated tanks in the long term, and especially not in colder rooms. Their varied natural habitats means that they’re not overly demanding regarding water hardness, anything under 22°dGH would suffice. As they need around neutral pH (6.0-8.0), regular tapwater can be used in their tanks (after treating it properly). The black paradise fish is considered to be less aggressive than its M. opercularis relative so could potentially be kept in a community setting with the right tankmates. Avoid much smaller fish and similarly-shaped species, but otherwise you can house them with a range of other fishes. If kept as a pair they’ll need some room. Adult males can reach over 7.5cm in length, therefore a sizeable tank—minimum 60cm—is needed. Decoration-wise you could use whatever you have available: a thin layer of sand, and pieces of driftwood with some plants (Anubias, Java fern) attached are perfect. It’s advisable to add some floating plants (duckweed or Pistia) as they could provide shade and also a potential foundation for building a bubblenest. ABOVE: Fry are dwarfed even by Artemia nauplii. LEFT: Building a bubblenest.

38 PRACTICAL FISHKEEPING FACTFILE BLACK PARADISE FISH 6Scientific name:Macropodus spechti 6Pronunciation: Mac-row-poe-duss speck-tee 6Size: To maybe 8cm 6Origin: Endemic to Vietnam 6Habitat: Versatile, found in anything from pools and ditches to backwaters and hillstreams 6Tank size: 60x30x30cm 6Water requirements: Not too far either side of neutral water; 6.0-8.0pH, 2-22°H 6Temperature: 20-30°C 6Temperament: Peaceful outside of breeding and nesting 6Feeding: Wholly unfussy, off er flakes, pellets, live and frozen Daphnia, bloodworm 6Availability and cost: Not often carried by retailers but often available to order in, prices from around £6.50 54 l+ Water volume BREEDING Black paradise fish

WWW.PRACTICALFISHKEEPING.CO.UK 39 For filtration an air driven sponge filter is more than enough, but an internal power filter would also work, just ensure there aren’t any strong currents as your fish won’t like them. Feeding them is a doddle, as they’re totally unfussy, accepting anything on offer. In the wild they mainly feed on insect larvae and aquatic worms, and in the home setting the inclusion of bloodworm and tubifex in their diet will be greatly appreciated. Feed them sparingly as they love eating and can easily become obese. Overweight fish will have a shorter lifespan and can face difficulties when breeding. An eye to spawn Based on my research I prepared a separate tank for one of the pairs (with intent to breed) and planned to house the other pair with one of my Betta dennisyongi group. On the expected day of arrival, I received a message from the seller that he couldn’t find one of the males so This fish is sometimes confused with M. erythropterus, though that fish has distinctly red dorsal, caudal and anal fins. only sent me a pair and a solo female. Despite the refund for the missing male I still wasn’t very happy as the high postage costs now were spread over fewer fish. When the fish arrived the next day, there was a young pair and an absolutely huge female in the box, almost twice the size of the male. I put the two smaller fish into the breeding tank and the lonely female in my community tank. I kept an eye on her to see if there was any animosity between her and the resident Betta but after a brief initial stand-off (where the dominant Betta male investigated the newcomer with a threatening pose) they all calmed down, and lived happily ever after. The breeding setup was as I suggested above; sand, some Anubias and floating duckweed, but I also added a small piece of polystyrene to the quietest corner of the tank to facilitate bubblenesting. This was kept neatly in its place by some overhanging roots of devil’s ivy, Epipremnum aureum, a great nitratemunching terrestrial plant I use in almost every tank. The couple settled down quickly and accepted food within hours of their arrival. Initially there wasn’t much interaction between them, they simply co-existed. As opposed to many anabantoids, the male didn’t show any aggression towards the female, but after a week or so the female began pestering him. She approached the male with clamped fins and turned slowly on her side, displaying her plump belly, showing her readiness to spawn. Seeing this activity, I raised the temperature to 25°C to induce spawning. OPPOSITE: Caption, caption, caption. BELOW: Surprisingly peaceful Macropodus.

40 PRACTICAL FISHKEEPING Nesting time My temperature increase had the desired effect as the next day I found the male under the polystyrene, blowing bubbles. His progress was slowed down by the frequent visits of the female checking out the state of the construction and offering herself for an embrace. Initially the male chased her away with flaring gills and fully stretched fins, but he wasn’t anywhere near as violent as Betta splendens males. After an hour he gave up and allowed the female to stay nearby and watch the building process. This resulted in even more disruption and more frequent mutual fin stretching displays. Although the bubblenest wasn’t ready they began courting with some practice embraces. I suppose it was the male’s first attempt at spawning as he couldn’t work out how to orient himself into the right position for a while. During their trials they managed to destroy his weakly constructed bubblenest, so by the time they actually managed to lay eggs no bubbles remained to hold them. A couple of hours later I saw a few eggs floating underneath the polystyrene but they all disappeared by the following morning. Although I knew that the first attempts by inexperienced bubblenest-makers often ended up like this I was a bit disappointed. I thought that I’d have to wait at least a month BREEDING Black paradise fish for the next opportunity but luckily I was wrong. Two days later the male built a new, sturdier looking bubblenest and the female showed renewed interest. Only five days after their unsuccessful initial effort, I found the pair embracing again. This time the male was more skilful and managed to hold the female for a longer period, allowing more eggs to be released and fertilised. It’s interesting to see that like many Betta, M. spechti males also get ‘cramps’, staying locked in a bent position even after the female slides out from the embrace. Because the eggs contain oils they don’t sink to the bottom, and so the buoyant eggs were collected orally by the male (occasionally the female helped out with this, too) and spat into the sticky bubblenest. Between embraces the male took time to repair the nest, so it didn’t fall apart. By the end of the courtship there were over hundred eggs neatly positioned among the bubbles. After spawning, the male guarded these eggs and the hatching fry, while the female left him alone. The eggs hatched after around 48 hours and the larvae just hung under the bubblenest for another two days, only becoming free swimming on the fifth day after spawning. My male proved to be a good father, diligently retrieving any wandering offspring by collecting them in his mouth and blowing them back to the nest. As the father gradually becomes tired of the increasingly impossible task of policing their roaming young, it’s best to remove the male at the end of the fifth day. ALAMY The name Macropodus is a reference to the long pelvic fins—macro meaning large, and podus meaning foot. ABOVE: Adults will gather up young to return to the nest. BELOW: Outside of spawning, M. spechti can be a little pale.

WWW.PRACTICALFISHKEEPING.CO.UK 41 Although there was a chance that some of the fry could survive among the floating plants, I wanted to raise a bigger batch, so I moved the pair to another tank. The fry were tiny, and even newly hatched brineshrimp looked gigantic next to them. You need the tiniest food to start them off—this is when an infusoria culture comes into its own, although finely powdered floating foods (like Sera Micron Nature) can also be used. Sinking foods are useless as the fry remain near to the water’s surface for the first fortnight. As such, some uneaten meals get past them and so to deal with the surplus food I added a small group of month-old Corydoras napoensis fry to the tank. At the end of the first week, I introduced microworms to the menu and by the end of the second week they were able to consume Artemia nauplii. From that point on feeding them was an easy task, as every type of food, including powdered granules and flakes, was readily accepted. Despite the frequent and copious feeding some of the fry grew much slower than others, though this phenomenon of uneven growth is not unusual among anabantoids. When they became six weeks old the largest individuals were three times bigger than the smallest ones, but as I didn’t observe any hostility among them, I kept the lot together. Raising the fry is easy, but you need an aquarium with a tight-fitting lid to ensure that the air layer above the water’s surface is war. This is especially the case if the tank’s kept in a cooler room as the cold air can cause problems when the airbreathing labyrinth organs of the fry are developing. If they catch a cold the juveniles become ‘belly sliders’, unable to swim midwater continuously. This is unfortunately uncurable. But once they pass this critical initial phase the offspring are quite hardy and should grow into healthy adults. If you want to search for a black paradise fish in stores, don’t look for the dazzling fish you can see on my pictures. When not courting or posing, Macropodus spechti looks somewhat inconspicuous: a beigelight brown body with a hint of red on the pelvic fin. In fact, there’s not much at all to suggest the great transformation they can go through when they become excited. The bodies of sparring males turn especially dark, almost black—hence the moniker. With the dark lace pattern on their heads, sparkling deep blue sides, and iridescent long trailing fins, M. spechti males presents a spectacle you’ll definitely want to observe in person. ABOVE: Fry are surface huggers. BELOW: The spawning embrace.

The Question of the Month gets a Tetra goodie box! ADVICE I have an unheated 60 l cube aquarium, heavily planted and with an air-powered sponge filter. I was going to add a fighter as the sole fish, but the plants have been doing very well without a heater, so I wondered about adding a paradise fish instead. Is the tank big enough, and would it be happy on its own? If not, do you have any other suggestions? I want to keep a fish with a bit of ‘personality’ and having a more surface/midwater resident means the aqua soil won't get disturbed so much. The room is heated in winter. CAROL STEVENSON BOB REPLIES: The paradise fish, Macropodus opercularis, is a somewhat overlooked aquarium classic and while a little larger than the Betta, a single specimen should be okay in your tank. Females are a little smaller than males so might be a better fit for your tank, which is at the bottom limit of what I’d recommend in terms of volume. Although they are not as flamboyantly coloured and lack the extravagant fin extensions of males, they are no less characterful. Like the fighter, these are air-breathing ‘labyrinth’ fish, so make sure they have access to the water surface. Will this tank suit a paradise fi sh? Paradise fish are often overlooked. SHUTTERSTOCK Got a fishkeeping question? PFK’s crack team of aquatics experts are on hand to answer whatever you need to know... [email protected] Peter is our disease expert. Send questions his way if you have pathogen problems. DR PETER BURGESS THE EXPERTS Bob is a master of fishkeeping general knowledge and community tanks. BOB MEHEN Jeremy is more than adept when it comes to cichlids, goldfish and marine species. JEREMY GAY Aquascaping prodigy Jordan is the man to go to for all your planting issues. JORDAN STIRRAT Max is like a living, breathing search engine. Cichlids are his speciality. MAX PEDLEY Neale is the man for your technical queries. He loves brackish fish, too. NEALE MONKS Dave is a consultant for the Tetra Advisory Board and a research fellow at Keele University. DAVE HULSE Send your questions to: Fishkeeping Answers, Practical Fishkeeping Magazine, Warners Publishing, The Maltings, West Street, Bourne, PE10 9PH. Email us at [email protected] 42 EVERYTHING YOU NEED FOR HEALTHY FISH TEMPERATE

JORDAN STIRRAT JORDAN STIRRAT JORDAN STIRRAT SCAN ME FOR EXPERT AQUARIUM CARE AND ADVICE 43 I’ve tried several species of red plants including Ludwigia arcuata and Rotala rotundifolia, but at best they just turn a pinkish-orange colour at the tips. I don't have trouble with other stem plants and fertilise regularly. Please can you advise? ROB COUZENS JORDAN SAYS: Red plants exhibit a range of colour variations, some boasting a deep crimson hue while others bear only a faint tinge of red. However, the belief held by many hobbyists that a single factor can unlock the vibrant colours they crave is mistaken. One common misconception is that elevating iron levels will lead to red coloration, but while iron is crucial for overall plant health and pigmentation, excessive dosing does not help. Most commercially available all-in-one fertilisers already contain a suff icient amount of iron, which is actually a small amount. It's important to note that diff erent red plant species react diff erently to various conditions. Nonetheless, supplying plants with a comprehensive array of nutrients is a solid foundation to build upon. Basic aspects are frequently overlooked, including regular fertilisation, ensuring adequate CO2 levels, and upholding consistent maintenance. While not applicable to all plant species, most vibrant plants require CO2 injection to display their optimum colours. For most plant varieties, maintaining a CO2 level of around 30ppm is optimal. The puzzle is incomplete without considering nitrate limitation, especially for species like Ludwigia arcuata and Rotala rotundifolia. However, this might not be desirable for all plants. In fact, this approach could hinder the growth of certain plants if nitrogen levels plummet too low. Therefore, the most eff ective strategy is to use a nutrientPLANTS How do I keep my plants red? rich substrate while keeping nitrogen levels low in the water column. Substrates can be enriched using root tabs high in ammoniacal nitrogen and lean nitrate in the water can be achieved by simply using an all-in-one fertiliser without nitrogen. In this case I can recommend The 2Hr Aquarist’s APT Zero fertiliser and APT Jazz for root tabs. Another crucial element is increasing the lighting intensity, which correlates with more vibrant colours. But care must be taken to avoid excessive lighting that might trigger algae problems. Some species thrive under stronger lighting, while others might not need it, so thorough research into individual species is recommended. Some more forgiving plants that don’t require as intense lighting and will do okay without CO2 injection include Alternanthera reineckii, Ludwigia ‘mini super red’ and Nymphaea lotus. Colours won’t be as vivid without CO2 and stronger lighting, but they will remain red. Rotala rotundifolia will grow reddish under stronger light and low nitrate conditions even without CO2 , although it helps. Picking the right variety of Rotala such as ‘blood red’, ‘colorata’, or ‘H'ra’ will make a huge diff erence to the results. The spectrum of lighting plays a pivotal role in plant growth and appearance. Lighting which has more red and blue within the spectrum intensifies the visual impact of red plants. Nymphaea lotus. ABOVE: Rotala can be a deep red colour. BELOW: CO2 injection will boost reds.

AWARD WINNING PRODUCTS Send your questions to: Fishkeeping Answers, Practical Fishkeeping Magazine, Warners Publishing, The Maltings, West Street, Bourne, PE10 9PH. Email us at [email protected] ADVICE 44 How should I dispose of old or expired aquarium chemicals such as test kits, medications and conditioners? RUFUS THOMPSON-COX NEALE REPLIES: This is a really good question, but as far as I know, there isn’t a consistent best practice to this one. As with human medicines being returned to the pharmacy where you got them, any unused or expired fish medicines you’d obtained from a vet could be returned to them, as they’ll take steps to ensure the medication is properly disposed of safely. But over-the-counter fish medicines are not handled in the same way. Now, one reason for that is that the medicines we get without prescriptions are generally very low on the toxicity scale. Or rather, they’re the sorts of chemicals that oxidise or otherwise break down very quickly, unlike some of the persistent pharmaceutical drugs that are known to cause problems in rivers and lakes. Another factor is that the medicines we use are often relatively simple compounds that, if you keep them in the dark and in a tightly closed bottle, will be useable for years and years. Most of the old school fish medications based around organic dyes are going to fall into this category, and for a long time were sold without ‘use by’ dates of any kind. They might become a bit lumpy as some of the chemicals settle out, but a good shake or stir until everything dissolves again should fix that. Finally, some of the chemicals we use are generally regarded as having such low toxicity that by the time they’re diluted in the sewerage system, the threat they pose to fish and plants is negligible. Tapwater conditioner, which is based around sodium thiosulphate, is an example of this sort of thing, and let’s face it, since it’s used to make tap water safer for aquarium fish and plants, there’s no reason to imagine it does any harm to fish and plants in the wild. Put another way, anything you’d put into the aquarium, and then flush out with a water change, isn’t going to be any more dangerous if you just pour it down the drain straight from the bottle. By the time it hits the sewerage system, the diff erence in concentration will make no practical diff erence at all. Test kits are much trickier. There’s no established protocol here of any sort, and I think for the most part, everyone just assumes they’re used up long before the chemicals ‘go bad’ in any meaningful way. There isn’t, to the best of my knowledge, any obligation on the part of the aquarist to dispose of test kits in a specific way since the volume of chemicals in these products is so small. Your local secondary school dumps vastly more hydrochloric acid, for example, down the drains in a single chemistry lesson than you’ll have in your nitrite test kit. That said, your local council should be able to provide specific advice to disposal of such chemicals. This may involve driving to your local waste disposal centre and handing the bottles over to one of the people working there, or they may tell you that the amounts are so small you can safely dispose of them with your non-recyclable waste. NEIL HEPWORTH TETRA PRIZE Rufus wins a box of Tetra goodies: 100ml TetraMin and TetraPro Colour foods, Holiday Food, Pleco Algae Wafers, FunTips Tablets, 100ml SafeStart, EasyBalance and AquaSafe TROPICAL How should I dispose of aquarium chemicals? If in doubt about the best way to dispose of an aquatic treatment, contact the manufacturer, and they should be able to tell you how to safely and legally dispose of any of their products. Question of th e Month Dechlorinator is harmless. Sewage farms can handle a lot. SHUTTERSTOCK

SCAN ME FOR EXPERT POND CARE AND ADVICE 45 What do I need for a healthy clam? MARINE Please can you off er some advice about getting a cultured clam for my 1.2m reef tank? It currently houses LPS and pulsing corals and two common clowns and a firefish, plus some reef hermits. The tank has a sump with skimmer and is lit with TMC Aquabeam LEDs. Everything is growing and I’ve had no problems so far. It has been set up for four months. I’m still stocking the tank so are there any fish I should avoid with a clam? I’ve seen some small bristleworms in the tank and I’ve read they can be a problem with clams. Is this true and if so, do I need to get rid of them? STUART BOOTH JEREMY SAYS: Tridacna spp. clams are beautiful but there are a few things they need. The first is bright light. Either hire a PAR meter, or invest in a PARwise par meter, which measures the brightness of light in your tank. Clams are best placed on the bottom of the tank where you can admire them, but I’d recommend very bright light of 350 PAR on the bottom if they are to be happy, as they inhabit sun-drenched shallow waters in the tropics. Not enough light and your clam may fade away and die. Secondly, they need alkalinity, calcium and magnesium, along with trace elements in order to survive, grow and build their shells. Arm yourself with reef test kits and test daily for those three parameters before setting up a daily dosing regime, using an auto doser to keep levels in check. Get the largest clam you can aff ord and add liquid phytoplankton and liquid zooplankton as food. Bristleworms are only a problem in tanks which are overfed. However, four months is still immature in reef tank terms, with one to two years being normal before maturity is reached, so I’d maybe wait a bit longer before purchasing your clam. This will give you plenty of time to test your water and measure those light levels. I have a Superfish QubiQ 60 nano tank on which the hinge and fixing mechanism for the built-in light has become unstable, with the whole unit at risk of falling off . So, I’ve been using a Leddy clip-on light instead, but I think it’s far too bright for my elderly female Betta splendens, whose eyesight is failing – she’s otherwise healthy – and it makes it even harder for her to find food. Would a Superfish Nano LED 0.6 light be more suitable? She was happy with the brightness level of the original light. I want her old age to be blissful. NICK MARTIN JEREMY REPLIES: The Superfish QubiQ 60 comes with a 12W LED light, although it is dimmable. The Superfish Nano LED 0.6 uses just 0.6W of energy, so will be considerably dimmer as it uses just one twentieth the power of the original light, and its output will be reflected in that. It will certainly not be too bright for your elderly Betta, but I fear it will be underpowered for your 60-litre tank and would struggle to light the whole area while also not providing enough light to grow plants. The Leddy clip on light is just 6W, so although it may appear bright, I don’t think it’s too bright for an aquarium of that size, and I would recommend a fixture of at least 5W to light a 60-litre cube aquarium. I’d keep the Leddy clip-on and shade the surface with floating plants, tint the water with blackwater extract, or both. I just don’t think the tiny 0.6W LED light will be anywhere near powerful enough. TROPICAL Is this light too bright? FLAME! Clams can be the target of many fish, such as angelfish— including dwarf angels—and butterflyfish, which tend to nibble at the soft mantle, so you’ll need to avoid those if adding a clam. SHUTTERSTOCK SHUTTERSTOCK Clams need mature tanks.

ADVICE TROPICAL AWARD WINNING PRODUCTS Send your questions to: Fishkeeping Answers, Practical Fishkeeping Magazine, Warners Publishing, The Maltings, West Street, Bourne, PE10 9PH. Email us at [email protected] 46 I'd like your advice on fish for a 400-litre mbuna set-up please. I'm worried about hybridisation and my question is whether a male will hybridise with other females even if he has females of his own species to breed with. I'm thinking of keeping a group of Pseudotropheus saulosi alongside a group of P. demasoni but I'm worried there might be conflict or hybridisation risks. What's the safest route for a Will these mbuna hybridise? complete beginner to these cichlids? I've been keeping community fish for five years but mbuna are a new adventure. HELEN COOK JEREMY ADVISES: Unfortunately, there is a definite risk of hybridisation between Pseudotropheus saulosi and demasoni, even if you provided Frequent water changes can lower aggression levels in mbuna set-ups by diluting the pheromones in the water. half a dozen females of each to a male. The male’s inky blue vertical markings are just too similar, gorgeous as they are, and they are probably already quite closely related. Researchers have proved that natural hybridisation played a part in the hundreds of species now present in the lake, and I personally had hybridisation occur in mbuna tanks of over 1000 litres in volume. To try to alleviate this I would choose either P. demasoni or saulosi, then mix with a Labidochromis, Metriaclima, Melanochromis, Labeotropheus, Cynotilapia, Tropheops species etc., and try to keep the adult colours and patterns contrasting and not too similar. When stocking a mbuna tank I always cycle the filter first, then start with the least aggressive species, such as Labidochromis caeruleus or Pseudotropheus acei, adding at least two females to one male, and usually just one male of each species. I use plenty of rockwork, add the mbuna when young and around 5cm in length—they are all less aggressive when juveniles—and add at least six, if not 12 fish in one go. Once you get to 24 fish in total you could add single Cynotilapia or Pseudotropheus elongatus males, although try to choose species with patterns diff erent to your resident Pseudotropheus. Feed vegetable-based dry foods, avoid bloodworm, keep the water hard and alkaline, filter well, and ensure there is plenty of oxygen. SHUTTERSTOCK NATHAN HILL Melanochromis auratus. Pseudotropheus demasoni.

TEACHING CHILDREN ALL ABOUT FISHKEEPING 47 I'm planning an African themed setup with Congo tetras as the main fish. The tank is 120x45x45cm. I wondered if you could recommend a Synodontis catfish species I might be able to keep in this set-up and also one of the African gourami species? It has two internal filters and is furnished with Anubias and Bolbitis with a fine gravel substrate and rocks. Any advice would be welcome. How many Congos should I get and what sort of sex ratio is best? JOE GREENWOOD BOB REPLIES: Congo tetras, Phenacogrammus interruptus, are beautiful fish, well worthy of a tank with them as the centrepiece. I would get a group of 12, with a mixture perhaps of eight males to four females. You need a mix of sexes to see the best colours and displays among males. The problem with this is that most fish are sold as dull, juveniles which are impossible to sex and if you're unlucky—as I have been in the past—you can end up with a tank full of females. More mature fish are sometimes available with the males’ tails giving them away. With regards to Synodontis, then there are plenty to choose from, but they can be diff icult to source as they've fallen somewhat out of fashion, possibly due to the large number of hybrids that have flooded the market. If you can find them, then the pyjama catfish, Synodontis flavitaeniatus, is a great choice, and TROPICAL Which tankmates for a Congo tetra set-up? unlikely to be mixed up with hybrids. As their common name suggests, they are marked with attractive orange/yellow horizontal stripes over a brown background. These are relatively small fish in aquariums, compared to many synos, growing to around 12cm. They also have the benefit of being tolerant of their own kind, so can be kept in small groups. Like most catfish they can be shy but adding plenty of wood and plants as hiding places, and stocking a small group will make them bolder, especially when food is on off er. With regards to gourami, I assume you mean Ctenopoma, which are lovely fish, with the leopard bushfish, Ctenopoma acutirostre being the one most commonly seen. They can be a little aggressive and will predate fish small enough to fit into their large mouths, so if you do want to risk one, I'd add it last, as a small specimen, once the Congos have had a chance to mature and grow to a size where the Ctenopoma won't consider them as food. Congo tetra male. Leopard bushfish. SHUTTERSTOCK SHUTTERSTOCK

ADVICE ALAMY Watch for the tiny strands of Macrogyrodactylus. Gyrodactylus are microscopic. GLOBAL LEADER IN AQUATICS Send your questions to: Fishkeeping Answers, Practical Fishkeeping Magazine, Warners Publishing, The Maltings, West Street, Bourne, PE10 9PH. Email us at [email protected] 48 I had a pair of Polypterus senegalus in one of my tanks with no other inhabitants, for around four years. For most of that time they both had very fine short ‘hairs’ across their whole body which didn’t seem to bother them —they seemed active, healthy, were eating well and growing steadily, with both at around 17-18cm. But in the last month the female developed terrible bloat and died within a week. Meanwhile, the male lost an eye and now seems quite lethargic, although he is eating. I think these hairs must be some sort of parasite, but I can’t work out what or how to treat them. I’ve tried a general malachitebased parasite treatment, but it has had no eff ect. Do you have any thoughts on this at all? I have included a recent photo of the male. There seems to be a ‘hair’ in his good eye now, which is a little cloudy. RICHARD COOKE NATHAN RESPONDS: Ah, now here’s a rarity! Your bichirs are suff ering from a disease which I’ve only become familiar with quite recently (it was only HEALTH What are these parasites on my fi sh? described in 2008, and I only learned of it from The Bichir Handbook) and which appears to target polypterids. The disease in question is a parasitic infection, caused by the skin fluke Macrogyrodactylus simentiensis. You might be familiar with the second part of that generic name—Gyrodactylus—as many of us (especially pond keepers) have wrestled with it in the past. Unlike Gyrodactylus, you don’t need a microscope to see Macrogyrodactylus as they’re so large that they can be seen with the naked eye, and that’s what those tiny ‘threads’ present are—adults brimming with young. They’re also surprisingly mobile, worming their way up and down the fish in search of fresh feeding spots. These livebearing flukes can hold several generations of off spring in a single adult—under a microscope, you’ll be able to see not just a young Macrogyrodactylus inside the adult, but an even smaller one inside of that unborn juvenile! Thankfully, treatment is pretty straightforward. A single five-day course of eSHa Gdex will usually be more than enough to see them off , and at time of writing I see that a 20ml bottle (which treats 300 litres) has a retail price of £9.69. Alternatively, another treatment containing praziquantel will work. Whatever you do, don’t be tempted to add an off -the-shelf parasite treatment containing copper, as polpterids are sensitive.

Xenia can be rampant. JOIN US ON FACEBOOK & INSTAGRAM: TETRA UK 49 TROPICAL SHUTTERSTOCK Will my fi sh be okay while I’m away? I'd like to go on holiday for a month, but we have three Juwel 180 tropical tanks. All have internal filters and easy-to-keep fish. I can get someone to feed the fish, but how often will they need to do this? I can’t expect them to do water changes or filter cleaning though. Do you have any advice please? RICHARD HUDDLESTON BOB SAYS: If you have someone you can trust to follow a precise feeding regime, then I wouldn’t worry too much about your impending holiday. Feed up the fish up with a range of good quality foods—fresh, frozen and dried—in the fortnight before you are due to leave, to get them into top condition. Give the filters a good clean about a week before you go (but no later than that), and if you have filter media such as carbon that’s near the end of its life, then consider replacing it. Carry out a moderate, say 25%, water change as close to the day you’re planning on leaving as possible. With regards to feeding, the fish should be fine for the first week without any food. I would then recommend small twiceweekly feeds. Measure the food out into ‘wraps’ of foil, small bags, or similar to prevent over-enthusiastic helpers giving too much for the remaining time. With this minimal feeding regime, the water quality shouldn’t suff er unduly during your absence, and you can then carry out a big water change on your return to get things back to how they were, before switching back to your regular feeding and cleaning routine. MARINE Why won’t this ‘weed’ grow? I have a Fluval Flex marine tank, with a volume of approximately 120 litres and for some reason I'm unable to grow Xenia. I've tried three times now with frags but I find it just disappears within 2-3 weeks, yet I’m keeping other corals with no problem. I was told it grows like a weed—but not in my tank! I have a royal gramma, two tiny clownfish and a peppermint shrimp. Could something be eating it? B. HICKS JEREMY SAYS: Two common soft coral genera are referred to as Xenia. Green ‘xenia’ – also known as green star polyp (or GSP), and Pulsing Xenia. Although hardy regarding salinity, temperature, nutrient levels and water chemistry, they both need quite bright light, some nitrate and phosphate, iodine, and iron, with iodine probably being the quickest fix to make them come round. I love the Fluval tanks, but their lights aren’t super-bright. I’d place both corals at the top, underneath the light, to see if that improves things. If adding iodine, bright light and a nitrate level of 10 or above doesn’t do it, I would suspect you have a rogue, hungry peppermint shrimp that is dining on your Xenia frags. But if you improve all the above, it should indeed grow like a weed. Xenia will pulse less in tanks where there is a lot of water movement. Its pulsing action is a method of drawing oxygen over itself, and if there is plenty of flow it has less reason to do this. Measure out food for helpers. SHUTTERSTOCK

EVERYTHING YOU NEED 50 FOR HEALTHY FISH ADVICE Send your questions to: Fishkeeping Answers, Practical Fishkeeping Magazine, Warners Publishing, The Maltings, West Street, Bourne, PE10 9PH. Email us at [email protected] TROPICAL I have a 150-litre tank housing two 17cm axolotls. Back in March there was a detritus worm outbreak. I'm aware that these worms generally manifest in tanks with overfeeding, excess waste and poor hygiene, but this was never the case in my set-up. They aren’t overfed, and water changed regularly. Ammonia and nitrite have always remained at zero and nitrate is minimal. The tank is bare bottomed with slate caves. I believe the worms were introduced via live bloodworms bought online. I generally empty the bag of live food into a net and thoroughly wash them under a tap before feeding to the axolotls. Within a couple of weeks the detritus worm took hold and numbers increased rapidly. Despite repeated water changes and wiping the glass, I couldn't get rid of them and stripped the tank to start all over again. The axolotls enjoy live river shrimp, which I feed as a treat, but I’m worried about introducing any unwanted creatures or diseases again. Should I stop feeding live food altogether or is there a way to screen it prior to feeding? MAJID ALI Is it safe to feed live foods? NEALE SAYS: The 'detritus worm’ name is used by fishkeepers to refer to non-parasitic worms found in aquaria. These can be a range of diff erent things, including free-living nematodes— probably ubiquitous to all aquaria—and small oligochaete worms such as Tubifex or Lumbriculus species. Nematodes tend to be small, semi-transparent, lack segments, and have distinctly pointed ends. They often adhere to the glass walls of the tank, or else can be seen in the gaps between gravel particles. Oligochaetes are segmented worms, usually darker pinkish brown to red in colour, and can get a lot bigger. They are eff icient burrowers, but some species burrow one end into the substrate while the other end sticks out into the water, and waves about to absorb oxygen or catch food particles. You could reduce the population by treating with an antihelminthic, either choosing one known to be safe with amphibians, or with the axolotls in Did you know? Tubifex worms are well-adapted to stagnant or polluted water and are used as indicator species by ecologists for determining the health, or otherwise, of rivers and streams. another aquarium for the duration, but the worms would eventually come back if you didn’t change your approach to feeding and maintenance. It’s a bit like dealing with algae and snails in aquaria: yes, there are ways to kill them in one fell swoop, but they’ll come back soon enough if you give them a chance. There is no reason at all to be using live food with axolotls. As you’ve discovered, anything alive has the potential of bringing in unwanted pests. Earthworms are generally safe because anything on or inside them won’t be adapted to living underwater, so they’re probably the best choice if live foods are required. Likewise, brine shrimps are favoured by many because their hypersaline environment is essentially deadly to anything that might infect pet fish or amphibians. River shrimps, in the UK at least, are brackish water species taken out of places like estuaries and salt marshes, so it’s very unlikely they’ll carry anything that could harm freshwater fish, let alone amphibians. But once you start looking at things that live in ordinary freshwater, such as bloodworms and Tubifex, things get messy. I’d advise buying the frozen ones as the freezing process ensures the food is absolutely pest and parasite free. Axolotls can’t tell the diff erence between frozen and live bloodworms, so it’s all good on that front. Above a certain size, it’s usually easier to feed them chunky fish and seafood, plus the occasional earthworm if you want, and I use long forceps for this, wriggling the food in front of them. So long as you use a nice variety of such foods you should find your pets thrive. CREATIVE COMMONS ABOVE: River shrimp. BELOW LEFT: Bloodworm.