Protozoan and Helminth Parasites of Earthworms (Alma ...

Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 4(2): 293-295
© Scholarlink Research Institute Journals, 2013 (ISSN: 2141-7016)
jJeotueransa.slcohfoElamrleinrgkirnegseTarcehn.dosrgin Engineering and Applied Sciences (JETEAS) 4(2):293-295 (ISSN: 2141-7016)

Protozoan and Helminth Parasites of Earthworms
(Alma millsoni and Libyodrilus violaceus)

1W.A. Abimbola, 2Amoo A.O.J., 1Owa, S.O

1Parasitology Laboratory, Department of Plant Science and Applied Zoology,

Olabisi Onabanjo University, P.M.B. 2002, Ago-Iwoye, Ogun State, Nigeria.
2Department of Medical Microbiology and Parasitology,

Olabisi Onabanjo University, P.M.B. 2002, Ago-Iwoye, Ogun State, Nigeria.

Corresponding Author: W.A. Abimbola

__________________________________________________________________________________________
Abstract
Earthworms are now considered in animal feeds; especially as alternative for fish meal and source of protein.
Based on these, therefore the need to study protozoan parasites becomes imperative due to zoonotic effect. One
hundred and forty earthworms (75 of Alma millsoni and 65 of Libyodrilus violaceus) commonly found in Ago-
Iwoye, Ogun State, Nigeria; were collected during the raining months of May, June, July and August 2006 by
digging and hand sorting method. The worms were dissected and examined for protozoan and helminth
parasites. Of the 75 individuals of A. millsoni sampled, 46 (61.3%) were infected with protozoans namely
Apolocystis libyodrilii, Monocystis abegei, Monocystis libyodrilii, and L. violaceus had 83.1% prevalence of
protozoan infection with an overall mean prevalence of of 72.2%. Chi-square analysis of the population of
Apolocystis libyodrilii, Monocystis abegbei, and Monocystis libyodrili revealed a significant difference in
Libyodrilus violaceus than in Alma millsoni at p<0.05. The present results of the study provide basic
information on possible parasites of earthworms which may be transmitted to livestock or other animals when
fed with these earthworm species. Potential vermiculturists need find ways of eliminating these parasites from
the earthworms during processing of the worms for use as protein source.
__________________________________________________________________________________________
Keywords: Protozoans, Earthworms Alma millsoni, Libyodrilus violaceus. Ago-Iwoye

INTRODUCTION of worms and nematodes parasitic in birds and
Earthworms are among the most widespread of mammals. These protozoan parasites and worms
invertebrate animals and are found mainly in the soils could cause considerable damages to lungs, and other
of grasslands, woodlands, scrublands and forest. organs in animals. Example is the Cappillaria worms
Earthworms are diverse in forms and in behaviour. which may attack the lining of the digestive tract of
They could be aquatic or terrestrial in nature. dogs. Flukes also may, directly damage the liver,
Earthworm contains adequate amount of essential lungs, intestines or they may act as carriers of other
amino acids, adequate mineral content, about 98% disease agents (Bodner, 2007). Earthworms have
digestible animal protein and comparable fatty acid been reported as vectors of an animal virus, which
profile essential for fishes, birds, pets and all animals causes the foot and mouth diseases of domestic
(Dynes, 2003). The earthworm meal has a high animals (Dhennin, 1963). Many animal parasites are
protein and balanced amino acid and fatty acid transmitted from host-to-host by earthworm, which
profile, making it a good alternative source for makes them either essential intermediate hosts or
substituting mainstream feeds of fishmeal. As baits, mere reservoir hosts to the parasites (Edwards and
earthworm is believed to have chemo stimulating Lofty, 1977), transmitting them without any direct
features that attract animals. Many of these influence on the parasites life cycle. Earthworms are
characteristics of the earthworm promote its use as essential intermediate host to a number of tapeworms
raw material for formulating feeds for all kinds of (cestodes) and nematodes parasitic in birds and
animals (Selvan 2005). mammals (Hutchison and Kamel, 1956). The study
therefore was based on the need to assess and identify
Utilization of these earthworm species is possible; protozoan parasites of earthworm in view of the fact
however their ability to harbour parasites and that they are included in feeds for domestic animal
pathogens may constitute a problem to their use as production which has implication for food safety in
inclusion in animal feeds. Owa et al, (2005) reported human population.
the presence of different species of bacteria in
Lumbricus terrestis and Libyodrilus violaceus. MATERIALS AND METHODS
Edwards and Lofty, (1977) also incriminated The study was carried out in Ago-Iwoye, Ijebu North
earthworms as intermediate host for the transmission Local Government Area of Ogun State, Nigeria. Ago-

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Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 4(2):293-295 (ISSN: 2141-7016)

Iwoye is geographically located in the coordinates: 6° STATISTICAL ANALYSIS
57' 0" North, 3° 55' 0" East Earthworm samples were The data collected were statistically analysed using
collected from different locations during the rainy SPSS version 11 into frequency count and
months of May to August year 2006 by digging and percentages. The Chi-square analysis was done to
hand picking method (Owa, 1994). determine the significance and difference in the
incidences of protozoan ova found in the sampled
Laboratory analysis, which included earthworm population of earthworms and also to determine the
sorting, identification, dissection and techniques for relationship of infections and the earthworms.
identifying parasites within the earthworms, were
carried out in the laboratories of the Department of RESULTS
Plant Science and Applied Zoology, Olabisi The results of the study revealed the presence of both
Onabanjo University, Ago-Iwoye. Identification of protozoan parasites in the earthworms Alma millsoni
the parasites was made according to descriptive and and Libyodrilus violaceus. The protozoan parasites
identification account of Segun, (1978), while identified are Apolocystis libyodrilii, Monocystis
helminths ova identification was according to abegbei and Monocystis libyodrilii. Table 1 shows
description of Cheesebrough, (2000). the proportion of the earthworm species sampled. 75
(53.6%) of Alma millsoni and 65 (46.4%) of
DISSECTION AND SLIDE PREPARATIONS Libyodrilus violaceus were sampled. The prevalence
140 earthworms were dissected in all comprising 75 of Monocystid Protozoans in both species of
individuals of the Alma millsoni and 65 individuals of earthworm sampled were; Apolocystis libyodrilii, 63
the Libyodrilus violaceus respectively. After (27.2%); Monocystis abegbei, 78 (33.6%) while
collection, the earthworms were anaesthetized in 50% Monocystis libyodrilii, 91 (39.2%), (Table 2). Table 3
alcohol as described by Morholt, et.al; (1966) for 5- shows the incidence of protozoans in individual
10 minutes. The anaesthetized worm was dissected specie of the sampled earthworms. The incidences are
ventro-laterally (in 0.65% saline) to allow easier significantly higher in Libyodrilus violaceus than in
access to most of the internal organs. The tissues and Alma millsoni.
organs to be worked on were located and
immediately examined for helminths and protozoan Table 1: Species of Earthworms sampled.
parasites (Segun, 1978). The organ to be examined
was removed with sterile forceps and smeared on Earthworm species F (%)
clean and grease free slides, one as a wet mount
smear preparation (Phillip, 1998) with few drops of Alma millsoni 75 (53.6)
0.65% earthworm saline added, and covered with a
cover slip which was examined under the binocular Libyodrilus violaceus 65 (46.4)
microscope. The second slide had a drop of
methylene blue added to it and was covered with a Total 140 (100)
cover slip and examined under the binocular
microscope. Source: Field Study 2006

Table 2: Prevalence of Monocystids in the sampled
population of earthworms

Wet mount squash was prepared using an isolated Monocystids F (%)
seminal vesicle. The organ was teased apart in a drop Apolocystis libyodrilii 63 (27.2)
of earthworm saline on a slide and a drop of Monocystis abegbei 78 (33.6)
methylene blue was added and covered with a cover Monocystis libyodrilii 91 (39.2)
glass. It was squashed using the thumb (covered with
a piece of paper), and examined under the Total 232 (100)
Source: Field Study 2006

microscope. Permanent smears were made, by

smearing the organ on a slide and air-dried. It was Table 3: Incidences of Protozoan ova in the sampled
stained using Erhlich’s haematoxylin for 3mins. It
was then rinsed in tap water. 0.1% sodium population of earthworms
bicarbonate was dropped on it for about a minute or
until specimen is distinctly blue in colour, after which A.millsoni L.violaceus X2 P-value

Freq. (%) Freq. (%)

Protozoans

it was thoroughly rinsed in tap water. This was then A. libyodrilii 15 (20.0) 48 (73.0) 40.79 <0.05

counterstained with eosin in 70% alcohol for about M. abegbei 30 (40.0) 48 (73.0) 16.17 <0.05
45 seconds and rinsed in 95% ethyl alcohol by M. libyodrilii 42 (56.0) 49 (75.4) 5.75 <0.05

dipping momentarily and then drained. This was

repeated for a few times, dried and mounted in

Canada balsam with a cover glass and allowed to

harden (Morgan, 1996). Source: Field Study 2006

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Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 4(2):293-295 (ISSN: 2141-7016)

DISCUSSION AND CONCLUSION Dynes, R. A (2003): Earthworms Technology
Results of this study show trends, which agrees with information to enable the development of earthworm
Segun (1978) in which six Monocystid species were production: A report for the Rural Industries
found in the earthworm Libyodrilus violaceus. The Research and Development Corporation (RIRDC).
present study sampled 75 and 65 specimens of Alma Australia, pp 1-39
millsoni and L. violaceus, with both species showing
protozoan parasites infection. The presence of Edwards, C. A. and Lofty, J. R (1977): Biology of
Monocystis libyodrilii, Monocystis abegbei and Earthworm, 2nd edition, Chapman and Hall, London.
Apolocystis libyodrilii has been reported by Segun
(1978). However, the presence of this species in A. Hutchison, S. A. and Kamel, M. (1956): The effects
millsoni is being recorded for the first time. The of earthworm on the dispersal of soil fungi. Journal of
occurrence in A. millsoni is may likely be connected soil science 7(2) 213-81.
with both species sharing the same habitat
(limicolous environment). Morgan, M. (1996): Earthworm Discussion Miscape
Article. Earthworm Dissection. http:/www.
However, the limitation encountered in the course of microscopy.uk.org.uk/mag/articles/worm.html.
the study greatly lies in the impossibility to calculate
and compare the percent prevalence in both species Morholt, E. P., Brandwein and A. Joseph (1966): A
with any previous work since there was no literature Sourcebook for the Biological Sciences, 2nd Edition,
on this and. The presence of the found Monocystids New York Harcourt Brace and World Inc.
in A. millsoni is at variance to Segun (1978) that the
Monocystids species are host specific, since the ones Owa, S. O. (1994): Description of two new
recorded in this study have only been found earlier in Iridodrilus species and a re-examination of the
L. violaceus. Various methods of infection of earthworm genera Heliodrilus Beddard and Segunia
earthworms by Monocystids have been suggested, the Sims (Annelida: Oligochaeta: Eudrilidae). J. Nat.
principal means is probably by the ingestion of Hist. 28(1): 9-25.
sporocysts containing infective sporozoites. The
finding of helminth ova indicates soil contamination Owa, S.O; Mabekoje, O.O; Olowoparija, B. (2005):
by human and animal activities, and the viability of (Unpublished) – Determination of Microbial
these parasite ova under different environmental Composition of the enteric regions of the earthworm
condition is a focus in transmission of zoonotic L. violaceus. Beddard, 1891.
diseases.
Phillip. S. (1998): Monocystids: Earthworm Parasite.
The results of the present study hold a lot for Practical Aid, Carolina Biological Supply Company.
intending vermiculturists and anyone interested in the Burlington, North Carolina 27215
use of earthworms as alternative source of animal
protein in livestock, animal or fish diet. The study Segun, A. O. (1978): Monocystid Gregarine Parasites
had provided information that parasitic protozoans of Nigerian Earthworm. Journal of Protozoology, 25
(Monocystids) are present in the earthworms’ (2), 157-162
species. That A. millsoni had a lesser parasitic load
than L. violaceus and the possibility of the earthworm Selvan Bio. Tech (2005): Save fish with safe food.
serving as intermediate host in the transmission of http://www.selvanbiotech.com/page
zoonotic diseases. The study had provided baseline
information on possible parasites that an intending
user may have to contend with is now available.

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Cheesebrough, M. (2000): District Laboratory
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Dhennin, L. (1963): Investigations on the role of
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