E C O L O G I C A L I N T E R A C T I O N S A DIGITAL TEXT BOOK BY VIJITHRAA
IntroductionEcological Interaction Page 03 Mutualism Page 04 Competition Page 06 Predation Page 08 Parasitism Page 10 Commensalism Page 13 Ammensalism Page 15 Page 2 CONTENTS TABLE OF
Ecological interaction is defined as the relationship of two different or the same species that live in a specific community. This enables the balance of life in a specific community. Ecological interactions enable other organisms to benefit from the efforts and activities made by other organisms. Some of the types of ecological interactions are commensalism, competition, mutualism, and predation. Ecological interactions are innate in all ecosystems on the planet. This enables the circle of life to continue. Page 3 Ecological Interaction INTRODUCTION
Page 4 MUTUALISM Mutualism describes the ecological interaction between two or more species where each species has a net benefit. Mutualism is a common type of ecological interaction, one that can come from a parasitic interaction. Prominent examples include most vascular plants engaged in mutualistic interactions with mycorrhizal fungi, flowering plants being pollinated by animals, vascular plants being dispersed by animals, and corals with zooxanthellae, among many others. Mutualism can be contrasted with interspecific competition, in which each species experiences reduced fitness, and exploitation, or parasitism, in which one species benefits at the expense of the other.
mutualism, association between organisms of two different species in which each benefits. Mutualistic arrangements are most likely to develop between organisms with widely different living requirements. TYPES OF MUTUALISM Page 5 1. Obligate Mutualism Example- Lichen 2. Facultative Mutualism Example- Honeybee and flowering plants 3. Trophic Mutualism Example- Mycorrhiza 4. Defensive Mutualism Example- Acacia and Pseudomyrmex ants 5. Dispersive Mutualism Example- Ficus and fig wasps
Most of the competitive interaction occurs for the need of food sources that occur in a limited supply when compared to demand. However, organisms might compete for other resources like shelter, light, and substrate.The interaction often leads to a change in fitness between the organisms that share the same resources.Competition is one of the most important biological factors that determine the community structure in an environment.Between the two competing organisms, the weaker organism has to either adapt or die out while the stronger organism obtains the resources. Competition is most typically considered the interaction of individuals that vie for a common resource that is in limited supply, but more generally can be defined as the direct or indirect interaction of organisms that leads to a change in fitness when the organisms share the same resource. The outcome usually has negative effects on the weaker competitors. There are three major forms of competition. Two of them, interference competition and exploitation competition, are categorized as real competition. A third form, apparent competition, is not. Interference competition occurs directly between individuals, while exploitation competition and apparent competition occur indirectly between individuals Page 6 COMPETITION
TYPES OF COMPETITION 1. Intraspecific competition Example- Plants 2. Interspecific competition Example- Corals 3. Direct and Indirect Competition Example of Direct competitionAnimals Example of Indirect competitionAnimals 4. Interference, Exploitation, and Apparent competition Example of interference competitionFlamingos Example of exploitative competition- Spiders Example of apparent competitionSkinks Page 7
PREDATION Predation is a type of ecological interaction where one of the species kills and feeds on the other.The organism that kills and feeds on the dead organism is called the predator, whereas the organism that gets killed is called the prey.Predation is different from scavenging on dead organisms, but predators also scavenge as a part of their feeding behavior.Predatory organisms can either hunt as solitary hunters or group hunters where a group of species looks for prey together. Page 8
1. Carnivory Example- Wolves 2. Herbivory Example- Giraffe 3. Parasitism Example- Tapeworms 4. Mutualism Example- Gut microorganism in humans 5. Cannibalism Example- Black widow spider Page 9 T Y P E S O F P R E D A T I O N
Parasitism is generally defined as a relationship between the two living species in which one organism is benefitted at the expense of the other. The organism that is benefitted is called the parasite, while the one that is harmed is called the host. A few examples of parasites are tapeworms, fleas, and barnacles. Page 10 PARASITISM A symbiotic relationship in which a symbiont lives all or part of its life in or on a living host, usually benefiting while harming the host in some way and usually having a higher reproductive potential than the host.
Page 11 1. Obligate Parasitism Example- Rickettsia 2. Facultative Parasitism Example- Armillaria species 3. Ectoparasitism Example- Head lice 4. Endoparasitism Example- Plasmodium 5. Mesoparasitism Example- Copepods 6. Epiparasitism Example- In Plants 7. Brood Parasitism Example- Birds 8. Social Parasitism Example- Ants TYPES OF PARASITISM
Page 12 Parasitic plant, plant that obtains all or part of its nutrition from another plant (the host) without contributing to the benefit of the host and, in some cases, causing extreme damage to the host. The defining structural feature of a parasitic plant is the haustorium, a specialized organ that penetrates the host and forms a vascular union between the plants. PLANT PARASITISM
Commensalism is a type of relationship between two living organisms in which one organism benefits from the other without harming it. A commensal species benefits from another species by obtaining locomotion, shelter, food, or support from the host species, which (for the most part) neither benefits nor is harmed. Commensalism ranges from brief interactions between species to life-long symbiosis. Page 13 COMMENSALISM The term was coined in 1876 by Belgian paleontologist and zoologist Pierre-Joseph van Beneden, along with the term mutualism. Beneden initially applied the word to describe the activity of carcass-eating animals that followed predators to eat their waste food. The word commensalism comes from the Latin word commensalis, which means "sharing a table."
TYPES OF COMMENSALISM 1. Inquilinism Example- Scarab beetles and flies 2. Metabiosis Example- Hermit crabs and gastropod shell 3. Phoresy Example- Caenorhabditis remanei (soil nematode) and molluscs 4. Microbiota Example- Gut microbiota in human Page 14
Page 15 AMMENSALISM Amensalism is a specific type of asymmetric symbiotic relationship between different species in which one species is harmed or killed through its interaction with the other. In contrast, the other is at the most unaffected by the relationship Amensalism Vs. Commensalism These are both biological interactions. But amensalism and commensalism are totally opposite. Commensalism is the interaction in which one species benefits and the other species get harmed (+,-), and in amensalism, one species gets harmed and one neither gets harmed nor benefits.
TYPES OF AMMENSALISM Page 16 1. Antibiosis The word antibiosis, coined by Vuillemin in 1889-1890, is obtained from the French word ‘antibiosis, ’ meaning an antagonistic relationship between organisms. Thus, in antibiosis, one organism produces substances that harm other organisms. These substances can include toxins, chemicals, or metabolic byproducts that inhibit the growth or survival of neighboring species. An example of antibiosis is the release of antibiotics by certain fungi, which can hinder the growth of bacteria in the surrounding environment. 2. Competition This form of ammensalism arises when one organism actively competes with another for resources, leading to a negative impact on the latter. While the competing organism benefits from this interaction, the other organism is suppressed or inhibited. Competition can exist between an inferior and a superior species or between similar or different species. An example of competition is allelopathy in plants, where one plant species releases chemicals that impede the growth of neighboring plants, giving itself a competitive advantage.