1.Parasitism
Parasites are organisms that live on or in a host organism. The parasite benefits from this arrangement, but the host suffers as a result. Fleas are parasites. They live on the skin of other animals and suck their blood. This feeds the flea but weakens the host.
2.Protocooperation it is positive interaction in which both species will be benefited but they can live equally well without this association
3.Commensalism of two living Animals
An example of commensalism: cattle egrets foraging in fields among cattle or other livestock. As cattle, horses and other livestock graze on the field, they cause movements that stir up various insects. As the insects are stirred up, the cattle egrets following the livestock catch and feed upon them. The egrets benefit from this relationship because the livestock have helped them find their meals, while the livestock are typically unaffected by it.
4.Predators
Predation is an interaction between animals in which one captures and feeds upon another called the prey. The predator is usually the larger and stronger of the two. Predators are always either carnivores or omnivores. The prey might typically be a herbivore, but some predators feed on anything they can capture, including other predators.
As prey have developed defenses such as mimicry, chemical defense, camouflage or warning systems in order to evade predators, predators have developed skills and weapons to seek and capture a meal. Raptors are an interesting example of how every part of the bird is designed/adapted to be successful in obtaining food.
Predators are necessary to an healthy ecosystem. Without these animals, prey species may drive others to extinction through competition for food.
5.Competition
Populations of animals are controlled by many factors. Natural selection is a broad term that describes one effect of these controls on population. For example, one form of population control that can result in natural selection is competition.
6.antibiosis
Other antagonists produce substances that inhibit or kill potential pathogens occurring in close proximity. An example of this process, called antibiosis, is provided by marigold (Tagetes species) roots, which release terthienyls, chemicals that are toxic to several species of nematodes and fungi.
7.Neutralism
In a case of true neutralism, two populations interact, but neither would have any effect on the evolutionary fitness of the other. Because all organisms in an ecosystem are interconnected in some way, true neutralism is not likely to occur, and would be very difficult to prove. The term is often used to describe interactions in which the effects of two populations on each other are simply negligible. Say....a Bactrian Camel and a Longtailed Tadpole Shrimp, both living in the Gobi desert
8.mutualistic
A mutualistic relationship is when two organisms of different species "work together," each benefiting from the relationship. One example of a mutualistic relationship is that of the oxpecker (a kind of bird) and the rhinoceros or zebra