(a) Commensalism: Commensalism is an interaction between two species in

which one species gets benefited while the other remains unaffected. An orchid

growing on the branches of a mango tree and barnacles attached to the body of

whales are examples of commensalisms.

(b) Parasitism: It is an interaction between two species in which one species

(usually smaller) gets positively affected, while the other species (usually larger)

is negatively affected. An example of this is liver fluke. Liver fluke is a parasite

that lives inside the liver of the host body and derives nutrition from it. Hence,

the parasite is benefited as it derives nutrition from the host, while the host is

negatively affected as the parasite reduces the host fitness, making its body weak.

(c) Camouflage: It is a strategy adapted by prey species to escape their

predators. Organisms are cryptically coloured so that they can easily mingle in

their surroundings and escape their predators. Many species of frogs and insects

camouflage in their surroundings and escape their predators.

(d) Mutualism: It is an interaction between two species in which both species

involved are benefited. For example, lichens show a mutual symbiotic 

relationship between fungi and blue green algae, where both are equally benefited

from each other.

(e) Interspecific competition: It is an interaction between individuals of

different species where both species get negatively affected. For example, the

competition between flamingos and resident fishes in South American lakes for

common food resources i.e., zooplankton.