Competition occurs when

In an aquarium two herbivorous species of fish are living together and feeding on phytoplanktons. As per the Gause’s Principle, one of the species is to be eliminated in due course of time, but both are surviving well in the aquarium. Give possible reasons.

Choose correct group for commensalism from the following

$(a)$ The cattle egret and grazing cattle

$(b)$ Barnacle balanus and Barnacle chathamalus

$(c)$ Goat and Abingdon turtle from Galapagosisland

$(d)$ Barnacles growing on the back of whale

There is more competition for survival between

Competition is best defined as a process in which the fitness of one species (measured in terms of its $' r '$ the intrinsic rate of increase) is significantly

Lower in presence of another superior species

In which of the following interactions both partners are adversely affected?