In an opportunistic population, growth pattern is exponential.The populations are regulated by density-independent factors. Organisms produce plenty of gametes because the chance for fertilization is very low. The examples of the opportunistic population are insects, corals, oysters, etc.
In an equilibrium population, growth pattern is logical. The populations remain near carrying capacity. Organisms have much fewer offspring and take care of them. The examples of the equilibrium population are birds, mammals, and some fish.