Behavioral Isolation — Definition & Examples

Two populations of a fish species live in a coral reef. The fish only spawn after a mating pair do a complicated swimming dance. The two populations have dances that are slightly different, and it is rare for them to dance together. When they do dance together and spawn in the same area, the sperm fertilizes the egg, but the resulting offspring usually is not successful in mating.

What kinds of isolation happened to these fish and in what order?