Answer;
-Prezygotic; gametic isolation
This is an example of a prezygotic barrier called gametic isolation.
Step-by-step explanation;
-Prezygotic barriers are those barriers that prevents mating and fertilization is a prezygotic mechanism. Habitat isolation, behavioral isolation, temporal isolation, mechanical isolation and gametic isolation are all examples of prezygotic isolating mechanisms.
-Gametic isolation is a mechanism of reproductive isolation which inhibits mating between two distinct species, by ensuring that their gametes don't interact with each other. This incompatibility of gametes prevents the formation of inter-species hybrids, and maintains the integrity of the species.