Answer:
habitat isolation.
Step-by-step explanation:
There are several isolation mechanisms that prevent two organisms from reproducing, as a result, a barrier occurs between the genes of the two organisms through reproduction.
One type of isolation mechanism is habitat isolation, which occurs when two organisms of the same species or genus are prevented from reproducing because they live in the same region, but in different habitats. An example of this can be seen in the question above, where despite being in the same region, one organism lives mainly in water, while the other spends most of its time on land.