Answer:
Postzygotic reproductive barriers
Step-by-step explanation:
Individuals from two different species of goby fish will mate to produce a hetrozygote zygote which is unable to build the nest.
This happens because the gene pools of the two types of goby fish remained isolated prezygotically
Problems arising because of formation of hybrid zygote is known as postzygotic reproductive barriers. This inability leads to reduced ability of survival and reproduction which if persists for long could result into infertility of hybrid species.