Exclusive male parental care is observed much more frequently in species with external fertilization?

Question

where the males genetic contribution to the offspring is more certain. explain how such behavior could evolve.

explain how such behavior could evolve

Answer 1

That could be true if the male, like in damsel fish, establish a territory and females lay eggs in his territory which he protects.  Internal fertilization usually means the female controls the eggs so the male would have to follow her around until she laid the eggs.  That isn't likely to lead to exclusive male parenting.