What is the name of the male seahorse's pouch where embryos develop?

A male seahorse's brood pouch is where embryos develop. During mating, the female transfers eggs into the male's pouch, where he fertilizes them and provides a protected environment for development.

The pouch is more than a simple storage pocket. Its lining helps regulate conditions around the embryos, including oxygen and waste exchange. Near birth, the male uses muscular contractions to release fully formed young into the water.

Seahorses are unusual among vertebrates because the male, rather than the female, carries the developing offspring. This reproductive arrangement occurs in seahorses and their close relatives in the pipefish family, although pouch structure and parental roles vary across species.

A common mix-up is to call the pouch an egg container only. The eggs begin in the female, but after transfer they are fertilized and incubated in the male's brood pouch. The young are still independent animals when released and receive no prolonged parental care comparable to that of many birds or mammals.