In case you wanted the explanation from a 1993 Nirvana T-shirt: “Ever the trendsetter, the sea horse is the sole animal known to man which the male of the species endures the privilege of childbirth. Following a length courtship, a male and female have intercourse during which the female enters the male and lays as many as 200 eggs which are fertilized within the body of the male. After a 5-week gestation period, the male gives birth.”