Seahorses break the rule in childcare. The male seahorse has a brood pouch. The female seahorse is the egg maker, and the male is the receptor. The male incubates the eggs until they become embryos. Females go on their merry way, and leave the male with all the work!
The male and female must court before breeding. It is a dance that lasts for several days. Without this dance, the male would not be able to receive the female eggs.
While courting, the male and female entwine tails, change colors and swim around each other in synchronous matching. The male makes clicking noises with his skull.
The female has a tendency to become bored or distracted and the male snaps at her head to bring her attention back to the purpose of the dance. Researchers call this the “pre-dawn dance”. The male and female begin dancing in earnest. The male seahorse signals the female that he is ready by pumping water into his brood pouch to show the female that it is empty and ready for eggs. When the eggs mature, the mates entwine their tails and slowly float and spin together to the surface of the water. As they entwine and float to the surface, the couple align themselves. The female has a tube (ovipositor), which she inserts into the male's pouch. The eggs travel through the tube and fill the pouch. The male seahorse sinks to the bottom of the sea, releases his sperm into the water. This fertilizes the eggs. He is the caretaker of the now fertilized eggs.
After egg fertilization, the eggs became embedded in the pouch wall and covered with tissue. This tissue serves as a placenta in feeding the eggs, provides oxygen, as well as a safe incubator. The eggs hatch inside the pouch. The male slowly adds sea water to prepare the eggs for life outside of the pouch. Gestation lasts 40 to 50 days. The female returns every day to perform the spinning and floating to the surface dance with the male. This helps the bonding of the couple. She leaves right after the dance.
The eggs hatch and the male seahorse goes into labor. This lasts for several hours. The baby seahorses (fry) are pushed out with muscular contractions similar to mammals. After all the time spent with the eggs and the contractions of labor, the seahorse provides no parental care of the miniature fry. Most fry does not survive. Many predators eat them. Some fry are deposited in an area with little food. They do not survive. This is the reason the female deposits so many eggs in the pouch.