Male seahorses are the ones that get pregnant and can give birth to 2,000 babies at once.

Seahorses belong to a group called Hippocampus and they are very rare because the males handle the pregnancy. The dad's pouch is called a marsupium. It does a lot more than just hold eggs. He actually controls the salt levels in the pouch so the babies are ready for the ocean water when they are born.The pregnancy usually lasts between 10 and 25 days. During this time, the dad's body sends fats and calcium to the babies to help them grow strong bones and bodies. Scientists found that a hormone called prolactin helps the dad manage the pregnancy. This is the same hormone that helps human mothers produce milk for their babies.When the babies are ready, the dad's muscles squeeze to push the tiny seahorses, called fry, into the ocean. While he can have up to 2,000 babies, only about 1 out of every 200 survives to become an adult. Because the dad is busy carrying the babies, the mom can focus on making more eggs right away. This team effort helps seahorses have as many children as possible in a short time.