some says… 

Think about this for a moment. In the animal kingdom it is mostly the male that competes against other males for a female partner. For example, many male birds have bright colours and fancy plumage to attract a female partner. Males in some other groups have large tusks or horns to show strength and their ability to protect the female and her young.

Now in the seahorse world, things are a little different…..well so we thought. Since it is the male that becomes pregnant and gives birth to the live baby seahorses, it would seem logical that the female seahorses compete amongst themselves for male partners to care for their eggs. Well, that is what we thought. However, research has shown that it is STILL the males that compete for females. When male seahorses want to impress a female, they have tail pulling competitions, dragging each other around on the bottom of the seabed. They also snap at each other with their snouts and wrestle with each other using their long curved necks. They also display their pouches to the prospective female by opening and closing them, filling their pouches with water and expelling it with force, to show the fitness of the pouch for the birth process.

Not quite Ripliey’s but something to think about.

The male will eat food that happens to be in the area while the female will roam about in search of food. Regardless of this separation however, the female will always come back to the male to perform their daily ritual of entwining their tails and spiralling to the surface in a dance of celebration.
This ritual helps keep the pair synchronized reproductively. If a mate is removed or dies, it will take weeks to find a new mate, that is, if it is able to at all!

They give birth but they don’t lay eggs, they’re just taking good care of the egg of the female seahorses by keeping it in the pouch of a male seahorse.

[full source]