Fish don't normally mate. The female lays eggs and swims away, the male then fertilizes the eggs. In some species they'll keep watch over their nest, others don't. Now... that said, one of the real miracles of nature comes in the form of a fish... The seahorse. They are a beauty to behold. Their courtship rituals are amazing, absolutely beautiful. The pair will swim around together, holding one each others tails. They dance for one another too. When they are ready, the male puffs out his pouch, and the female deposits her eggs inside.