One of the more interesting aspects of the underwater world is that there are many different kinds of reproduction. Fish change sex, nudibranchs don’t have a sex, and certain male fish get pregnant! One of the more visually stunning examples of reproduction among fish populations is the mouth brooding cardinal fish family. Typically the male cardinal fish is the one who “broods” the eggs in it’s mouth throughout the cycle from fertilization to hatching. During this time the fish does not eat, however, it does spit the eggs out of it’s mouth from time to time to aerate them. Cardinal fish are quite often found in large groups under and around coral heads and are frequently mating. Next time that you see a group of cardinal fish, have a look at their mouths closely to see if one of them is brooding a clutch of eggs.