[pallas523]

Some fish DO care for their babies, but most do not. Some fish that do: Betta fish-the father cares for developing fry by keeping them in a bubble nest- if they fall out, he scoops them into his mouth and spits them back in the nestCichlids - the female holds the eggs and fry in her mouth to keep them safe from predatorsBluegills - the father guards his nest of eggs from other males and allows the female to go off and eat and therefore be able to mate again soonerThe reason that many fish don't care for their young has to do with a theory in ecology called "r- selection". This basically means they optimize the possibility of passing on their genes to the next generation by having many many many babies, by reproducing often, and by not using valuable energy to care for the babies. The opposite is "k-selection" in which an organism has very few offspring, takes very good care of them, and doesn't have more babies until the last one is able to take care of itself. Humans are generally considered to be "k-selected."