So whaddaya wanna do tonight?

And would sheep be an infinitely regressive plural?

Fish is the plural of a single species, e.g., three lake trout is three fish, fishes is used when the individual are of different species, e.g., a lake trout, a muskie and a rainbow trout would be three fishes. Naw, that doesn't taste right (thanks, xara, I like that phrase). Fishes is more generic. Lake trout, muskie and rainbow trout are three fishes