He ate the starfish and the garfish, and the crab and the dab, and the plaice and the dace, and the skate and his mate, and the mackereel and the pickereel, and the really truly twirly-whirly eel.
A dace is a small fish that can be one of many different species. The unmodified name is usually a reference to the common dace (Leuciscus leuciscus). This, like most fishes called "daces", belongs to the family Cyprinidae, mostly in subfamily Leuciscinae.