Abstract
The gut patterns of one or more species of all six genera of the family Acanthuridae, and of the single genus of the family Zanclidae, are described and the phylogenetic significance of the patterns is considered.An advanced pattern, placement of the end of the b loop to the left side of the stomach, is shared by Zanclidae and all acanthurids, suggesting that they are a monophyletic group.The gut patterns of the acanthurids contain little intrafamilial phylogenetic information.
