Comparative osteology and relationships of the Umbridae (Pisces: Salmoniformes)

Abstract

The phylogenetic relationships of the five living species of umbrids are examined through a comparative osteological study based on a series of cleared-and-stained specimens of each species. The Umbridae appear to be strictly monophyletic. In addition, for 45 characters, the outgroup Esox shares one character-state with at least one umbrid species, while two or more umbrid species share the other state. Assuming that the states shared with Esox are primitive for the Umbridae, the hypothesis that Dallia is more closely related to Umbra than to Novumbra is supported by compatibility and Wagner-tree analysis of the data. Thirteen derived characters are shared by Dallia and Umbra, 20 more are shared by the three species of Umbra, and four more by U. limi and U. pygmaea. Eight characters are considered likely to have undergone reversal or parallel evolution.