Phylogeny of the family Congrogadidae (Pisces; Perciformes) and its placement as a subfamily of the Pseudochromidae

A study of the osteology, myology and selected external characters of the Congrogadidae elucidates the phylogenetic relationships of as many taxa as were available for examination. Character polarity was determined using the outgroup method. Evidence is presented to support the hypotheses that (a) congrogadids and pseudochromids form a monophyletic group; (b) anisochromins and congrogadids are sister groups; and (c) the sister group of this latter assemblage is the Pseudoplesiopinae. Utilizing the anisochromins and pseudoplesiopins as outgroups, it is hypothesized that the relationships of the genera of congrogadids can be expressed as follows, using the sequencing convention: Rusichthys, the halimuraenoid, Haliophis, Halidesmus, Natalichthys, Blennodesmus, Halimuraena, Congrogadus and Congrogadoides. Autapomorphies supporting the hypothesized monophyly of each of the genera Congrogadus, Congrogadoides and Halidesmus are presented, but only in the case of Halidesmus could we postulate the relationships of the contained species. We were unable to identify autapomorphies for the three species contained in each of Natalichthys and Halimuraena. The genera Congrogadus and Congrogadoides, with a total of five species between them, share eight specializations, and form a monophyletic group. In view of this, we reduce Congrogadoides to a subgenus of Congrogadus.

To preserve the monophyletic integrity of the Pseudochromidae, we reduce the Congrogadidae to subfamilial status within the Pseudochromidae, thus ending their long tenure among the blennioid fishes.