RELATIONSHIPS AND BIOGEOGRAPHY OF THE FOSSIL AND LIVING AFRICAN SNAKEHEAD FISHES (PERCOMORPHA, CHANNIDAE, PARACHANNA)

The ability to determine relationships of Cenozoic fossil fishes relies heavily on having osteological information from their extant relatives with which to compare the fossil remains. For many higher teleost fishes, these osteological data do not exist. For example, dagger Parachanna fayumensis, from Eocene and Oligocene deposits of Egypt, was placed in the Recent snakehead genus Parachanna, but in the absence of data from extant members of the genus, this hypothesis could not be tested. Three other fossil channids were each given their own new genera, without an analysis of their relationships to one another or to the living genera. In order to properly test the relationships of these fossil species, the osteological information for living species is needed. This paper documents the osteology of the African snakehead, Parachanna obscura, for the first time. The documentation of the osteology forms the basis of a phylogenetic study of the relationships of the African fossil, dagger Parachanna fayumensis, with living African snakeheads. This study supports the generic placement of dagger P. fayumensis as being correct, as well as reciprocal monophyly of the two living snakehead genera and monophyly of the family. Monophyly of the Asian genus Channa and the relationships of the other fossil species need to be further assessed using a broader range of species, but this preliminary study is an essential first step. Apomorphic osteological characters are given for the family and genera, as well as a discussion of the biogeographical relationships of species of Parachanna.