Evolution and Biogeography of the Clinidae (Teleostei: Blennioidei)

Abstract

The systematic and biogeographic relationships of the teleost family Clinidae (commonly known as kelpfishes or klipfishes), an antitropically distributed group of nearshore fishes characterized by widespread ecological variation, were analyzed using allozyme and morphological characters. The Clinidae comprises three tribes; the matritrophic (ovoviviparous) Clinini and Ophiclinini, and the oviparous tribe Myxodini. Emphasis of the present study was in resolving the relationships among the eastern Pacific Myxodini, which include the South American genus Myxodes and the North American genera Heterostichus and Gibbonsia. Allozyme data were analyzed from 40 presumptive gene loci for all four North American myxodin species, one species of the Australian clinid tribe Clinini (Heteroclinus whiteleggei), 10 species (representing all tribes) of the hypothesized sister blennioid family, the Labrisomidae, and two species of the blennioid family Chaenopsidae (also believed to be closely related; the latter two families were used as outgroups). Several different phylogenetic approaches for analyzing allozyme data were used for purposes of comparison, including two frequency character methods, a genetic distance method, a discrete character parsimony method (using only fixed alleles), and a multistate character parsimony analysis (the latter two used presumptive gene loci as characters and selected alleles as character states). Discrete morphological characters were also analyzed both separately and included with allozyme data in parsimony analyses. Results from morphological and allozyme data, as well as the different methods of phylogenetic analysis, were congruent; yielding identical parsimonious relationships among taxa, except within the genus Gibbonsia. Two most parsimonious trees were consistently obtained, which differ in whether G. metzi or G. elegans is the basal clade within the genus (and the sister group to the other two species). The Clinidae is distinguished by a suite of allozyme character state synapomorphies identified in the present study as well as three morphological synapomorphies. The present study indicates that the cryptotremin labrisomids are the sister group to the Clinidae. The trophodermic matritrophic (ovoviviparous) clinids (comprising the tribes Clinini and Ophiclinini) and the Myxodini are sister taxa, and the South American myxodin genus Myxodes is sister to the northern myxodin genera. The North American genera Heterostichus and Gibbonsia are sister groups.