Comparative myology of the unicornfishes, Naso (Acanthuridae, Percomorpha), with implications for phylogenetic...

Striated muscles of 15 species of unicornfishes (Naso, Acanthuridae) are described in detail. Of 93 muscles dissected, only five demonstrate intrageneric variation, providing only ten characters suitable for phylogenetic analysis. Thus, myology appears to be highly conservative at the species level and has been so for approximately 50-55 million years in this particular group of fishes. Furthermore, myology is static relative to osteology in Naso and at any taxonomic rank within fishes, implying osteology provides a larger but not necessarily more valuable data source for systematic studies. Although important for their epistomological value, these descriptions provide a basis for further studies ranging from functional, comparative, and systematic analyses, ultimately with the potential to address questions of historical ecology (i.e., speciation, adaptation, coevolution) within Naso. J. Morphol. 239:191-224, 1999. © 1999 Wiley-Liss, Inc.