Comparison of the Pectoral and Pelvic Skeletons and of some other Bones and their Phylogenetic Implications in the Aulorhynchidae and Gasterosteidae (Pisces)

Abstract

Study of the pectoral and pelvic skeletons and some other bones in recognized species of the seven genera comprising the related families Aulorhynchidae (tubesnouts) and Gasterosteidae (sticklebacks) showed that the two families differ in several respects, with no one living species appearing to be intermediate. The genera Aulorhynchus, Aulichthys, Spinachia, Apeltes, and Gasterosteus each have distinctive characteristics not found in any other genus of the two families. Gasterosteus wheatlandi is the only species of the two families that lacks both the posttemporal and the supracleithrum. The interrelations of the genera form a mosaic pattern and there is no acceptable basis in the characters examined for postulating a phylogeny within the Gasterosteidae or for selecting a living species as being a primitive form or the most closely allied to the Aulorhynchidae.