Comments: Closely related to, but specifically distinct from, Palearctic A. sturio (see Lee et al. 1980).
Two subspecies are recognized: A. o. oxyrinchus along the Atlantic coast and A. o. desotoi along the Gulf Coast (Page and Burr 1991). See Ong et al. (1996) for genetic data supporting the subspecific designations. MtDNA data reveal strong stock structure along both the North American Atlantic and Gulf coasts at the regional and, in some instances, population levels (Waldman and Wirgin 1998).
The original (and hence correct) spelling of the specific name is "oxyrinchus," not "oxyrhynchus." The latter name, though long in use, must therefore be replaced by the former (see Gilbert 1992:33).
Gene sequencing data of Birstein and DeSalle (1998) indicate that there are least three main clades within Acipenser: A. sturio - A. oxyrinchus, A. schrenckii - A. transmontanus, and all Ponto-Caspian species plus A. dabrysnus and A. brevirostrum.
Krieger et al. (2000) examined phylogenetic relationships of North American sturgeons based on mtDNA sequences and found that (1) nucleotide sequences for all four examined genes for the three Scaphirhynchus species were identical; (2) the two Acipenser oxyrinchus subspecies were very similar in sequence; (3) A. transmontanus and A. medirostris were sister taxa, as were A. fulvescens and A. brevirostrum (in constrast to Birstein and DeSalle 1998).