On the status of Atlantic sturgeon:: conspecificity of European Acipenser sturio and North American Acipenser oxyrinchus

The evidence for separate species status for the European sturgeon, Acipenser sturio, and the North American Atlantic sturgeon, A. oxyrinchus, is re-evaluated. We consider historical morphological descriptions, recent genetic evidence, features of life history and ecology, and also undertake anatomical and morphological measures on a large number of individuals from these two taxa. We conclude that the evidence to support separate species status for these two groups is not sufficient. We propose that they represent geographically separate, but continuously variable, populations of a single species, composed of 4 subspecies.