Sturgeon Phylogeny: A Full Mitogenomic Approach

The study of sturgeon evolutionary history began fairly recently, and many questions about these fishes and their evolution are still unanswered.  Sturgeons have traditionally been classified in four genera (Acipenser, Huso, Scaphirhynchus, and Pseudoscaphirhynchus), with morphological studies recovering Huso as basal to and separate from the other three genera. Scaphirhynchus and Pseudoscaphirhynchus have been considered sister genera.  Recent studies using morphological and newly available molecular data have suggested different arrangements of the sturgeon family tree, generally proposing the collapse of the genus Huso into Acipenser and classifying Pseudoscaphirhynchus as sister to Acipenser.  Despite these broad trends across studies, the details of phylogenetic relationships (ie sister species configurations) vary from study to study, leaving sturgeon phylogeny unresolved.  Previous studies have been limited to the use of various fragments of mitochondrion, rather than the full mitochondrion, to elucidate evolutionary relationships among sturgeons.  In an effort to help resolve conflicting hypotheses among previous studies, we introduce novel data in the form of complete mitogenomic sequences (16,000 base pairs) of >20 sturgeon species.  We present a phylogenetic hypothesis based on these sequences, discuss the implications of the proposed relationships, and briefly discuss potential applications of these new data to conservation efforts.