The molecular phylogeny of the order Acipenseriformes revisited

Abstract

As evolutionary relationships within the order Acipenseriformes are not well understood and some classifications are currently controversial, the study of evolutionary relationships, especially based on genetic data, has received much recent attention. In this reanalysis we present a nearly complete proposed phylogeny of the order, including 25 species, based on the maximum likelihood analysis of combined DNA sequence data (4406 base pairs) from five mitochondrial genes sequenced in our laboratories (cytochrome b, 12S rRNA, cytochrome c oxidase subunit II, tRNA Asp and tRNA Phe ) and three mitochondrial gene regions sequenced by Birstein et al. (2002) (16S rRNA, NADH5 and control region). Examination of the molecular phylogeny using either maximum likelihood, Bayesian analysis, maximum parsimony or neighbor-joining leads to the following conclusions: (i) the two species of paddlefish do form a clade; (ii) the most basal position within the Acipenseridae remains unresolved, held either by the genus Scaphirhynchus or by the clade containing Acipenser oxyrinchus and A. sturio; (iii) Huso is not monophyletic, with the two species of Huso found embedded separately within the genus Acipenser; (iv) A. sinensis and A. dabryanus are confirmed as closely related; (v) the previously described Atlantic-Pacific subdivision within the Acipenser ⁄ Huso complex is supported and (vi) the unexpected placement of Pseudoscaphirhynchus kaufmanni within Acipenser is supported by this analysis. These results offer further evidence that some revision of acipenseriform classification may be needed to accurately inform conservation efforts and that future phylogenetic studies of this group should focus on the analysis of nuclear genes.

The karyotype of the Amu Darya sturgeon, Pseudoscaphirhynchus kaufmanni (Actinopterygii: Acipenseriformes: Acipenseridae)

“…1); thereby, karyological data does not support close relation between Scaphirhynchus and Pseudoscaphirhynchus postulated by morphological studies and resulted in their accepted taxonomic integration in the same tribe or subfamily. The same results were obtained by molecular genetic researches, not supported sister relation between Scaphirhynchus and Pseudoscaphirhynchus, but demonstrated Pseudoscaphirhynchus as a sister taxon for the genus Acipenser (see Birstein et al 1997) or for some of Acipenser species (Dillman et al 2007, Krieger et al 2008). …”

“…Another taxonomic hypothesis accepts Scaphirhynchinae as a separate subfamily opposed to all other Acipenserids (Berg 1905, Sokolov andBerdichevskiĭ 1989). Both of these taxonomic concepts do not agree with recent molecular data (Ludwig et al 2001, Dillman et al 2007, Krieger et al 2008.…”

“…All karyotyped Acipenserids are divided into three discrete groups. The first group includes 120-chromosome species (Table 1 trees based on molecular genetic data (Ludwig et al 2001, Krieger et al 2008. The third group includes the only species Acipenser brevirostrum Lesueur, 1818 with 370-372 chromosomes (Kim et al 2005, Fontana et al 2008a).…”

Low Danube Sturgeon Identification Using DNA Markers

“…The American Atlantic sturgeon (A. oxyrhinchus) and the common European Atlantic sturgeon (A. sturio) form a monophyletic group and occupy a basal position in the Acipenseridae family. This conclusion confirms other molecular phylogeny studies (Krieger et al, 2008), but it is in contradiction with morphometric data, which places in a basal position the group formed by the species of the Scaphirhynchus genus (Mayden & Kuhajda, 1996;Birstein & DeSalle, 1998). Within the trees obtained, in the Acipenseridae family, two major clades were observed: the Atlantic clade (A. ruthenus, A. nudiventris, A. stellatus, A. fulvescens, A. brevirostrum, A. baerii, A. persicus, A. gueldenstaedtii, A. naccarii and H. huso) and the Pacific clade (A. sinensis, A. dabryanus, A. medirostris, A. mikadoi, A. transmontanus, A. schrenckii and H. dauricus).…”

Complete mitochondrial genomes of the critically endangered Ship sturgeon Acipenser nudiventris from two seas

“…Ship sturgeon clusters with A. ruthenus, as it was shown in Peng et al (2007), but A. nudiventris-A. ruthenus branch is not a sister clade to A. stellatus as it was found previously (Peng et al 2007;Krieger et al 2008), but has a common ancestor with high chromosome number Ponto-Caspian species such as A. gueldenstaedtii and A. baerii. High similarity between ship sturgeon mitogenome sequences from two geographically isolated sea basins indicates that Aral and Caspian seas were connected in the recent past.…”