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

Cranial morphology of the Stellate Sturgeon, Acipenser stellatus Pallas 1771 (Acipenseriformes, Acipenseridae), with notes on the skulls of other sturgeons

“…The Stellate Sturgeon, Acipenser stellatus Pallas, 1771 (Figure 1), is a relatively small species of sturgeon, with a maximum known size of 218 cm total length and a weight of 54 kg (Borzenko, 1942, cited in Shubina et al., 1989). Acipenser stellatus , together with other species of sturgeons such as H. huso , A. ruthenus , A. sturio , S. platorhynchus and Pseudoscaphirhynchus kaufmanni , is a member of the so‐called 120‐chromosome group of sturgeons (Group A of Fontana, 2002; see also Kovalev et al., 2014 for P. kaufmanni ), with a karyotype of 2 n = 146 ± 6; 37 pairs of meta‐submetacentric chromosomes, the balance are acrocentrics and microchromosomes (Chicca et al., 2002; see also Birstein and Vasil'ev, 1987, Suciu & Ene, 1996, and Nowruzfashkhami & Khosroshahi, 1999, who estimated different numbers of chromosomes in this species using different methodologies). Acipenser stellatus is anadromous and occurs throughout the Black, Agean, Caspian, and Asov seas and the major tributaries of these waters; introductions were made also to the Aral Sea but these appear to be unsuccessful (Shubina et al.…”