Several Ecological Features of the Distribution of Russian Sturgeon Acipenser güldenstädti and Stellate Sturgeon Acipenser stellatus in the Sea of Azov

The distribution of Russian sturgeon Acipenser güldenstädti and stellate sturgeon Acipenser stellatus in the Sea of Azov was studied. In March, 1993, the highest population density of the Russian sturgeon was detected in the southwestern, central, and south regions of the sea. The highest number of fishes captured per trawling sample was 149. The distribution of stellate sturgeon was similar, and a high population density was observed in the same regions. The highest density corresponded to 121 fishes per trawling sample. A high proportion of young fishes was characteristic of both species in summer. Thus 112 out of 140 Russian sturgeon fishes and 32 out of 112 stellate sturgeon fishes were young. Nonuniform distribution of the nutritive base was assumed to be a possible cause of the nonuniform distribution of sturgeon species.