Comparative analysis of morphometric characters of juvenile sterlet Acipenser ruthenus L. from natural population and aquaculture

Abstract

A comparative analysis was performed on sixteen morphometric characters, in three different juvenile sterlet Acipenser ruthenus L. populations. Specimens were collected from a wild population in the Serbian part of the Danube River (n = 46), from aquaculture stocks in the Czech Republic originating from Russia (n = 40), and aquaculture stocks in the Slovak Republic originating from Slovakian part of the Danube River (n = 28). Average values for total length were 29·9 ± 3·9 cm, 29·1 ± 3·7 cm and 27·3 ± 7·7 cm for Serbia, Czech Republic and Slovak Republic, respectively. Populations were compared using t‐test and sequential Bonferroni correction for multiple comparisons was applied in order to determine significant differences between them. Results of analysis showed that all three populations differed in prebarbel length, interocular distance and maximum head width. Although all these characters are head‐related, head length itself was very uniform among all populations. The natural population from the Serbian part of the Danube River differed from the populations reared in aquaculture in seven morphometric characters. The two populations reared in aquaculture consistently showed lower morphological variability than the wild population, even though they had different genetic backgrounds (Russia and Slovakia). Future genetic studies will show if this tendency is caused by a reduction in genetic variability.