Comparative growth of juvenile sterlet (Acipenser ruthenus) and Siberian sturgeon (A-baerii) under identical experimental conditions

Growth of 0+juveniles of the sterlet (Acipenser ruthenus) and the Siberian sturgeon (A. baerii) was studied under experimental condition from 15 May to 29 August 1996. In sterlet, the initial total length (TL) at the start of trial was 170.9 mm, and the final one after 107 days was 300.7 mm. Corresponding daily increments (DI) in sterlet's TL ranged 0.65-1.62 mm.d(-1), the specific length growth rate (SLGR) decreased successively from 0.69 to 0.38%, daily increments of body weight ranged 0.40-1.47 g.d(-1), specific weight growth rate (SWGR) values 0.97-3.77%. The following Values were found in the Siberian sturgeon: initial and final TL 153.5 and 378.3 mm, range of daily increment (DI) in TL 0.18-2.69 mm.d(-1), SLGR 0.12-0.13%, range of DI in body weight 0.73-3.14 g.d(-1), range of SWGR values 2.05-6.06%. In addition, data are also presented on development of daily feeding ratio, feed conversion rate, Fulton's condition factor, length-weight relationship, mortality and behaviour. The results concerning the growth rate of both species document their extraordinary growth potencial during the first year of life, as well as their possible joint rearing in aquaculture.