Development of female Russian sturgeon (Acipenser gueldenstaedtii) and hybrid (Acipenser baerii х Acipenser gueldenstaedtii) gonads reared in net cages

Stanimir Bonev, Lyudmila Nikolova

Abstract: The study was conducted with female individuals of Russian Sturgeon at the age of five and seven years old and hybrid of Siberian and Russian Sturgeon at the same age in the spring and the same groups in the winter. In hybrids of both age groups, there was a significant increase in gonads during the growing season. At 5-year-old, ovarian height increased by 69.8% (p < 0.05); the girth by 68.0% (p < 0.05); area – almost three times (p < 0.001). At 7-year-old differences are: 32.8% (p < 0.05); 29.5% (p < 0.05); 2.3 times (p < 0.01). In the spring, in 10% of the studied hybrids, an onset of oocyte formation was found. In December, oocytes are very well seen in 30% of the studied fish. In 5-year-old Russian Sturgeon, the height of the ovary increased by 64.1% (p < 0.01); area 64.3% (p < 0.05); but the girth has practically not changed. In the 7-year-old Russian Sturgeon, the height of the ovary increased by 78.5% (p < 0.001), the girth by 28.9% (p < 0.001) and the area by 95.08%. (p < 0.01). The height of the hybrid ovary during the spring was higher compared to the Russian Sturgeon by 51.1% (p < 0.05) in the 5-year-old fish and by 71% (p < 0.001) in the 7-year-old. However, the ovary girth in the 5-year-old Russian Sturgeon has higher values than in the same age hybrid 13.6% (p < 0.05). There is no significant difference in ovarian girth and area in 7-year-old Russian Sturgeons and hybrids. A significant difference in area was found between Russian Sturgeon of different age, and in 7-year-old it was larger by 41.9% (p < 0.05). In winter with a 6-summer-old hybrid compared to Russian Sturgeon at the same age, the height of the ovary and its girth were higher 56.3% (p < 0.001) and 45.0% (p < 0.05) respectively, while at 8-summer-olds, at higher hybrid parameter values, the differences are not significant.

Keywords: gonads; sturgeon; ultrasound techniques

Date published: 2019-09-05