Physiological changes and reproductive performance of Sterlet sturgeon Acipenser ruthenus injected with thiamine

To evaluate the effects of thiamine on physiological changes and spawning performance of Sterlet sturgeon Acipenser ruthenus, 45 farmed female fish (698.6 +/- 8.9 g) were randomly distributed in 9 tanks (1000 L) and fed a diet with 1 g/kg of an anti-thiamine drug. This was provided for 5 months prior to spawning. Thiamine hydrochloride was intraperitoneally injected to fish at three different doses: 0 (T-0, as control), 5 (T-5) and 50 (T-50) mg/kg body weight at days 30, 90 and 150 after the experiment started. After five months, the results showed no significant differences in weight gain and hemoglobin level, but hematocrit significantly increased in T-5 group. There was no significant difference in glucose-6-phosphate dehydrogenase and estradiol-17 beta, but testosterone was significantly increased in the T-50 group. Total thiamine concentration in the eggs was significantly higher in T-50 than that detected in the control group. Fecundity and larval mortality at 6 day post hatch (dph) showed no significant differences among treatments, while the number of eggs per gram was significantly lower in T-0 than that observed in T-50. Larval weights at 1 (11.6 mg) and 6 (23.1 mg) dph and-larval lengths at 6 (15.6 mm) dph were significantly affected by the treatment with the highest level of thiamine injection (T-50). Diseases symptoms such as yolk sac deformation, erratic pattern of swimming, and loss of equilibrium were observed at 4 dph in T-0 and T-5 groups. The overall results revealed that thiamine injection has positive effects on reproductive performance in the sturgeon and the negative impacts of anti-thiamine in the offspring can be reduced by the injection of this vitamin to the broodstock. (C) 2017 Elsevier B.V. All rights reserved.