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101.
An investigation was accomplished to find the effects of different sizes as a social stress on physiological responses and growth performance of Siberian sturgeon. Juvenile Siberian sturgeon were separated into two sizes (860.88 ± 22.32 g as larger fish and 427.28 ± 2.97 g as smaller fish). Three treatments including large size (L), small size (S), and mixed size (M) were considered. There were equal numbers of large and small fish in the M treatment. Sampling was carried out at 1st week (as a short‐term sampling) and 8th week (as a long‐term sampling) of the experiment. At the end of each sampling, haematocrit, glucose, cholesterol, triglyceride, total protein, lactate, and cortisol were measured. All growth parameters and feed utilization in large fish were not affected in the M treatment compared with the L treatment and also small fish in the M treatment compared with the S treatment. The final biomass in the S treatment was significantly higher than those in the L and M treatments. Haematocrit, glucose, cholesterol, triglyceride, total protein, lactate, and cortisol in the 1st week showed no significant difference with different sizes. However, in the 8th week, only haematocrit increased (by time not size) in the S treatment. Fish in the M treatment in both sizes did not experience the stress condition. Larger and smaller sizes had a positive social interaction; therefore, different sizes of Siberian sturgeon can maintain together without decreasing growth rate and also adverse physiological responses. 相似文献
102.
Reproduction efficacy of sturgeon as donors of oocytes is regulated by hormones effects. It can influence the egg quality or larvae functions as rearing mediators for successful production. This study is conducted to evaluate the concentration of sex steroids, cortisol and thyroid hormones and distinguish the relationship of maternal hormones' correlation in Stellate sturgeon. The study followed the hormones fluctuations that could impress some egg quality information such as fertilization rate. Female breeders were injected with LHRHa2 for controlled propagation. Samples from blood, ovarian fluid and oocytes were obtained for hormonal and biochemical analysis. Our results showed that the concentrations of estradiol 17‐β and testosterone were significantly higher and lower in oocyte and the plasma, respectively. The level of plasma cortisol was significantly higher than in ovarian fluid and oocytes. The results showed elevation of triiodothyronine and thyroxine concentrations in oocytes, which were significantly different with plasma and ovarian fluid. Thyroxine concentration of plasma and ovarian fluid revealed a significant negative correlation. The mentioned parameters showed negative correlation with fertilization rate. The biochemical parameters (calcium, glucose, cholesterol and triglyceride) revealed significant differences in blood, ovarian fluid and oocytes. These results showed direct relations of fertilization rate with hormones level. Therefore, fertilization rate as egg quality index could be recommended as a relevant indicator of maternal transferring of hormones from blood and ovarian fluid to oocyte. 相似文献
103.
Defaee Somayeh Falahatkar Bahram Lavajoo Fatemeh Efatpanah Iraj 《Aquaculture International》2022,30(4):2197-2197
Aquaculture International - 相似文献