Commercially available probiotic enhanced growth, digestion and immune response of Rohu (Labeo rohita) reared in earthen pond

The use of Probiotics in aquaculture got an importance in the previous years. Hence, present study was carried out to evaluate the effects of the commercially available dietary probiotic (a consortium of Bacillus subtilis and Saccharomyces cerevisiae) on the growth, proximate body composition, digestive enzymes, hematological parameters and immune response of rohu (Labeo rohita) in a polyculture system. Fingerlings with average body weight and length of 11.00 ± 2.34 g and 9.50 ± 5.50 cm, respectively, were stocked in 6 earthen ponds, at the rate of 200 fingerlings/pond making a total of 1200 fingerlings. The experiment was extended for 3 months in two groups i.e. probiotics treated and control groups. After three months feeding trial glucose, aspartate aminotransferase (AST), moisture content, ash contents and feed conversion rate (FCR) were significantly decreased in the probiotics supplemented group. At the same time point, Hb, MCH, HCT, total protein, plasma protein, lipid contents, final body mass and final body weight, percent weight gain, cellulase activity, protease activity and amylase activity and white blood corpuscles were significantly increased in the probiotics supplemented group. In conclusion, the use of probiotic enhanced growth, digestive enzyme activities and immune response of L. rohita in a polyculture system

Potential Contributions of miR-200a/-200b and Their Target Gene–Leptin to the Sexual Size Dimorphism in Yellow Catfish

Sexual size dimorphism is the consequence of differential expression of sex-biased genes related to feeding and growth. Leptin is known to regulate energy balance by regulating food intake. In order to investigate the molecular mechanism of sexual size dimorphism in yellow catfish (Pelteobagrus fulvidraco), the expression of leptin (lep) and its functional receptor (lepr) were detected during larval development. Both lep and lepr have lower expression in males than in females during 1–4 weeks post hatching. 17a-Methyltestosterone (MT) treatment resulted in decreased expression of lep and lepr in both male and female larval fish. Interestingly, the mRNA levels of lep and lepr in juvenile male were significantly decreased compared with juvenile female during short-term fasting periods. Lep was predicted to be a potential target of miR-200a and miR-200b that had an opposite expression pattern to lep in male and female larvas. The results of luciferase reporter assay suggested that lep is a target of miR-200a/-200b. Subsequently, male hormone and fasting treatment have opposite effects on the expression of miR-200a/-200b and lep between males and females. In summary, our results suggest that sexual size dimorphism in fish species is probably caused by the sexually dimorphic expression of leptin, which could be negatively regulated by miR-200a/-200b