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This study aimed to evaluate the effect of vitamin E on the reproductive responses and the expression of reproductive genes in butter catfish (Ompok bimaculatus). Diets with different levels of vitamin E supplementation (0, 100, and 150 mg/kg) were provided to groups of fish for 60 days. After rearing for 60 days fish were induced with synthetic hormone, that is, Ovatide to study the breeding performance. Ovatide was administrated intramuscularly at the rate of 0.5 and 0.25 mL/kg of body weight for females and males, respectively, in all the treatments. Breeding performance result shows that supplements of vitamin E positively influenced the GSI%, fertilization rate, fecundity, and hatching rate. To understand the relationship between vitamin E and the breeding performance of the fish at the molecular level, a gene expression study was conducted. This study employed real‐time PCR for the selected genes critical for reproductive function. In the brain, testis, and ovary dietary vitamin E supplementation of 100 mg/kg significantly enhanced the mRNA transcription of FSHR, Brdt, ESR1, 17beta2, and LHR. Hence, it can be said that 100 mg/kg of vitamin E supplementation in the diet during the reproductive period of O. bimaculatus could improve breeding performance and the mRNA expression of reproductive hormone receptor genes in both males and females of O. bimaculatus. [ABSTRACT FROM AUTHOR]

Fish pigmentation study can reveal understandings in dermatological research based on functional genomics. Cultured ornamental fish becomes dull coloured and antityrosinase activity through sesame seed may enhance skin colour, which has not been studied. Botia dario is an indigenous fish, having ornamental and aesthetic value and can be studied as a model for fish pigmentation genetics. In this study, fish specimens were fed with 15% marigold petal meal along with 5, 10 and 15% w/w sesame seed in diet. Pigmentation genes, that is, tyr, tyrp1a, asip1, gnaq, kitlga, mc1r, mitf, pax7a, rab38, slc7a11, sox9a, sox10, csf1r, bcdo2 and gsta2 in skin and immunogens, that is, il20, nramp, tlr9 and trail in kidney were studied. Gene expression in tissues revealed enhanced pigmentation and immunity as well as the role of tyr, tyrp1a and asip1 in pigmentation. Immunogenes and blood parameters confirmed the best pigmentation diet. Colorimetric analysis also showed the enhancement of pigmentation. Insights from sesame seed and marigold‐induced antityrosinase effects will be applied in aquaculture to develop natural, dietary formulations that will enhance pigmentation in ornamental fish, leading to improved skin colour and market value. [ABSTRACT FROM AUTHOR]

An experiment was designed to evaluate the requirement of dietary protein for Reba carp, Cirrhinus reba fingerlings using semi‐purified diet. Five isocaloric diets were prepared containing 20%, 25%, 30%, 35% and 40% level of protein using casein, gelatin as a major protein source. The experiment was conducted for 105 days in triplicates to evaluate the growth, survival, feed utilization, carcass composition of C. reba. Mean weight gain was highest (p < .05) in T3. Specific growth rate was highest in T3 and lowest in T1. Similarly, significantly (p < .05) highest net fish yield were recorded in T3. No significant difference was recorded in survivability. Feed conversion ratio, protein efficiency ratio, feed conversion efficiency and protein conversion efficiency were significantly (p < .05) higher for T3 compared with other treatments. Highest carcass protein and lipid values were recorded in T3. So, conclusion can be drawn that 30% crude protein is optimum for overall performance. Furthermore, broken‐line analysis for specific growth rate, final biomass and net fish yield indicated that dietary protein level of 28.148 to 28.253% is optimum for the best growth performance of fingerling C. reba. [ABSTRACT FROM AUTHOR]