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Not AvailableThe present study was undertaken to gain insight on the physiological basis underlying the constraints in attaining maturity of endangered golden mahseer (Tor putitora) in captivity. Selected hormone levels and stress biomarkers were analysed in wild and captive reared brooders to address the above objectives. As compared to their captive counterparts, plasma 17β-estradiol was significantly (p < 0.05) higher in wild caught females. A concurrent trend was observed for plasma vitellogenin, aromatase, 17α, 20β-dihydroxy progesterone (17α, 20β DHP), luteinizing hormone (LH) and11-ketotestosterone (11-KT) indicating a weak hormone response in captive females that potentially hindered maturity. To the contrary, the plasma11-KT levels were not significantly different between wild and captive males. Plasma 17α, 20β DHP level was found significantly (p < 0.05) higher in wild caught females compared to females reared in captivity. However, both males of wild and captivity registered significantly higher 17α, 20β DHP than captive females. Plasma 11-KT level was significantly higher in males compared to females. However, the captive females had higher level of 11-KT than captive males. Stress biomarkers viz., cortisol, superoxide dismutase (SOD) and glutathione peroxidase (GPx) were also estimated both in wild and captive brooders. There was no significant difference in plasma cortisol levels of wild and captive reared brooders. However, plasma GPx and SOD activity were significantly higher in captive reared T. putitora as compared to wild brooders counterpart manifesting prevailing oxidative stress in captivity. Overall results showed endocrine and stress differences between wild and captive reared brood fishes during early spawning period which highlighted the endocrine failure of female reproductive maturity in captivity.Not Availabl

Higher acclimation temperature modulates the composition of muscle fatty acid of Tor putitora juveniles

A 30-day acclimation trial was conducted using golden mahseer, Tor putitora juveniles to study its muscle fatty acid composition at five acclimation temperatures (AT). Ninety juveniles of T. putitora were distributed among five treatment groups (20, 23, 26, 29 and 32±0.5 °C). At the end of 30 days trial, highest percentage of monounsaturated fatty acids was found at 20 °C and lowest at 26 °C. The highest percentage of n-6 polyunsaturated fatty acid (PUFA) was found at 23 °C and a decreasing trend was observed with increase in AT. However, highest percentage of n-3 PUFA was found at 32 °C and lowest at 29 °C. The maximum n-6 to n-3 ratio was observed at 23 °C and ratio decreased to a minimum at 32 °C. The results revealed that T. putitora juveniles could adapt to higher acclimation temperatures by altering its muscle fatty acid composition mainly by increasing its total saturated fatty acids especially stearic acid

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Not AvailableAn experiment was conducted to study the effect of sub-lethal nitrite exposure on sex steroids (testosterone and estradiol), cortisol and thyroid hormones (T3 and T4) of Labeo rohita juveniles. Fishes previously fed with normal or elevated levels of vitamin E (VE) and tryptophan for 60 dayswere exposed to sublethal nitrite for another 45 days with same feeding regime. There were nine treatment groups, viz. VE0TRP0-N, VE0TRP0?N, VE100TRP0-N, VE100 TRP0?N, VE100TRP0.75?N, VE100TRP1.5?N, VE150 TRP0?N, VE300TRP0?N and VE200TRP1?N. Except the groups VE0TRP0-N and VE100TRP0-N, all other groups were exposed to nitrite.At the end of the 45 days of nitrite exposure, serum samples were assayed for sex steroids, cortisol and thyroid hormones. The serum T3 and T4 levels decreased to the extent of 84.5 and 94.06 %, respectively, upon nitrite exposure. Dietary supplementation with additional amounts of VE and tryptophan appears to reduce the decline of the production of T4. The serum testosterone and estradiol decreased 97.31 and 92.86 %, respectively, upon nitrite exposure. Supplementation with additional amounts of VE was found to reverse nitrite-induced inhibition of testosterone and estradiol production. Serum cortisol increased upon nitrite exposure and unexposed (VE100- N) group showed lower levels, which were comparable to groups fed with elevated levels of VE. The overall results of the present study revealed that environmental nitrites have a negative impact on steroidogenesis, which can be overcome by dietary supplementation of elevated amounts of VE (minimum of 150 mg VE Kg diet-1) and to a lesser extent by tryptophan (only at the level of 1.5 % of the diet).Not Availabl

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Not AvailableA 30-day acclimation trial was conducted using Tor putitora to elucidate its thermal tolerance, oxygen consumption, haemato-biochemical variables and selected enzymatic activities at five acclimation temperatures (AT). Juveniles of T. putitora were randomly distributed among five treatment groups (20, 23, 26, 29 and 32 ± 0.5 _C). There was a significant curvilinear increase in critical thermal maxima (CTmax) (y = -0.0693x2 ? 1.7927x ? 34.628, R2 = 0.996) and lethal thermal maxima (LTmax) (y = -0.1493x2 ? 2.3407x ? 35.092, R2 = 0.991) with increasing AT. The oxygen consumption rate increased significantly with increasing AT. The Q10 values were 1.16 between 20 and 23 _C, 3.09 between 23 and 26 _C, 1.31 between 26 and 29 _C and 1.76 between 29 and 32 _C of AT. The acclimation response ratios were ranged between 0.37 and 0.59. Catalase, superoxide dismutase and ATPase activities were increased linearly in liver, gill and kidney, while brain acetylcholine esterase activity decreased linearly with increasing AT. Blood glucose remained unchanged up to AT of 26 _C and increased significantly at AT of 29 and 32 _C. Haemoglobin content was increased linearly with increasing AT. The highest WBC count was observed at 20 _C, and no significant changes found till AT of 26 _C and significantly decreased at 32 _C. Total serum protein and globulin were significantly decreased with increasing AT. Highest values were observed at 20 _C and remained consistent till 26 _C, then decreased significantly. There was no significant change in A/G ratio through the AT 20–29 _C and increased significantly at 32 _C. The increase in CTmax, LTmax and oxygen consumption rate with increasing AT may suggest that the thermal tolerance of T. putitora is dependent on its prior thermal exposure history, and it could adapt to higher AT by altering its haemato-biochemical variables.Not Availabl

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Not AvailableIn the present investigation, the Labeo rohita juveniles that were previously fed with vitamin E and tryptophan supplemented diet for 60 days were exposed to sub-lethal concentration of nitrite-nitrogen (2.0 mg/l) for the next 45 days with the same feeding regime. After 45 days of nitrite exposure, nitrite was withdrawn and the fishes were again fed with their respective diets for the next 60 days. After this period, the different treatment groups were challenged with Aeromonas hydrophila to study the degree of immunosuppression caused by nitrite and the efficacy of vitamin E and tryptophan in improving the fish health and survival. From the results obtained in the present study, it could be concluded that the enhanced non-specific resistance factors viz., NBT, lysozyme activity, and WBC count observed in the high vitamin E and tryptophan diet fed groups compared with control upon challenge with A. hydrophila clearly revealed the role of these two additives in boosting non-specific immunity in rohu. Moreover, the survival percentage of nitrite induced immunocompromised L. rohita was also improved by feeding elevated amounts of vitamin E and tryptophan in the diet.Not Availabl

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Not AvailableUltrastructural and histological changes in the embryonic and larval surface during ontogenesis of the endangered golden mahseer Tor putitora is studied here for the first time. Embryonic development was completed 91-92 h after fertilization at an ambient temperature of 23° ± 1° C (mean ± s.d.). The gastrula stage was characterized by presence of the Kupffer's vesicle, notochord, ectoderm and endoderm cells. Primordial germ cells were clearly identifiable from c. 55 h post-fertilization at the organogenesis stage. Mean total length of newly hatched larvae was 7•0 ± 0•5 mm. Scanning electron microscopy of newly hatched larvae demonstrated vitelline arteries, microridged epithelial cells and mucous gland openings over much of the body surface. Eye, oral cavity, pharyngeal arches, heart, intestinal loop, prosencephalon, cephalic vesicle and nasal epithelium were clearly distinguished in 3 day old hatched individuals. In 6 day old individuals, caudal-fin rays and internal organs were evident. The dorsal fin became prominent at this stage and larvae began swimming at the surface. The reserved yolk material was totally absorbed 8-11 days after hatching and larvae began feeding exogenously. Tor putitora exhibited a longer early developmental period than other cyprinids reared at similar temperatures.Indian Council of Agricultural Research (ICAR

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Not AvailableThe present study was conducted to determine fatty acid profile, amino acid and mineral content of rainbow trout fromIndian Himalayan region. The crude protein, crude fat and ash content were 19.44, 5.18 and 1.37% respectively. Proteinhad a well-balanced amino acid composition, with higher amounts of proline. The highest amino acid score was observed fortryptophan followed by isoleucine. Total monounsaturated fatty acids were high followed by saturated fatty acids andpolyunsaturated fatty acids. Oleic acid was dominant, followed by palmitic acid and linoleic acid. Among the n-3 PUFAs,DHA was the most dominant followed by linolenic acid. The ratio of n-3/n-6 PUFA was 0.77. Among the minerals, K washigh followed by Ca, Na, Fe, Zn, Se and Mn. From the present study, it can be concluded that rainbow trout has a rich amountof quality protein with well-balanced essential amino acids, PUFAs and minerals.Not Availabl

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Not AvailableA sixty-day feeding trial was carried out to elucidate the effect of dietary pyridoxine (PN) on hemato-immunological parameters in Labeo rohita fingerlings exposed to an elevated temperature (ET) of 33 °C. Two hundred and seventy fingerlings (6.71 ± 0.32 g) were randomly distributed into six treatments in triplicates (15 fish/tank). Five iso-nitrogenous (356.3 ± 2.7 g/kg crude protein) purified diets were prepared with graded levels (0, 10, 50, 100 and 200 mg/kg diet) of PN. Six treatment groups were P10T26 (10 mg) PN + ambient temperature (26 °C), P0T33 (0 mg PN + ET), P10T33 (10 mg PN + ET), P50T33 (50 mg PN + ET), P100T33 (100 mg PN + ET) and P200T33 (200 mg PN + ET). The responses of L. rohita fingerlings to dietary PN were assessed in terms of growth and by analysing some hemato-immunological parameters. When PN supplementation increased from 10 to 200 mg/kg diet, a significant improvement in weight gain percentage was observed. Erythrocyte (RBC) count, leucocyte (WBC) count, haemoglobin content and respiratory burst activity were significantly (p < 0.05) higher in 100 mg PN/kg diet-fed group than their non-PN-fed counterpart. Also, serum albumin, globulin and lysozyme activity were found significantly (p < 0.05) higher in PN-fed groups. The overall results indicated that dietary PN supplementation at 100 mg/kg diet may reverse the negative effects caused by ET and may protect the haemato-immunological status of L. rohita fingerlings reared at higher water temperature.Not Availabl

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Not AvailablePresent study was undertaken to explore the possibilities of inducing maturity and spawning of T. putitora under captivity through manipulation of environmental cues i.e. photoperiod and temperature. In experiment I, adult T. putitora were subjected to three photoperiod (8L:16D, 12L:12D and 16L:12D) regimes for 100 days. In females, darker photoperiod (8L:16D) significantly decreased the plasma estradiol levels compared to 12L:12D and 16L:8D photoperiods. Plasma 17α, 20β-diOH-P was significantly (p  .05) effect of temperature was observed on plasma levels of 11-KT of both sexes. Experiment III was meant to explore the possibility of achieving captive spawning by simulating natural spawning ground using a gravel bed bio-filter. Natural spawning occurred after four months of rearing in the simulated facility. Subsequently, fishes further spawned seven times in a period of 4 months on an interval of 15–20 days. Overall, our results suggested that captive maturity and spawning of golden mahseer can be achieved by manipulating the environmental cues. The results solved the prevailing decadal issue of captive maturation of golden mahseer which otherwise has been a major bottleneck for its wide spread rehabilitation and conservation programmes.Indian Council of Agricultural Research (ICAR

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Not AvailableThis study embodied the effect of sub-lethal nitrite exposure on growth and metabolic responses of Labeo rohita juveniles fed elevated levels of vitamin E (VE). Fishes fed with normal and elevated levels of VE for 60 days were exposed to sub-lethal nitrite (2.0 mg L−1) for another 45 days under same feeding regime. There were six treatment groups, viz, VE0−N, VE0+N, VE100−N, VE100+N, VE150+N and VE300+N. Except the groups VE0−N and VE100−N, all other groups were exposed to nitrite. Weight gain percentage was significantly lowest in VE0+N and highest weight gain was observed in VE100−N group. Dietary supplementation of VE augmented weight gain of nitrite exposed L. rohita. Similarly, protein efficiency ratio was lowest and highest in VE0+N and VE100−N respectively. Nitrite exposed groups recorded higher LDH, AST and ALT activities compared to their unexposed counterparts (VE0−N & VE100−N). The highest activities of LDH, AST and ALT were observed in VE0+N. Dietary supplementation with additional levels of VE found to significantly reduce the activities of these enzymes. Nitrite exposure was found to significantly reduce serum total protein, albumin and globulin levels and groups which are fed with additional amounts of VE (150 and 300 mg kg−1 diet) recorded total protein, albumin and globulin values similar to that of the nitrite unexposed groups. It was noticed that nitrite exposure has adversely affected growth, metabolic activity and immunological status of L. rohita and dietary supplementation with additional amounts of VE found to overcome the adverse effect of nitrite exposure.Not Availabl