Limiting amino acids supplementation in low crude protein diets and their impacts on growth performance and carcass composition in Labeo rohita (rohu) adult fish / Limitação da suplementação de aminoácidos em dietas com baixo teor de proteína bruta e seus impactos no desempenho de crescimento e composição da carcaça em peixes adultos Labeo rohita (rohu)

Abstract Ninety days study was conducted in hapas installed in earthen ponds. Fish of an average initial weight (220g) were evenly distributed in triplicate groups within fifteen hapas. Five experimental diets labeled as T1 (25% CP and NRC recommended amino acid level) as control diet, T2 (with 2% low protein and 5% amino acid supplementation), T3 (with 2% low protein and 10% amino acid supplementation), T4 (with 4% low protein and 10% amino acid supplementation) and T5 (with 4% low protein and 20% amino acid supplementation) were prepared. Fish were fed with @3% of their body weight twice a day at 10.00 & 16:00 hour. Significantly higher percent weight gain (420.18 ± 66.84a) and specific growth rate (13499.33±1273.54a) along with improved feed conversion ratio (1.29 ± 0.09b) and hundred percent survivals were recorded during the trial. Furthermore proximate analysis of meat showed significant improvement in the crude protein level (81.77 ± 0.19a) served with diet containing 20% limiting amino acids mixture. Therefore, limiting amino acids can be a source of cost effective feed and use safely in L. rohita diet.

Resumo O estudo de 90 dias foi realizado em hapas instalados em tanques de terra. Peixes com peso inicial médio (220 g) foram distribuídos uniformemente em grupos triplicados em 15 hapas. Cinco dietas experimentais rotuladas como T1 (25% de CP e NRC recomendado nível de aminoácidos) como dieta controle, T2 (com 2% de proteína baixa e 5% de suplementação de aminoácidos), T3 (com 2% de proteína baixa e 10% de suplementação de aminoácidos), T4 (com 4% de baixa proteína e 10% de suplementação de aminoácidos) e T5 (com 4% de baixa proteína e 20% de suplementação de aminoácidos) foram preparadas. Os peixes foram alimentados com 3% do seu peso corporal duas vezes por dia às 10h00 e 16h00. Ganho de peso significativamente maior (420,18 ± 66,84a) e taxa de crescimento específico (13499,33 ± 1273,54a) juntamente com taxa de conversão alimentar melhorada (1, 29 ± 0,09b) e sobrevivência de cem por cento foram registrados durante o ensaio. Além disso, a análise aproximada da carne mostrou melhora significativa no nível de proteína bruta (81,77 ± 0,19a) servida com dieta contendo 20% de mistura de aminoácidos limitantes. Portanto, a limitação de aminoácidos pode ser uma fonte de alimentação econômica e usada com segurança na dieta de L. rohita.

Impact of dietary leaf extracts of Black pepper Piper nigrum L. on the growth, hematological and immunological parameters of Labeo rohita (Hamilton, 1822) cultured in glass aquaria / Impacto de extratos de folhas da dieta de pimenta-do-reino Piper nigrum L. sobre o crescimento, parâmetros hematológicos e imunológicos de Labeo rohita (Hamilton, 1822) cultivado em aquários de vidro

Abstract A study was conducted to evaluate the effect of Piper nigrum (black pepper) leaf extract on on the growth performance, proximate composition, hematological parameters, and immune response of Labeo rohita fingerlings with an average weight of 22.14 ± 0.98g. Aftrer acclimation for two weeks, fish (n=25) were randomly selected and placed in four glass aquaria (T0, T1, T2 and T3) at constant water temperature (30.0 ± 1.0 °C), pH (7.50 ± 0.5) and total hardness (200 ± 2.0 mgL,-1) for a period of 12 weeks, with three replicates each. Fish were fed with P. nigrum leaf extract supplemented feed @ 0.0%, 1.0%, 2.0% and 3.0% in T0, T1,T2 and T3, respectively. At the end of experiment, five fish were randomly selected from each aquaria for proximate composition, gut and skin microbial load, hematological parameters. Total proteins, albumins, and globulins were also recorded to evaluate immunological memory. The result revealed that fish in T2 showed better growth performance with an average weight gain of 56.11 ± 0.51 g. Thus, it had been concluded that Piper nigrum, a medicinal plant, can also be used to enhance the growth performance and immune response of Labeo rohita as attractive alternatives against antibiotics and vaccines and has shown no negative side effects on fish health as well as on its environment.

Resumo Um estudo foi conduzido para avaliar o efeito do extrato da folha de Piper nigrum (pimenta-do-reino) sobre o desempenho de crescimento, composição centesimal, parâmetros hematológicos e resposta imune de alevinos de Labeo rohita com peso médio de 22,14 ± 0,98g. Após aclimatação por duas semanas, os peixes (n = 25) foram selecionados aleatoriamente e colocados em quatro aquários de vidro (T0, T1, T2 e T3) em temperatura constante da água (30,0 ± 1,0 °C), pH (7,50 ± 0,5) e dureza total (200 ± 2,0 mgL-1) por um período de 12 semanas, com três repetições cada. Os peixes foram alimentados com ração suplementada com extrato de folha de P. nigrum @ 0,0%, 1,0%, 2,0% e 3,0% em T0, T1, T2 e T3, respectivamente. Ao final do experimento, cinco peixes foram selecionados aleatoriamente de cada aquário para composição centesimal, carga microbiana intestinal e cutânea e parâmetros hematológicos. Proteínas totais, albuminas e globulinas também foram registradas para avaliar a memória imunológica. O resultado revelou que os peixes em T2 apresentaram melhor desempenho de crescimento com ganho de peso médio de 56,11 ± 0,51 g. Assim, concluiu-se que Piper nigrum, uma planta medicinal, também pode ser usado para melhorar o desempenho de crescimento e resposta imunológica de Labeo rohita como alternativas atraentes contra antibióticos e vacinas e não mostrou efeitos colaterais negativos na saúde dos peixes, bem como sobre seu ambiente.

Impact of dietary leaf extracts of Black pepper Piper nigrum L on the growth, hematological and immunological parameters of Labeo rohita (Hamilton, 1822) cultured in glass aquaria / Impacto de extratos de folhas da dieta de pimenta-do-reino Piper nigrum L sobre o crescimento, parâmetros hematológicos e imunológicos de Labeo rohita (Hamilton, 1822) cultivado em aquários de vidro

A study was conducted to evaluate the effect of Piper nigrum (black pepper) leaf extract on on the growth performance, proximate composition, hematological parameters, and immune response of Labeo rohita fingerlings with an average weight of 22.14 ± 0.98g. After acclimation for two weeks, fish (n=25) were randomly selected and placed in four glass aquaria (T0, T1, T2 and T3) at constant water temperature (30.0 ± 1.0 °C), pH (7.50 ± 0.5) and total hardness (200 ± 2.0 mgL,-¹) for a period of 12 weeks, with three replicates each. Fish were fed with P. nigrum leaf extract supplemented feed @ 0.0%, 1.0%, 2.0% and 3.0% in T0, T1, T2 and T3, respectively. At the end of experiment, five fish were randomly selected from each aquaria for proximate composition, gut and skin microbial load, hematological parameters. Total proteins, albumins, and globulins were also recorded to evaluate immunological memory. The result revealed that fish in T2 showed better growth performance with an average weight gain of 56.11 ± 0.51 g. Thus, it had been concluded that Piper nigrum, a medicinal plant, can also be used to enhance the growth performance and immune response of Labeo rohita as attractive alternatives against antibiotics and vaccines and has shown no negative side effects on fish health as well as on its environment.

Um estudo foi conduzido para avaliar o efeito do extrato da folha de Piper nigrum (pimenta-do-reino) sobre o desempenho de crescimento, composição centesimal, parâmetros hematológicos e resposta imune de alevinos de Labeo rohita com peso médio de 22,14 ± 0,98g. Após aclimatação por duas semanas, os peixes (n = 25) foram selecionados aleatoriamente e colocados em quatro aquários de vidro (T0, T1, T2 e T3) em temperatura constante da água (30,0 ± 1,0 °C), pH (7,50 ± 0,5) e dureza total (200 ± 2,0 mgL-¹) por um período de 12 semanas, com três repetições cada. Os peixes foram alimentados com ração suplementada com extrato de folha de P. nigrum @ 0,0%, 1,0%, 2,0% e 3,0% em T0, T1, T2 e T3, respectivamente. Ao final do experimento, cinco peixes foram selecionados aleatoriamente de cada aquário para composição centesimal, carga microbiana intestinal e cutânea e parâmetros hematológicos. Proteínas totais, albuminas e globulinas também foram registradas para avaliar a memória imunológica. O resultado revelou que os peixes em T2 apresentaram melhor desempenho de crescimento com ganho de peso médio de 56,11 ± 0,51 g. Assim, concluiu-se que Piper nigrum, uma planta medicinal, também pode ser usado para melhorar o desempenho de crescimento e resposta imunológica de Labeo rohita como alternativas atraentes contra antibióticos e vacinas e não mostrou efeitos colaterais negativos na saúde dos peixes, bem como sobre seu ambiente.

Limiting amino acids supplementation in low crude protein diets and their impacts on growth performance and carcass composition in Labeo rohita (rohu) adult fish / Limitação da suplementação de aminoácidos em dietas com baixo teor de proteína bruta e seus impactos no desempenho de crescimento e composição da carcaça em peixes adultos Labeo rohita (rohu)

Ninety days study was conducted in hapas installed in earthen ponds. Fish of an average initial weight (220g) were evenly distributed in triplicate groups within fifteen hapas. Five experimental diets labeled as T1 (25% CP and NRC recommended amino acid level) as control diet, T2 (with 2% low protein and 5% amino acid supplementation), T3 (with 2% low protein and 10% amino acid supplementation), T4 (with 4% low protein and 10% amino acid supplementation) and T5 (with 4% low protein and 20% amino acid supplementation) were prepared. Fish were fed with @3% of their body weight twice a day at 10.00 & 16:00 hour. Significantly higher percent weight gain (420.18 ± 66.84a) and specific growth rate (13499.33±1273.54a) along with improved feed conversion ratio (1.29 ± 0.09b) and hundred percent survivals were recorded during the trial. Furthermore proximate analysis of meat showed significant improvement in the crude protein level (81.77 ± 0.19a) served with diet containing 20% limiting amino acids mixture. Therefore, limiting amino acids can be a source of cost effective feed and use safely in L. rohita diet.

O estudo de 90 dias foi realizado em hapas instalados em tanques de terra. Peixes com peso inicial médio (220 g) foram distribuídos uniformemente em grupos triplicados em 15 hapas. Cinco dietas experimentais rotuladas como T1 (25% de CP e NRC recomendado nível de aminoácidos) como dieta controle, T2 (com 2% de proteína baixa e 5% de suplementação de aminoácidos), T3 (com 2% de proteína baixa e 10% de suplementação de aminoácidos), T4 (com 4% de baixa proteína e 10% de suplementação de aminoácidos) e T5 (com 4% de baixa proteína e 20% de suplementação de aminoácidos) foram preparadas. Os peixes foram alimentados com 3% do seu peso corporal duas vezes por dia às 10h00 e 16h00. Ganho de peso significativamente maior (420,18 ± 66,84a) e taxa de crescimento específico (13499,33 ± 1273,54a) juntamente com taxa de conversão alimentar melhorada (1, 29 ± 0,09b) e sobrevivência de cem por cento foram registrados durante o ensaio. Além disso, a análise aproximada da carne mostrou melhora significativa no nível de proteína bruta (81,77 ± 0,19a) servida com dieta contendo 20% de mistura de aminoácidos limitantes. Portanto, a limitação de aminoácidos pode ser uma fonte de alimentação econômica e usada com segurança na dieta de L. rohita.

Impact of dietary leaf extracts of Black pepper Piper nigrum L. on the growth, hematological and immunological parameters of Labeo rohita (Hamilton, 1822) cultured in glass aquaria

Abstract A study was conducted to evaluate the effect of Piper nigrum (black pepper) leaf extract on on the growth performance, proximate composition, hematological parameters, and immune response of Labeo rohita fingerlings with an average weight of 22.14 ± 0.98g. Aftrer acclimation for two weeks, fish (n=25) were randomly selected and placed in four glass aquaria (T0, T1, T2 and T3) at constant water temperature (30.0 ± 1.0 °C), pH (7.50 ± 0.5) and total hardness (200 ± 2.0 mgL,-1) for a period of 12 weeks, with three replicates each. Fish were fed with P. nigrum leaf extract supplemented feed @ 0.0%, 1.0%, 2.0% and 3.0% in T0, T1,T2 and T3, respectively. At the end of experiment, five fish were randomly selected from each aquaria for proximate composition, gut and skin microbial load, hematological parameters. Total proteins, albumins, and globulins were also recorded to evaluate immunological memory. The result revealed that fish in T2 showed better growth performance with an average weight gain of 56.11 ± 0.51 g. Thus, it had been concluded that Piper nigrum, a medicinal plant, can also be used to enhance the growth performance and immune response of Labeo rohita as attractive alternatives against antibiotics and vaccines and has shown no negative side effects on fish health as well as on its environment.

Resumo Um estudo foi conduzido para avaliar o efeito do extrato da folha de Piper nigrum (pimenta-do-reino) sobre o desempenho de crescimento, composição centesimal, parâmetros hematológicos e resposta imune de alevinos de Labeo rohita com peso médio de 22,14 ± 0,98g. Após aclimatação por duas semanas, os peixes (n = 25) foram selecionados aleatoriamente e colocados em quatro aquários de vidro (T0, T1, T2 e T3) em temperatura constante da água (30,0 ± 1,0 °C), pH (7,50 ± 0,5) e dureza total (200 ± 2,0 mgL-1) por um período de 12 semanas, com três repetições cada. Os peixes foram alimentados com ração suplementada com extrato de folha de P. nigrum @ 0,0%, 1,0%, 2,0% e 3,0% em T0, T1, T2 e T3, respectivamente. Ao final do experimento, cinco peixes foram selecionados aleatoriamente de cada aquário para composição centesimal, carga microbiana intestinal e cutânea e parâmetros hematológicos. Proteínas totais, albuminas e globulinas também foram registradas para avaliar a memória imunológica. O resultado revelou que os peixes em T2 apresentaram melhor desempenho de crescimento com ganho de peso médio de 56,11 ± 0,51 g. Assim, concluiu-se que Piper nigrum, uma planta medicinal, também pode ser usado para melhorar o desempenho de crescimento e resposta imunológica de Labeo rohita como alternativas atraentes contra antibióticos e vacinas e não mostrou efeitos colaterais negativos na saúde dos peixes, bem como sobre seu ambiente.

Limiting amino acids supplementation in low crude protein diets and their impacts on growth performance and carcass composition in Labeo rohita (rohu) adult fish

Abstract Ninety days study was conducted in hapas installed in earthen ponds. Fish of an average initial weight (220g) were evenly distributed in triplicate groups within fifteen hapas. Five experimental diets labeled as T1 (25% CP and NRC recommended amino acid level) as control diet, T2 (with 2% low protein and 5% amino acid supplementation), T3 (with 2% low protein and 10% amino acid supplementation), T4 (with 4% low protein and 10% amino acid supplementation) and T5 (with 4% low protein and 20% amino acid supplementation) were prepared. Fish were fed with @3% of their body weight twice a day at 10.00 & 16:00 hour. Significantly higher percent weight gain (420.18 ± 66.84a) and specific growth rate (13499.33±1273.54a) along with improved feed conversion ratio (1.29 ± 0.09b) and hundred percent survivals were recorded during the trial. Furthermore proximate analysis of meat showed significant improvement in the crude protein level (81.77 ± 0.19a) served with diet containing 20% limiting amino acids mixture. Therefore, limiting amino acids can be a source of cost effective feed and use safely in L. rohita diet.

Resumo O estudo de 90 dias foi realizado em hapas instalados em tanques de terra. Peixes com peso inicial médio (220 g) foram distribuídos uniformemente em grupos triplicados em 15 hapas. Cinco dietas experimentais rotuladas como T1 (25% de CP e NRC recomendado nível de aminoácidos) como dieta controle, T2 (com 2% de proteína baixa e 5% de suplementação de aminoácidos), T3 (com 2% de proteína baixa e 10% de suplementação de aminoácidos), T4 (com 4% de baixa proteína e 10% de suplementação de aminoácidos) e T5 (com 4% de baixa proteína e 20% de suplementação de aminoácidos) foram preparadas. Os peixes foram alimentados com 3% do seu peso corporal duas vezes por dia às 10h00 e 16h00. Ganho de peso significativamente maior (420,18 ± 66,84a) e taxa de crescimento específico (13499,33 ± 1273,54a) juntamente com taxa de conversão alimentar melhorada (1, 29 ± 0,09b) e sobrevivência de cem por cento foram registrados durante o ensaio. Além disso, a análise aproximada da carne mostrou melhora significativa no nível de proteína bruta (81,77 ± 0,19a) servida com dieta contendo 20% de mistura de aminoácidos limitantes. Portanto, a limitação de aminoácidos pode ser uma fonte de alimentação econômica e usada com segurança na dieta de L. rohita.

Monitoring pond water quality to improve the production of Labeo rohita (Hamilton, 1822) in Bannu Fish Hatchery of Bannu district, Khyber Pakhtunkhwa province; An Implications for artificial fish culture

Abstract The water quality parameters of a fish pond are essential to be managing properly under control for successful operations of fish culture. Improper management of pond water quality during the juvenile stages can create stressful conditions to produce various harmful diseases, which may decrease the fish quality and results in low profits. The present study was aimed to monitored important water quality parameters of nursery ponds of Labeo rohita culturing in Bannu fish hatchery. The study duration was 75 days extends from 10th June to 24th August 2019 for the successful culture of this specie which can play a significant role in breeding season. Furthermore, the concentration of some heavy metals like copper (Cu), nickel (Ni), manganese (Mn), iron (Fe), cadmium (Cd), and zinc (Zn) in pond water and fry stages of this species was also determined. The data obtained from all water quality parameters were analyzed expressed as range, mean and standard deviation using MS Excel 2013. The obtained results of 75 days study revealed that the water pH & temperature, electric conductivity, total dissolved solids (TDS), and total dissolved oxygen (DO) of pond water samples were found within a tolerable limit except salinity and dissolved ammonia concentration were not permissible for fish growth. The average concentration of heavy metals in pond water exhibited descending order Fe>Ni>Mn>Zn>Cd>Ni, which was found in acceptable ranges. Whereas, the average values of heavy metals in fry stages were in the order of Zn>Fe>Ni>Cu>Cd>Mn, and found within the recommended values of WHO/FAO. Thus, it was concluded from this study that good water quality is a precondition, maintaining balanced levels of water quality parameters is fundamental for both the health and growth of fish culture which is quite necessary for assuring increased fish productivity. It is recommended to monitor and assess water quality parameters on a routine basis for promoting healthy fish culture.

Resumo Os parâmetros de qualidade da água de um viveiro de peixes são essenciais para um manejo adequado e sob controle para operações bem-sucedidas de piscicultura. O manejo inadequado da qualidade da água do tanque durante os estágios juvenis pode criar condições estressantes para a produção de várias doenças nocivas, o que pode diminuir a qualidade do peixe e resultar em baixos lucros. O presente estudo teve como objetivo monitorar importantes parâmetros de qualidade da água de viveiros de cultivo de Labeo rohita em incubadora de peixes Bannu. A duração do estudo foi de 75 dias, estendendo-se de 10 de junho a 24 de agosto de 2019 para o sucesso do cultivo dessa espécie que pode desempenhar papel significativo na época de reprodução. Além disso, a concentração de alguns metais pesados como cobre (Cu), níquel (Ni), manganês (Mn), ferro (Fe), cádmio (Cd) e zinco (Zn) na água do tanque e estágios de fritura dessa espécie também foram determinados. Os dados obtidos de todos os parâmetros de qualidade da água foram analisados expressos como faixa, média e desvio padrão usando o MS Excel 2013. Os resultados obtidos de 75 dias de estudo revelaram que o pH e temperatura da água, condutividade elétrica, sólidos totais dissolvidos (TDS) e total de oxigênio dissolvido (OD) das amostras de água do lago foram encontrados dentro de um limite tolerável, exceto salinidade e concentração de amônia dissolvida não eram permitidas para o crescimento dos peixes. A concentração média de metais pesados na água da lagoa apresentou ordem decrescente Fe > Ni > Mn > Zn > Cd > Ni, que foi encontrada em faixas aceitáveis. Já os valores médios dos metais pesados nos estágios de fritura foram da ordem de Zn > Fe > Ni > Cu > Cd > Mn, e encontrados dentro dos valores recomendados pela OMS/FAO. Assim, concluiu-se deste estudo que a boa qualidade da água é uma condição prévia, manter níveis equilibrados dos parâmetros de qualidade da água é fundamental para a saúde e crescimento da piscicultura, o que é bastante necessário para garantir o aumento da produtividade piscícola. Recomendam-se monitorar e avaliar os parâmetros de qualidade da água em uma base rotineira para promover a piscicultura saudável.

Monkeypox and Monkey Fever: Basic Understanding for Better Community Participation in Disease Control

Fish is used as a great source of food and the quality of its meat can be indicated by fat and protein contents as well as low quantity of water in fish meat. Therefore, the present study was performed for improvement in weight, feed-conversion ratio, protein-efficiency ratio, and growth. The experiment was performed at commercial level in field (pond) and the influence of fish meal protein on growth of Labeo rohita was investigated in 60 days culture trials. 90 fingerlings (Size: 4.97 to 6.04; Weight: 4.15 to 4.20) were maintained in well aerated 280 L three glass tanks in triplicate. These glass tanks were named as T1, T2 and T3. T1 was consisted of 30% crude protein with control diet containing proteins, fats vitamins and fibres, T2 consisted of 35% protein with control diet, while T3 consisted of only control diet (rice polish). The fish were fed 4% percent of their body weight twice a day at twelve hours interval for 60 days. There was a significant increase (p<0.05) in body weight, feed-conversion ratio, protein-efficiency ratio, and gross fish production of fish having 35% fish meal protein with control diet (T2) when compared with 30% fish meal protein with control diet T1 and control diet T3. These findings suggest that 35% fishmeal protein appear to be sufficient for obtaining optimum growth in fish.

Studies of Cypermethrin Activity on Steroidogenesis in Male Labeo Rohita.

Cypermethrin is a widely used type II Pyrethroid. As such it has become a contaminant in fresh water aquatic ecosystems. To know its toxic effect on steroidogenesis in male fish Labeo rohita, we have exposed six male fish to 10 and 20 μg/L of Cypermethrin for six days. The plasma concentration of Vitellogenin (VTG), testosterone (T) and 11-ketotestosterone (11 KT) were evaluated. Vitellogenin levels increased with increasing concentration of Cypermethrin, where as Testosterone and 11-Ketotestosterone levels decreased with increasing concentration of Cypermethrin.

Effect of Dactylogyrus catlaius (Jain 1961) infection in Labeo rohita (Hamilton 1822): Innate immune responses and expression profile of some immune related genes.

The monogenean ectoparasite, Dactylogyrus sp. is a major pathogen in freshwater aquaculture. The immune responses in parasitized fish were analyzed by quantitation of innate immune factors (natural agglutinin level, haemolysin titre, antiprotease, lysozyme and myeloperoxidase activities) in serum and immune-relevant gene expression in gill and anterior kidney. The antiprotease activity and natural agglutinin level were found to be significantly higher and lysozyme activity was significantly lower in parasitized fish. Most of the genes viz., β2-microglobulin (β2M), major histocompatibility complex I (MHCI), MHCII, tumor necrosis factor α (TNFα) and toll-like receptor 22 (TLR22) in gill samples were significantly down-regulated in the experimental group. In the anterior kidney, the expression of superoxide dismutase and interleukin 1β (IL1β) were significantly up-regulated whereas a significant down regulation of MHCII and TNFα was also observed. The down-regulation of most of the genes viz, MHCI, β2M, MHCII, TLR22 and TNFα in infected gills indicated a well evolved mechanism in this parasite to escape the host immune response. The modulation of innate and adaptive immunity by this parasite can be further explored to understand host susceptibility.

Age and growth in the Indian major carp Labeo rohita Cypriniformes: Cyprinidae from tropical rivers of Ganga basin, India / Edad y crecimiento de la carpa mayor de la India Labeo rohita Cypriniformes: Cyprinidae de los ríos tropicales de la cuenca Ganga, India

Labeo rohita is a member of the Indian major carp species and originally an inhabitant of the Ganga river network in India. It is among the top ten aquaculture species of the world. Since there is a lack of information on the growth pattern of the wild populations of this species, this study aimed at evaluating the pattern of age and growth, to support the development of effective management plans. A total of 1 082 samples of L. rohita were obtained from May 2009 to July 2012 in six drainages of the Ganga basin. Scales of the fish were used to determine the age and growth by analyzing the annual rings growth. Out of six populations, a maximum 8 age classes were recorded from two rivers Betwa and Sharda. The back-calculated lengths at 8 age class ranged from 86.22cm to 91.66cm. However, for the rest of rivers up to 7 age classes were recorded. Among growth parameters, specific rate of length increase Cl and specific rate of weight increase Cw showed decreasing trend, and three distinct life stages of L. rohita were recorded based on growth constant data Clt. Analysis of variance ANOVA of the back-calculated length data set of six populations indicated a significant difference p0.05. All three populations showed significant variation in length attainment during 1 and 3 age groups, while two populations showed significant variation in length attainment during the 2 and 7 age classes. Additionally, analysis of age frequency at different length intervals indicated that with increase in age class, number of fish samples was reduced. Since the pattern of life history traits of L. rohita have not been attempted in the recent past; therefore, this study will guide fisheries biologists about the current stock structure of this fish across different spatial scale of the Ganga basin.

Labeo rohita es de las principales especies de carpas hindúes y originalmente un habitante de la red del río Ganges en la India. Se encuentra en la lista de las diez especies principales de la acuacultura mundial. Puesto que no hay información sobre el patrón de crecimiento de las poblaciones silvestres de esta especie, este estudio tuvo como objetivo evaluar el patrón de edad y crecimiento para apoyar el desarrollo de planes de gestión eficaces. Un total de 1 082 muestras de L. rohita se obtuvieron en el periodo de mayo 2009 a Julio 2012, en seis desembocaduras de la cuenca del río Ganges. Las mediciones de los peces fueron utilizadas para determinar la edad y el crecimiento mediante el análisis de los anillos de crecimiento anuales. De las seis poblaciones, se registró un máximo de categoría de edad 8 en dos ríos Betwa y Sharda. Las longitudes de retrocálculo en la edad 8 variaron entre 86.22-91.66cm. De los parámetros de crecimiento, la tasa específica de aumento de longitud Cl y la tasa específica de aumento de peso Cw mostraron una tendencia decreciente, y basado en los datos constantes de crecimiento Clt se registraron distintas fases del ciclo de vida de L. rohita. El análisis de variancia ANOVA de los datos de longitud de retrocálculo de seis poblaciones indicó una diferencia significativa p0.05. Las tres poblaciones mostraron una variación significativa en la obtención de la longitud durante los grupos de edad 1 y 3, mientras que dos poblaciones mostraron una variación significativa en lograr la longitud durante los tipos de edades 2 y 7. Además, el análisis de la frecuencia de la edad en diferentes intervalos de longitude indicó que, con el aumento de la categoría de la edad, se redujo el número de muestras de peces. Dado que el patrón de rasgos de la historia de la vida de L. rohita no se ha tratado en el pasado reciente, este estudio será una guía para los biológos de peces acerca de la actual estructura de la población de estos peces en diferentes escalas espaciales de la cuenca del Ganges.

Effect of exposure to sublethal concentrations of sodium cyanide on the carbohydrate metabolism of the Indian Major Carp Labeo rohita (Hamilton, 1822)

Experiments were designed to study in-vivo effects of sodium cyanide on biochemical endpoints in the freshwater fish Labeo rohita. Fish were exposed to two sublethal concentrations (0.106 and 0.064mg/L) for a period of 15 days. Levels of glycogen, pyruvate, lactate and the enzymatic activities of lactate dehydrogenase (LDH), succinate dehydrogenase (SDH), glucose-6-phosphate dehydrogenase (G6PDH), phosphorylase, alkaline phosphatase (ALP), acid phosphatase (AcP) were assessed in different tissues (liver, muscle and gills). Result indicated a steady decrease in glycogen, pyruvate, SDH, ALP and AcP activity with a concomitant increase in the lactate, phosphorylase, LDH and G6PD activity in all selected tissues. The alterations in all the above biochemical parameters were significantly (p<0.05) time and dose dependent. In all the above parameters, liver pointing out the intensity of cyanide intoxication compare to muscle and gills. Study revealed change in the metabolic energy by means of altered metabolic profile of the fish. Further, these observations indicated that even sublethal concentrations of sodium cyanide might not be fully devoid of deleterious influence on metabolism in L. rohita.

Studies on the histopathological changes in selected tissues of fish Labeo rohita exposed to phenol.

Histopathological changes in vital tissues like gills, liver and kidney in the fish Labeo rohita exposed for 8 days to sublethal (5.2 mgl-1) and lethal concentration (25.09 mgl-1) of phenol were studied. The observed histopathological changes in the gills were epithelial hyperplasia with lamellar fusion, epithelial hypertrophy, edema, general necrosis, increased mucous production and degeneration of primary and secondary gill lamellae at sublethal (5.2 mg l-1) and degenerated primary and secondary gill lamellae, lamellar fusion and lamellar disorganization at lethal (25.09 mg l-1) concentration. In the liver, the changes include as: formation of number of vacuoles, enlargement of nuclei of some cells, enlarged sinusoids with numerous blood cells and atrophic areas at sublethal (5.2 mg l-1) concentration and nuclear and cytoplasmic degeneration and melanomacrophages aggregates at lethal (25.09 mg l-1) concentration. In case of kidney, the changes were: degeneration of proximal and distal convoluted tubule, vacuolation of renal interstitial tissue and deformation of the nuclear membrane of some cells at sublethal (5.2 mg l-1) and occlusion of tubular lumen, cloudy swelling degeneration and hyaline droplets degeneration at lethal (25.09 mg l-1) concentration.

Behavioural and histopathological effects of azodye on kidney and gills of Labeo rohita fingerlings.

The present paper emphasizes on the histopathological effects of an azo dye, Direct Green 6 on the kidney and gills of Labeo rohita by light microscopy. Fingerlings were exposed to sublethal concentrations (2.5, 5.0 and 10.0 ppm) of dye for 5, 10 and 15 days to study histopathological changes. No histopathological changes were seen in the kidney and gills of control fingerlings. Unlike control fingerlings, both the target organs showed some histopathological changes. Fingerlings exposed to 2.5 ppm concentration of the dye showed shrinkage of glomerulus, increased peritubular space, decreased lumen while 5.0 ppm produced haemorrhage in the interstitial tissue and mild degeneration in the kidney. Necrosis in the tubular epithelium, distruction of cell membrane and loss of cellular cytoplasm were observed in kidney of fingerlings exposed to 10 ppm dye concentration. Gills of fingerlings exposed to 2.5 ppm of dye showed aneurism and mild degenerated central axis. 5 ppm of dye concentration produced remarkable changes like epithelial lifting, hyperplasia, enlarged and vacuolated cartilage cells. Haemorrhagic tip, fusion and curling of secondary gill lamellae and at some places complete removal of them were also observed in gills of fingerlings exposed to 10 ppm.

Stock assessment of fish species Labeo rohita, Tor tor and Labeo calbasu in the rivers of Vindhyan region, India.

A study was conducted on the economically important fishes Labeo rohita (Hamilton 1822), Tor tor (Hamilton 1822) and Labeo calbasu (Hamilton 1822) stocks from the Ken, the Paisuni and the Tons rivers in the Vindhyan region. Asymptotic length was maximum in L. rohita (946, 833 and 962 mm) as compared with T. tor (822, 787 and 946 mm) and minimum in L. calbasu (567, 612 and 692 mm) in the Ken, the Paisuni and the Tons rivers, respectively. The growth coefficient and total mortality was maximum in T. tor compared to L. rohita and minimum in L. calbasu. Fishing mortality was maximum in T. tor (2.9, 4.57 and 3.44) and minimum in L. calbasu (0.51, 1.21 and 1.18) while natural mortality was maximum in L. rohita (0.74, 0.94 and 1.86) and minimum in L. calbasu (0.47, 0.65 and 0.68). Natural mortality indicated that the habitat was more suitable for L. calbasu. Comparatively, fishing pressure was very high in T. tor than L. rohita and L. calbasu. Exploitation rate was maximum in T. tor (0.71, 0.82 and 0.84) compared to L. rohita (0.77, 0.74 and 0.56) and minimum in L. calbasu (0.52, 0.65 and 0.63) in the Ken, Paisuni and Tons rivers, respectively.

Studies on effects of chronic exposure of endosulfan to Labeo rohita.

The major carp, Labeo rohita (Hamilton) upon chronic exposure to endosulfan showed hyperglycemia (60.11 to 117.71 mg 100 ml-1) and hypercholestemia (51.78 to 76.87 mg 100 ml-1) of blood when compared to the control. As a result of the insecticidal stress, the tissue metabolites and enzymes like AST and ALT revealed significant alterations. The hormones T3 (0.53 to 1.35 /ml l-1) and TSH (0.48 to 0.32 /ml l-1) were also affected by the endosulfan even in sub lethal concentration. Signficant histopathological alterations were observed in liver and gill of treated fishes. The reason for the significant alterations in tissue sugars, aminoacids, cholesterol, protein, enzymes and homones and the histopathological changes is discussed.