24 research outputs found
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Not AvailableSpatial and temporal variation of rotifers in Lake Sattal of Western Himalaya was studied from January 2011 to December 2012. A total of 22 rotifer species could be identified in the lake with a biannual mean abundance of 2.07 × 106 individuals/m3 in eastern basin and 1.92 × 106 individuals/m3 in western basin having maximum abundance during summer season. The main factors regulating distribution patterns of rotifers are nutrients, viz. NH4-N, PO4-P, NO2-N, and NO3-N, and turbidity, pH, and transparency. Six species of rotifers were deliberated as important species based on importance value index. Keratella quadrata, Colurella obtusa, and Asplanchna priodonta flourish under low turbid conditions. Philodina roseola demonstrated as a phosphorous-tolerant species, whereas K. quadrata and C. obtusa are thermophilous and their distributions are highly influenced by pH and transparency. The total organic matter (TOM) of the sediment has a significant positive correlation with species richness and diversity. The hierarchical environmental descriptor suggests water chemistry has a greater significant role in assemblages of rotifers as compared to sediment characteristics.Not Availabl
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Not AvailableMultivariate statistical techniques are gaining popularity in the analysis of water quality data due to its simplicity when handling a large number of variables simultaneously and capable of producing more easily interpretable results for the evaluation of observed quality data. In this study, factor analysis and cluster analysis are applied to water quality data set obtained from Narmada River and an attempt has been made to present a strategy that reduces the measured parameters, locations and frequency without compromising the quality of the original data. Factor analysis shows that river water quality data consists of three significant components viz., animal waste discharges, sewage discharges and industrial discharges whereas Chloride, Bicarbonate Alkalinity and pH are the respective indicator variables. Cluster analysis also suggests that number of sampling sites as well as the sampling frequency can be consolidated. This reduced set of parameters, sampling sites and sampling frequency could be monitored over larger areas within the watershed to provide more detailed spatial information about sources and processes.Indian Council of Agricultural Research (ICAR
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Not AvailableIn this investigation, Golden Mahseer (Tor putitora) having an average body weight ranging between 3.5 and 650 gms were collected from Experimental Mahseer Hatchery and lake, Bhimtal in order to assess the food availability in their natural habitat as well as for the prediction of growth rate. Commonly used molecular indices for fish growth and feeding conditions include RNA concentration (µg/mg tissue) and its ratio to DNA (RNA/DNA). Most of the isolated DNA had no sign of degradation and the spectrophotometer analysis of absorbance at 260 and 280nm provided ratios ranging between 1.70 and 1.90 indicating that quality of DNA was good. The DNA and RNA concentration ranged between 4.06 and 8.86 and 0.92-to 23.70 µg/ mg respectively. The RNA/ DNA ratios ranged from 0.10 to 4.83 with the mean average of 2.52. The means of the RNA/ DNA ratio of the wild fish were relatively higher than that of the reared fry indicating that they were generally in better condition. A positive correlation was also observed between body mass/size of the fish with RNA/ DNA ratio. The RNA concentration and ratio of tissue RNA/ DNA have proven to be a reliable estimator of recent fish growth rate and food availability in their natural habitat.Not Availabl
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Not AvailableSome growth models used in fisheries are inappropriate for use with species whose growth is seasonal due to the assumption that growth is invariant over time. A modified version of the logistic model that incorporates cyclical (or seasonal) fluctuations in growth gave significantly improved results when it was fitted to observations of length-at-age from Tor putitora. The modified logistic model was obtained by introducing a sine wave function into the original model.Indian Council of Agricultural Research (ICAR
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Not AvailableIn the present investigation, an attempt was made to develop length-weight relationship of snow trout considering its 6 different species (Schizothorax plagiostomus, S. curvifrons, S. nige, S. esocinus, S. labiatus and Diptychus maculates) from Jhelum River, Kashmir, India. Analysis of covariance (ANCOVA) results showed that the existing 2 distinct groups of snow trout species regarding its length-weight relationship do not follow isometric growth. Furthermore, the data sets of 2 different groups are meaningfully fitted to allometric models with expected-value parameters.Indian Council of Agricultural Research (ICAR
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Not AvailableThe genetic polymorphism and gene flow rate among the Indian snow trout fish population S. richadsonii from three different locations viz., Chirapani stream of Champawat district, Kosi and Gola river of Nainital district, Uttarakhand State, India were assessed by employing twenty numbers of Randomly Amplified Polymorphic DNA (RAPD) markers. The overall percent polymorphisms among these three populations were 14.76 with 6.56, 4.92 and 3.28 in Chirapani, Kosi and Gola river population, respectively. Chirapani population had higher proportion of polymorphic loci as compared to the Kosi and Gola. The higher value of genetic distance (0.1565) was obtained between Chirapani and Gola population and the lower value of genetic distance was observed between Chirapani and Kosi (0.1058) river population. The cluster analysis revealed that in the formation of two clusters, one consisted of Chirapani and Kosi and the other was Gola fish population. Gst estimates among these populations showed some extent of homogeneity with lower genetic differentiation rate between populations and further suggested that higher tolerance to mutation, as expected that RAPD bands, arose from both coding and non-coding DNA regions. The findings revealed that the rate of gene flow in three populations seemed very low i.e. highly conserved its genetic diversity in their natural water bodies and indicative of little migration among populations (geographically isolated and not the possibilities man made interventions/introduction of similar kind of fish species). It is further concluded that the Chirapani, Kosi and Gola river populations of S. richardsonii were being conserved naturally in their habitat and the species actual genetic potential were being maintained (adaptation to local climatic conditions, reproduction, production traits and disease resistance trait etc) in their natural habitat.Not Availabl
<i>Mystus ngasep</i>, a new catfish species (Teleostei: Bagridae) from the headwaters of Chindwin drainage in Manipur, India
Mystus ngasep, a new species of bagrid catfish from the headwaters of Chindwin drainage in Manipur, India, is described here. It is distinguished from its congeners in having a unique combination of the following characters: a colour pattern of the body consisting of a distinct dark tympanic spot and three brown stripes separated by pale narrow longitudinal lines, cranial fontanel reaching the base of the occipital process, a long-based adipose fin contacting the base of the last dorsal-fin ray anteriorly, 16-19 gill rakers on the first branchial arch, a slender cleithral process, pectoral spine with 9-11 serrations on the posterior edge, eye with a diameter of 16.5-19.8 % HL and prepectoral length 22.2-26.0 % SL. The new species has been compared with its congeners from Myanmar and also from northeastern India
Redescription of the Striped Catfish <i>Mystus tengara</i> (Hamilton, 1822) (Siluriformes: Bagridae), India
The Bagrid Catfish Mystus tengara was described from a pond located in India under the genus Pimelodus. The validity of the fish has been confused and has frequently been treated as a synonym of Mystus vittatus. In this study, the species is rediagnosed and redescribed on the basis of fresh material collected from the Ganga-Brahmaputra drainage. M. tengara is diagnosed from congeners in having a unique combination of the following characters: body with a distinct tympanic spot and four brown stripes which are separated by a pale narrow interspace; origin of adipose-fin not reaching the base of the last dorsal-fin ray, 31-42 gill rakers on first branchial arch, eye rounded with a diameter 19.0-23.8 % HL and dorsal spine length 12.3-17.2 % SL, maxillary barbel length 254.5-360.5 % HL. A key for the identification of Mystus species from Ganga-Bramaputra drainage is also provided
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Not AvailableThe levels of key metabolic enzymes viz. Glucose 6 phosphate dehydrogenase, Lactate
dehydrogenase, Pyruvate kinase, Acetylcholine esterase and ATPase were monitored at varying time intervals in coldwater fish Barilius bendelisis exposed to 5°C. The levels of these enzymes increased to 236.23, 28.22, 68.66, 83.59 and 143.55% respectively as compared to control group of fishes during 96hrs of rearing in cold. The enzymatic values of pyruvate kinase, lactate dehydrogenase and ATPase levels increased considerably (P<0.01) just after 24 hrs of treatment while glucose 6 phosphate dehydrogenase and esterase increased significantly (P<0.01) after 48 hrs of cold treatment. Isozyme profiling of above enzymes also supports the data visually.
Moreover, two more isoforms of Pyruvate kinase were also observed in cold adapted fish
specimens than in control group. Twelve protein bands were also visualized when the samples from test fishes were run on the SDS-PAGE, one band of 29kD at Rf of 0.63 exhibited relatively. high intensity in the fish reared at cold temperature as compared to control group. Similarly, elevated levels of Hsp-70 were also detected (p<0.05) due to the cold stress given to the fishes for a period of 24- 96 hrs that also served as an early indicator of temperature stress in fish and played an important role in cold adaptation.Not Availabl
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Not AvailableSix months (January 2004- June 2004) sampling was done 50 km around Lucknow fish markets and fish farms. Fish and water samples were enriched in Alkaline Peptone Water and spread on Starch Ampicillin Agar. The presumptive identification was done by amylase test. Twenty-seven samples were processed and total 36 isolates of Aeromonas hydrophila were recovered. All isolates were resistant to Cephalothin, Ampicillin, Novobiocin, Nitrofurazone and sensitive to Ciprofloxacin, Chloramphenicol and Co-trimaxazole. Sixty percent isolates of A. hydrophila were aerolysin positive.Not Availabl