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Articles by R.K. Negi
Total Records ( 5 ) for R.K. Negi
  R.K. Negi and Bheem Dutt Joshi
  Genetic based study provide emphasis on the population study of geographically isolated population, gene flow among them and evolutionary history of the species. In the present study, we aimed to detect the genetic variations in species of genus Schistura from Uttarakhand. Very little is known for the pattern of distribution and genetic diversity of the species of genus Schistura from the Garhwal and Kumaun region. Out of six primer only four primers were used to generate the fragments patterns from the samples collected. Polymorphism within and between the populations were assayed and total 60 bands were amplified ranging from 1-150 kb. Maximum number of bands was observed in Schistura montanus from the Srinagar, Garhwal and Uttarkashi regions. Total 60 bands were amplified in the all four primer with high percentage of polymorphic loci 50% Schistura montanus from Garhwal region and 28.8% in the S. montanus from the Kumaun region were observed. The level of heterozygosity were found 0.006-0.18 in the all three species. The percentage of polymorphism was 50% within the populations and high heterozygosity the sample of S. montanus when compared with other species. Observed pattern of RAPD markers reveals that the samples from the Garhwal region exhibit high diversity and used four primers are sufficient to distinguish the different population in the both region except the samples of the S. gangiticus of Garhwal region.
  R.K. Negi and Vishal Rajput
  The study was undertaken to assess the phytoplankton diversity in relation to abiotic factors of Nainital lake of Kumaon Himalayas of Uttarakhand State, India. The samples were collected from the three selected study sites for the period from May, 2007 to April, 2009. A total of 25 genera of phytoplankton were reported belonging to 3 groups viz., bacillariophyceae (13 species), chlorophyceae (8 genera) and cyanophyceae with 4 genera. Members of bacillariophyceae and chlorophyceae were found to dominant during winter and monsoon months at all the sites. Site II has the maximum number of phytoplankton followed by Site III and Site I. Bacillariophyceae were positively correlated with GPP, chlorophyceae and with zooplankton while negatively correlated with alkalinity and dissolved solids and with chlorides at all the sites. Chlorophyceae was found to be positively correlated with hardness, GPP, bacillariophyceae and zooplankton while chlorophyceae was negatively correlated with alkalinity, total dissolved solids and chlorides. Cyanophyceae was positively correlated with GPP, NPP while negatively correlated with free CO2 and total dissolved solids. Maximum species richness was recorded as 0.458 for cyanophyceae at Site-I followed by bacillariophyceae (0.366) and minimum was observed in chlorophyceae (0.182) at Site-III. As far as species diversity is concerned, maximum diversity was observed in bacillariophyceae (2.329) and minimum in cyanophyceae (1.335). Abundance percentage was recorded maximum (56.91%) in chlorophyceae at Site-III and minimum as 2.52% in case of cyanophyceae.
  R.K. Negi and Sheetal Mamgain
  Over the last century, riverine ecosystems have suffered from intense human intervention resulting in habitat loss and degradation and as a consequence, many fish species have become highly endangered, particular in rivers where heavy demand is placed on freshwaters. In present study three study sites were selected along the stretch of river Tons. The study was carried out during December, 2007 to November, 2009. Water samples were collected each month and brought to the laboratory and analyzed with the standard methods. Fish sampling was carried out at all the three sites on monthly basis at day as well as at night time during the course of study. Statistical correlation between fish species richness and selected hydrological attributes showed that air temperature, water temperature, pH, Dissolved oxygen and free CO2 highly influenced the fish species distribution. Total 19 species of fishes belonging to five sub-families and two orders (Cypriniformes and Perciformes) and six genera were collected from the selected study sites. The Shannon-Weiner diversity index of three different sampling indicated a strong relationship with overall species richness, showed variation and ranged from 0.036-0.173. The highest fish diversity was recorded at site-III followed by sites-II and I. The low fish diversity at site. I may be due to high altitude (1563 m) as compared to the sites II (284 m) and site-III (217 m). Hence, it may be inferred that there is inverse relationship between fish diversity and altitude of the river.
  R.K. Negi and Aarti Maurya
  Aquatic ecosystem pollution by heavy metals is a worldwide concern. Heavy metals have the ability to bioaccumulate in aquatic organisms, particularly fish, which is a source of livelihood for humans. Between March 2012 and February 2014, we assessed heavy metal (Cu, Cr, Pb, Ni, Zn and Cd) contamination in two food fish species (Labeo rohita and Hypophthalmichthys molitrix) selected from Bhagwanpur fish pond in Roorkee, Haridwar, India. After acid digestion, the dried samples of fish tissues were analyzed for heavy metal concentrations by using atomic absorption spectrophotometery. Data obtained was analyzed using two way analysis of variance and Pearson’s correlation coefficient. The mean absorption of metals in different organs of L. rohita and H. molitrix ranged from 5.754±2.591-56.851±12.569 μg g–1 dry weight and from 5.455±3.651-53.625±11.432 μg g–1 dry weight, respectively. Heavy metal absorption was the highest in gill and liver tissues and the lowest in muscle tissues. Among all metals, Zn had the highest concentration in all the fish tissues. Statistical analysis revealed a significant variation (p<0.05) in heavy metal concentrations in the fish tissues during different seasons. The highest concentrations of heavy metals were found in the summer and the lowest in the spring. The concentrations of most of the studied heavy metals in the fish muscle (the edible part), liver, gill and scale tissues were higher than the permissible limits proposed by the World Health Organization, Food and Agriculture Organization and Ministry of Agriculture, Fisheries and Food.
  R.K. Negi and Sheetal Mamgain
  Present investigation was carried out to assess the seasonal variation of benthic macro-invertebrates from the Tons river, a tributary of Yamuna River in Garhwal Himalaya, Uttrakhand during December, 2007 to November, 2009. The seasonal benthic diversity was correlated with various physic-chemical parameters which documented that the macrobenthic diversity is mostly regulated by the dissolved oxygen in the water while temperature and free CO2 were found to be inversely correlated with the benthic fauna. Maximum diversity of benthos was reported at the upstream site (‘H’ 0.204) during the winter season while it was recorded minimum during the rainy season at all the sites. Maximum diversity is reported during the winter season at all the sites. The benthic fauna is represented by three phylum, 4 classes and 10 orders with Insecta emerging as the most dominant class. Maximum genera were reported from midstream site as it acts as ecotone between upstream and downstream.
 
 
 
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