Macrobenthic Invertebrate Population of Chhirapani, a Hill Stream in Kumaon Himalaya, India.

In the hill stream, benthic fauna are an important component of natural food for coldwater fishes. The benthic population reflects the productive potential of the stream. This paper describes the seasonal fluctuation in the population of macrozoobenthos of a coldwater stream, Chhirapani, with reference to certain abiotic components. Low velocity of water, abundance of hydrophytes; optimal water temperature and higher dissolved oxygen influenced the composition of benthic fauna. The macrozoobenthic density was maximum (208.0±32.3 ind. m²) in winter and minimum (96.0± 17.9 ind. m^-2) in monsoon. Beatis, Rithrogena, Heptagenia, Hydropsyche, Chloroperla and Psephenus were the common taxa. The most dominant group of insect was Ephemeroptera comprising 37.53% of total benthic population and reflected the oligotrophic state of the stream. [ABSTRACT FROM AUTHOR]