Distribution and Seasonal Abundance of Benthic Macroinvertebrates in Lake Naini Tal,U.P., India

A total of thirty taxa of benthic macroinvertebrates were collected from Lake Naini Tal (area = 48 ha, mean depth = 16.2 m) situated 1937 m above sea-level in the Kumaun Region of the Himalaya. Of these, Chironomus plumosus and Tubifex tubifex were numerically dominant, while Viviparus bengalensis (Mollusca) was the most abundant species in terms of biomass. The seasonality was characterised by two peaks (May and December) both in density and biomass. The population density as well as biomass declined with progressive water depth up to 7 m. Beyond 7 m water depth not even a single individual was found.