Ecology, Environment and Conservation Paper

STUDIES ON LIMNOLOGICAL CHARACTERISTICS AND ZOOPLANKTON DIVERSITY IN DURGADAHALLI AND MYDALA LAKES OF TUMAKURU, KARNATAKA STATE, INDIA.

Shivaraju and M. Venkateshwarlu

Abstract

The specific status of limnological characteristics and diversity of zooplankton in Durgadahalli and Mydala Lakes have been studied in the period 2017-19. Diversity of zooplankton in the selected two lakes identified 35 species of zooplankton. In Durgadahalli lake 20 species were recorded, of which 14 are rotifers, 4 are cladoceraus and 2 are copepods. Among the rotifers, family Brachionidae reported as highest number of species (11 species), of which Genus Brachionus contain 08 species. Similarly, in Mydala lake recorded 26 species of zooplankton among which 17 are rotifers, 7 are cladoceraus and 2 are copepods. In rotifers, family Brachionidae contains high number of species (10 species), in which Genus Brachionus (08 species) represents the highest number. Most commonly occurring species are Brachionus angularis, B. caudatus, Keratellatropica, Filinia longiseta, Ceriodaphnia cornuta, Ceriodaphniacornuta, Diaphanosomasarsi and Moina micrura. The highest zooplankton population was recorded in rotifera and lesser in copepod in both the lakes. The water remained moderately alkaline (pH 7.07 and pH 7.27) while Biochemical Oxygen Demand (3.0 mg/l each), Dissolved Oxygen (7.5 mg/l and 5.32 mg/l), TDS (167 mg/l and 272 mg/l), chloride (15 mg/l and 27.5 mg/l), hardness (40 mg/l and 81.5 mg/l) showed low mean values respectively.