Nilu Paul, A. K. Tamuli, R. Teron, J. Arjun
Abstract: Stream ecosystem biomonitoring has been widely used to assess the status of water. It provides information on the health of an ecosystem based on which organisms live in a waterbody. The benthic community is dependent on its surrounding and therefore, it serves as an indicator that reflects the overall condition of the ecosystem. Among the commonly used biomoniting approaches, biotic indices and multimetric approaches are most frequently used to evaluate the environment health of streams and rivers. The macro invertebrate fauna and physico-chemical parameters of Lungding stream of Dima Hasao district were studied seasonally from March 2017 to February 2018. A total of 13 species of benthic invertebrate fauna belonging to three phyla (Annelida, Arthropoda and Mollusca), five classes (Hirudinea, Gastropoda, Bivalvia, Crustacea, Insecta) and thirteen families (Hirudinidae, Physidae, Anomidae, Gammaridae, Panaediae, Baetidae Aeshnidae, Belostometidae, Hydrophilidae, Chaoboridae, Chironomidae) were found in the Lungding stream during the study. Gastropoda was predominant (23.71 %) followed by Crustacea, Bivalvia and Hirudinidae with percentage composition of 19 %, 16.59 % and 11.42 % respectively. Among Insects, Dipteran midges (Chaoboridae) with 8.84 % were the dominant group. Macroinvertebrates tolerance values ranged between 4 and10 and family biotic index values between 7.64 and 8.15.
Keywords: Lungding stream, Macroinvertebrate index, Macroinvertebrate tolerance value, Water quality