A Study of Benthic Macroinvertebrate Fauna in a Tributary of Himalayan River Bhilangana, Uttarakhand, India

Abstract

The present study is focused on structural and functional composition of benthic macroinvertebrate fauna in the river Nailchami, a tributary of Bhilangana River. The seasonal samples were collected during March 2018 to February 2019 at three different stations (S1, S2, and S3) by lifting of stones and sieving of soft substrate (0.5 mm mesh size) from marked area (1ft square). Standard procedures were adopted to identify and analysis for preserved samples. The physico-chemical parameters varied among the stations. The total mean density varied seasonally at each station and found significantly different. The highest density was found in winter season followed by summer and monsoon. Fifty-eight invertebrate families were recorded among all the stations. Simulidae was most abundant family at all stations during summer season (S1-17.5%, S2-6.8%, S3- 11.3%). However, in the monsoon season, chironomidae was abundant at S1 (22.8%) and S3 (10.6%), while limnephilidae (16.2%) at S2. In winter season, stations S1, S2 and S3 were dominated by chironomidae (48%), limnephilidae (12.4%) and simulidae (16.7%), respectively. PCA ordination techniques identified characteristic benthic macroinvertebrate taxa at different stations. Gathering collectors were most abundant functional feeding groups at all stations as well as seasons. Thus, river indicated heterotrophic status along the river length.