Distribution of benthic macroinvertebrates in Central Indian rivers

Benthic macroinvertebrates are important component of aquatic ecosystem and are extensively used in bio-monitoring. The rivers of Central India are mainly impacted with agriculture; the river water is very under stress due to agriculture, domestic use. The three rivers of this region; Ken, Paisuni and Tons were studied longitudinally to test the ¿Biome Dependency Hypotheses¿. Insects were dominant in the Ken and Paisuni while Gastropods in the Tons. The taxonomic composition showed better relationship in Ken and Paisuni, while patchy distribution in Tons. Only few taxa show clear-cut trend of longitudinal increase or decrease. The characteristic taxa varied at each station within the river and also among the rivers. Substratum was most important factor for variation in taxonomic composition at various station in the Ken and Tons, while current velocity in the Paisuni. The environmental variables differed at larger scale (river), landuse in the Ken, current velocity in the Paisuni and substratum in the Tons. In the Ken two type of food chains were evident in upper and lower part i.e.grazing and detritus type. However, only detritus food chain was dominant in Paisuni and Tons.