Phytophilous macroinvertebrate assemblages in Nigeen lake of Kashmir Himalaya

Abstract

Macroinvertebrate assemblages associated with six aquatic macrophyte species were investigated in Nigeen Lake of Kashmir valley, Jammu and Kashmir. Across the lake surface, four locations were selected for collection of the aquatic macrophytes. The macrophytes were collected in plastic bags, labelled, and brought to laboratory for further analysis. The samples were sieved using a 0.5 mm mesh, sorted, and identified. During the study period, 18 macroinvertebrate species were recorded from 6 macrophytes. The macroinvertebrates belonged to eight families, seven orders, and extend over three phyla, viz.: Mollusca, Arthropoda, and Annelida. Phylum Arthropoda comprised of highest number (11) of species, followed by Mollusca (4), and Annelida (3). Maximum number of individuals was found attached to Myriophyllum verticillatum (75 ind./m²), Potamogeton crispus (71 ind./m²), Trapa natans (60 ind./m²), Potamogeton natans (57 ind./m²), Ceratophyllum demersum (38 ind./m²), and least for Potamogeton lucens (19 ind./m²). Principal component analysis (PCA) of the data resulted in two principal components (PCs) with eigenvalues > 1, explaining 86% of variance. Investigation of the factor loadings of macroinvertebrate assemblages linked with aquatic macrophytes on the first two PCs of the dataset revealed that relationship exhibit habitat gradients potentially affecting associated macroinvertebrates. The study demonstrated that macroinvertebrates differed with different vegetation types in terms of both density and diversity, and that plant structure plays a significant role in determining this variation. Macroinvertebrate communities benefit from increased macrophyte productivity. The study concludes that the certain taxa of macroinvertebrates are more comfortable to the high pollution loads and nutrient enrichment in the Nigeen lake.