AQUATIC INSECT COMMUNITIES IN RELATION WITH WATER QUALITY OF SELECTED TRIBUTARIES OF TASIK KENYIR TERENGGANU

Abstract

Composition and distribution of aquatic insect communities in relation with the water quality were studied in two selected tributaries of Taman Negara Terengganu Tasik Kenyir. A total number of 290 individuals of aquatic insects representing 21 families from six orders were collected using disturbance-removal sampling technique. Total abundance of aquatic insects was signifcantly higher in Sungai Perpek (198 individuals) compared with Sungai Cacing (92 individuals). In terms of taxon richness, a slightly more diverse and richer fauna was recorded in Sungai Perpek (16 families), but was lower in Sungai Cacing (11 families). Philopotamidae (Order: Trichoptera) was the most dominant family recorded in Sungai Perpek, whereas the most abundant family collected in Sungai Cacing was Perlidae (Order: Plecoptera). A relatively high abundant of Heptageniidae (Order: Ephemeroptera) was also found in both streams. Family Biotic Index (FBI), Biological Monitoring Work Party (BMWP) and Average Score Per Taxon (ASPT) showed that both streams were moderately good water quality. The fndings reveal that the diversity and abundances of aquatic insect communities in this study were closely related to the physico-chemical parameters and hydrological characteristics of the streams.