Biological index of Benthic insects in Pilan River, Santa Cruz, Davao del Sur

Abstract

This study aimed to identify the different benthic insects that are present in Pilan River Sta. Cruz, Davao del Sur. Benthic insects are said to be organisms that do not have backbones but are considered as indicator species of water quality on their habitat. In conducting the research, qualitative and quantitative approaches were employed in discriminating and describing the samples. There were total of 263 individuals under 11 taxa in the upstream and 439 individuals under eight (8) taxa in the downstream of Pilan River wherein the physical and chemical parameters were also taken for observation. Specimens were cleared and examined to identify their family and morphological features as well as the pollution tolerance index they indicate. The research results showed the water quality status of the upstream and downstream of the river is on its very good condition. The research also found the diversity and abundance of insects on the habitat and also the factors that affect the species assemblage’s variations on the river.