Species composition and abundance of gastropods in the Bigaan River

Abstract

Bigaan river is around 19 kilometers (km) from Gango, Libona, Bukidnon down to Cagayan de Oro City (Philippines) and ends up in the Macajalar Bay. This study investigated species composition and abundance of gastropods along the river's stretch during wet and dry seasons. Sampling areas differ in elevation. Three species were found to be relatively abundant: N. porcata>M. tuberculata>P. canaliculata. Two sepcies -P. canaliculata and M. tuberculata were considered to be site-specific while N. porcata was present in all sampling areas.Abundance differs between seasons. Except for N. porcata, the 2 other species have small, medium and large sizes. With various kinds of pollutants discharged to Bigaan river, abundance of species faces huge threat. Therefore, measures in implementing programs for environmental protection need urgent and serious attention.