The macro-gastropod communities of aquaculture-intensive lakes in the Philippines.

Intensive aquaculture in natural lakes has been shown to have negative effects on biodiversity. We conducted a study on the diversity and distribution of macro-gastropods (>1 cm) in three major lakes used for aquaculture on Luzon, the largest island in the Philippines archipelago, to provide baseline information on freshwater gastropods. Collections were made in 27 sampling sites in all three lakes. The samples were identified by examining the shell and radula. The gastropod collection comprised 13 species in six families, including 12 new records in Laguna de Bay and seven new records for Lake Taal. All species found in Lake Sampaloc are considered new records due to the lack of published literature on its gastropod fauna. There is low gastropod diversity in all three lakes. Distribution within the lakes is related to the presence of suitable habitats for each species rather than the size and geological origin of the lakes. The proximity of all three lakes may have facilitated gastropod dispersal between them, as all have similar environmental conditions brought about by intensive aquaculture activities. [ABSTRACT FROM AUTHOR]