Benthic Macrofaunal Diversity and Abundance Across Habitat Gradients in the Riparian Zones of Luan River, Barangay Maguling, Maitum, Sarangani Province

Macrofaunal diversity and the physico-chemical features of the riparian zones of Luan River, Barangay Maguling, Maitum, were examined to detect underlying relationships between them. From 1162 individuals of macro-benthic invertebrates, twelve species (10 gastropods, two crustaceans) belonging to seven families (Ellobiidae, Neritidae, Pachychilidae, Potamididae, Thiaridae, Ocypodidae, and Varunidae) were identified. The macro-benthic invertebrate survey revealed that areas along Luan River had high diversity in both sites during the wet (H' = 2.307) and dry season (H' = 2.238) Dominance and Evenness values signified that the species were almost evenly distributed and equally present in all sites. Multivariate analysis using canonical correspondence analysis (CCA) done on wet season data sorted the gastropod species according to their habitat requirements and revealed a close correlation between pH and salinity. C. obtusa, P. scarabaeus and M. scabra were discovered to fairly tolerate increasing temperature while E. aurijudae was extremely sensitive even to low pH and salinity levels. During the dry season, pH and temperature changes were extremely inhibitory to H. oregonensis, E. aurisjudae and U. leptodactyla populations. To conclude, these interactions between species diversity and distribution on the one hand and environmental parameters on the other provide a more profound understanding of species diversity that cannot be gleaned by biodiversity indices alone.