Mangrove-Associated Gastropod and Bivalve (Phylum: Mollusca) Diversity in Barangay Bula, General Santos City

Mangrove ecosystems support rich biodiversity that relies on the resources they provide, including the representatives of the Class Gastropoda and Class Bivalvia under the Phylum Mollusca. This present study aims to assess the species diversity of gastropod and bivalve populations in the Bula Mangrove Sanctuary, Barangay Bula, General Santos City. Studies regarding molluscan fauna in Sarangani are available, however, the mangrove-associated molluscan fauna in coastal areas of General Santos City is yet to be studied. The Bula Mangrove Sanctuary has an estimated length of 188 m, where six (6) species of mangroves are present. Transect-quadrat plots are established to account for the distribution and evenness of the gastropod and bivalve across the study site. The physicochemical parameters of the area (i.e., temperature, salinity, pH, and dissolved oxygen) are recorded and analyzed using the Canonical Correspondence Analysis (CCA) of the PAST software to assess their influence on the species diversity of the gastropods and bivalves present in the area. From the conducted of the study, 726 individual specimens from the Class Gastropoda and Class Bivalvia combined. Roughly 94% (684 specimens) of the population came from the Class Gastropoda whereas the 6% (42 specimens) is comprised of the Class Bivalvia. Specifically, the Class Gastropoda is represented by six (6) orders, 14 families, 18 genera, and 25 species. Class Bivalvia is composed of four (4) orders, five (5) families, seven (7) genera, and eight (8) in total. The family Nassariidae (Class Gastropoda) and the Family Arcidae (Class Bivalvia) rank the highest in the diversity indices. Moreover, the physicochemical parameters were within the threshold and do not incur detrimental impacts on the gastropod and bivalve species.