Community Structure of Polychaete Families in Mangroves of Guang-Guang Point and Nearby Shores of Pujada Bay, Mati, Davao Oriental

Abstract

The community structure and function of Polychaete families in mangroves of Guang-guang Point and nearby shores of Pujada Bay, Matis Davao Oriental were examined. A total of fifteen stations were sampled and sampling sites varied according to environmental characteristics which differed in type of sediment, vegetation and zonation. The spatial structures of these infauna were analyzed using multivariate statistical techniques such as TWINSPAN (Two Way Indicator Species Analysis) and CANOCO (Canonical Community Ordination) programs. Eighteen families of Polychaete were identified and densities ranged from 802 to 27,200 inds. m-2 with four dominant families namely: Nereidae represented by two species of Nereis, Syllidae by five genera of Brania, Oxegone, Pionosyllis,Sphaerosyllis and Typosyllis, Spionidae with Scolelepis and Ophelidae by Armandia lanceolata. The classification and ordination analyses based on the strong granulometry gradient and other environmental factors yielded the following three spatial communities: G-I, comprising of stations PI to P7, which were generally of sandy sediments at the outer zone (seaward), G-II, with muddy sediments (P8 to P12) at the inner zone (landward) and G-III, the riverine mangrove community with sampling sites (P 13 to PI 5) located separately. The community structure of G-I was observed to be most diverse for the Polychaete families compared with G-II and G-III communities.