Free-Living Marine Nematodes in the Intertidal Area of Davao Gulf, Philippines

Abstract

The Philippines, whose waters comprise part of the Coral Triangle, a geographical area considered the global center of biodiversity, has one of the most diverse marine ecosystems in the world yet its marine nematode communities have not been extensively described. This scenario motivates us to address the paucity of taxonomic information in the region on nematodes as important biological drivers of nutrient recycling. The current study is a preliminary survey of free-living marine nematodes mainly from two sites (Punta Biao and Cinco) in Davao Gulf, Southern Philippines. Punta Biao has generally sandy substrate with seagrass beds that act as nursery grounds for fishes and sink for pollutants. On the other hand, Cinco is a coral beach resort developed for tourism. Six samples were randomly collected from each site. Preliminary qualitative results showed diverse fauna belonging to Orders Monhysterida, Chromadorida, Enoplida, and Dorylaimida. A total of 14 families and 34 genera, dominated by Daptonema, were identified to date from the coral beach habitat (Cinco) while 14 families and 22 genera, dominated by Retrotheristus, were identified from sandy seagrass beds (Punta Biao). For other stations sampled, the number of nematode genera recorded was 22 (Cuabo river mouth) and 8 (Baybay beach). Initial characterization of new marine nematode species is in progress.