A preliminary survey of the brittle star (class ophiuroidea) population in Shallow Intertidal Waters of Talicud Island, Davao Gulf /
Roosevelt T. Itum
- 2002
- 36 leaves
Thesis (BS Biology) -- University of the Philippines Mindanao, 2002
Ophiuroid populations in Talicud Island, Davao Gulf were surveyed to determine the species present, their classification, their habitat, and their distribution. Sampling using the modified belt-transect method (English et.al., 1997) was done only in the shallow intertidal areas (Stations 1 to 4). The reef sites (Stations 5 to 8) were surveyed only for taxonomic collection. A total of 5 species namely, Ophiocoma sp. A, Ophiocoma sp. B, Ophiomastix janualis, Ophiomastix sp. and Ophiarachna incrassate (Lamarck), were collected. All belonged to Family Ophiocomidae, except for the latter, which belonged to Family Ophiodermatidae. The two (2) Ophiocoma species were collected in the shallow areas, while the Ophiomastix and Ophiarachma species were collected from the reef areas. The high abundance of ophiuroids in the eastern side of the island (Stations 1 and 4) could be triggered by the northeast monsoon. The high correlation values in Stations 3 and 4 could be explained by the support of seagrass on microbenthic invertebrates by providing habitat for food gathering and reproduction. Assumingg the limitations and conditions on daytime sampling and months of northeast monsoon, and supported by high correlation, it was concluded that the distribution of intertidal ophiuroids depend on seagrass percentage cover. Thus, one of the factor that could account for ophiuroid distribution in the intertidal area is habitat preference