Habitat and reproductive biology of angelwings, Pholas orientalis (Gmelin)

The angelwing, Pholas orientalis (Gmelin) is indigenous to the coastal wate rs of the Provinces of Negros Occidental, Capiz and Iloilo in Central Phili ppines. They burrow into either muddy sand substratum in the littoral zone or compact bluish-gray muddy sand in the sub-littoral zone. They burrow to a depth of over 0.3 m and once extracted can never return. Specimens studie d were invariably dioecious without apparent sexual dimorphism. Sexual matu rity is reached at a shell length of 59 mm and 64 mm for males and females respectively. Each sexually mature individual possesses a gonad that is imb edded in the ventral side of the viscera. Both male and female gonads are a rborescent in form and have the same coloration. Samples collected from Bar otac Nuevo, Iloilo showed that the peak of spawning occurred from June thro ugh October and gametogenesis started in October.