Population Dynamics of the Hiant Venus Marcia hiantina (Lamarck, 1818) (Mollusca: Bivalvia, Veneridae) Gleaned in Banate Bay, Iloilo, Western Visayas, Philippines


by: Annabelle G.C. del Norte-Campos, Switzel L. Lapara, Kris Angeli S. Sanchez


Growth, recruitment, mortality, and exploitation of the hiant venus Marcia hiantina (formerly Katelysia hiantina) (Mollusca, Pelecypoda: Veneridae) locally known as “punaw”, collected from June 2018 to May 2019 from catches of gleaners in Banate Bay, Iloilo were analyzed using the FiSAT software. Smallest and largest sizes gathered during this period were 9.0 and 61.0 mm shell height (SH), respectively. Von Bertalanffy growth parameters derived for the species using ELEFAN I are an asymptotic shell height (SH∞) of 66.63 mm and growth coefficient(K) of 1.05 yr-1. These correspond to a growth performance index (ø’) of 3.67, comparable with values for other bivalves. Based on the Bhattacharya analysis, a growth rate of 0.166 mm day-1 was estimated and based on this, the species has a lifespan of approximately 1 year. Using ELEFAN II, a total mortality, Z of 4.52 yr -1 was estimated from a length-converted catch curve. From an averaged M/K value from the literature of (1.51) multiplied by this species’ own K, a value of natural mortality, M = 1.59 yr-1 was derived, which then results to a fishing mortality (F) of 2.93 yr -1. Recruitment pattern was bimodal, supported closely by the species’ reproductive biology which has 2 peaks of spawning observed in July and January. Given the species’ overexploited status (E = 0.65), managing the stocks by prohibiting the collection of sizes less than the minimum size at sexual maturity (27 mm) and closing the fishery at least during the peak spawning month (July) is necessary and recommendable.

Keywords: Marcia hiantina, hiant venus, population dynamics, gleaning, Banate Bay