Some Aspect on the Biology of Pen Shell Atrina Pectinata (Linneaus, 1767) In Coastal Waters of Maqueda Bay, Philippines

Abstract

A Total of 379 pen shells Atrinapectinata were collected from February 2017 to January 2018 in the coastal waters of Maqueda Bay. Measurement and analysis of length and weight were done using FiSAT software. Population parameters were assessed to evaluate the stock status which includes the asymptotic length (L∞) and growth coefficient (K) to be 34.65 cm, 0.77 year−1 respectively. Specimens of A. pectinata reached a mean length of 20.98 cm. Length-weight relationship resulted to “negative allometric” 0.0462L2.6533 R2 = 0.7823; signifying pen shells growth was faster in length than on weight. The recruitment pattern was continuous over the year with one major peak during rainy season (July). In addition, the highest catch based on collected sampling date catch was during summer, which suggest as the peak season of the species in the area. Furthermore, the average catch annually of hookah diver was 17.69208. Higher condition index was recorded from April to May, September and January, indicating the high quality of pen shell meat and is recommended as the best period to harvest pen shell whereas June to August and October to December can be concluded as the spawning period of the pen shell and the ideal period to institute close season. Further analysis revealed that the pen shell was nearly facing overexploitation with the exploitation rate (E = 0.46) mainly due to lack of a minimum limit size and also due to an increase in the harvesting effort. The estimated total mortality (Z), natural mortality (M) and fishing mortality (F); 1.36 year−1, 1.01year−1 and 0.62 year−1, respectively. Using the mentioned (Z), (M), (F) and (E), the total population resulted to 84725.7 suggesting that half of the population has been exploited due to overfishing