Population dynamic of pearl oyster pinctada radiata in 2 habitats of Lavan Island, Persian Gulf

As pearling has been banned since 2006 in Persian Gulf¡ growth and mortality rate of Mohar pearl oyster in its old habitats was surveyed in present research. For early survey and identification of habitats of Mohar pearl oyster Pinctada radiata¡ primary sea tours in coastal waters of Lavan Island¡ were done. Two habitats were identified and sampled seasonally from autumn 2011 to summer 2012¡ to investigate Pinctada radiata stock condition. Belt transects and random quadrates method was used in this sampling. Infinity length¡ L∞¡ in Lavan No. 1 (Dardoor) and Lavan No. 2 (Hedabad) habitats was 89.16 and 87.68 mm. Growth constant¡ K¡ estimated 0.34 and 0.44 year-1in that two habitats. The amount of t0 for oysters in Dardoor and Hedabad habitats was -0.36 and -0.28 year and tmax was estimated equal to 8.46 and 6.54 year respectively. Natural mortality constant¡ M¡ was 0.63 and 0.75 year-1 respectively. Analyses of growth constant¡ K¡ revealed that this figure has decrease in these habitats in recent years. Investigation of recruitment plots indicated semi continuous pattern of recruitment in pearl oysters¡ demonstrating that reproduction occurs in almost throughout the year although two peaks of reproduction were observed in summer and winter.