Spat Collection and Experimental Culture of the Atlantic Pearl Oyster, Pinctada imbricata (Bivalvia: Pteriidae), under Suspended Conditions in the Caribbean

Abstract

Several suspended culture experiments of the Atlantic Pearl oyster, Pinctada imbricata, were carried out in the Colombian Caribbean. Seed was collected at two seasons of the year (rainy and dry) using onion bags collectors. Shell growth and survival of the oysters, as well as frequency and size of predators, were evaluated under different stocking densities (10, 20, 30, and 40% coverage of the bottom of the net), culture systems (pearl nets and pocket nets), seasons (rainy and dry), and depths (4 and 9 m). A greater amount of P. imbricata spat was collected during the dry season (297 ind./m2) than in the rainy season (72 ind./m2). Density influenced significantly the growth of P. imbricata but not its survival. The highest antero-posterior measure (APM) values appeared at lower densities (10 and 20% bottom coverage). Growth and survival values of the pearl oysters were greater in pocket nets than in pearl nets. Culture season did not affect the survival of the oysters but their growth was greater in the dry season than in the rainy season. Culture depth influenced oyster growth but not their survival, with recorded shell APM being greater at 9 m than at 4 m. The following predators: Cymatiidae, Portunidae, Majidae, and Xanthidae were found inside the culture nets. Highest mortality values of the pearl oysters coincided with high frequency and/or size of predators. Frequency of cymatids was higher during the rainy season and in pearl nets with high oyster density. Xantids appeared mostly in pocket nets and majids during the dry season.