Seed collection and experimental culture of the pen shell Pinna carnea Gmelin, 1791 (Bivalvia: Pinnidae) in the Tayrona National Natural Park, Colombian Caribbean

Abstract

Spat collection and growth experiments were carried out between September/1994 and November/1995 with the purpose of determining the biological and technical feasibility of culturing the pen shell Pinna carnea (Mollusca:Bivalvia) in the Santa Marta region.  A total of 125 seeds/Collector was obtained using artificial collectors of the <<curtain>> type held in the water for 10 weeks at 4 and 10 m of depth.  The seeds obtained were cultured on <pearl nets> held at 9m and at two densities, 10 and 20% of the net bottom coverage.  Shell growth, survival, and number of predators per pearl net were assessed monthly, along with data on water temperature, salinity, and concentrations of total (MPT) and organic (MOP) seston.  After 11 months of culture, the bivalves attained average lengths of 167.5 and 156.5 mm at densities of 10 and 20% respectively.  No significant differences in growth or survival were detected between treatments.  Significant negative correlations were found between growth rates, their size (length) and water temperature, and positive with salinity and MOP in the water.  Mortality of P. carnea was positively and significantly correlated with the number and sizes of both cymatid gastropods and crabs (portunid and xantid).  The pen shell has positive features for culture in the area:  the seed is relatively abundant and essay to collect, size and growth rate are high and despite early survival is depleted by predators, its vulnerability is low once the shells attain 100mm in length.