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Email the author (Login required) Growth, survival and environmental effects on three cohorts of the pearl oyster Pinctada imbricata, under suspended culture at Cariaco Gulf, Venezuela
DOI: https://doi.org/10.3856/vol44-issue1-fulltext-10
Abstract
The growth and survival of individuals of the pearl oyster Pinctada imbricata (spats of 16-24 mm antero-posterior shell length) belonging to three different cohorts (CI, CII and CIII) were evaluated in suspended culture at Cariaco Gulf, Venezuela, during three contrasting environmental periods. The cultures were made in pearl nets suspended at 2-3 m from a long line. Cohort CI was cultured from October 2007 to April 2008 (covering the period of stratification and upwelling waters of the area), the CII from June 2008 to February 2009 (dominated by the remission of the coastal upwelling and the start of the same) and the CIII from February 2009 to July 2009 (coastal upwelling period). Monthly determinations included the number of gastropods of the genus Cymatium spp., recruited in the culture baskets, shell length, oyster survival, and mass of the shell, muscle and other tissues, as well as, the fouling mass on the shells. Water temperature was continuously recorded, while salinity, chlorophyll, and dissolved oxygen seston biweekly. Results obtained from the different cohorts studied suggest that the variables that significantly affect growth rates were temperature and food availability, whereas the survival rate was inversely associated with incidence of Cymatium spp. The highest rates of growth and survival were observed in individuals of P. imbricata that were grown in the influenced by coastal upwelling period (CIII). This evidence suggests that at this period characterized by higher availability of phytoplanktonic food and low temperatures is the most suitable for the cultivation of the P. imbricata in the southeastern Caribbean
