Pearl Oyster Pinctada Imbricata Research Articles

Culture potential of the pearl oyster ( Pinctada imbricata) from the Caribbean. : II. Spat collection, and growth and mortality in culture systems

Temporal variation in abundance of larvae and spat of the pearl oyster Pinctada imbricata was studied at several locations on the Colombian coast from May 1997 to June 1998. Larvae were sampled with bongo nets and spat were harvested from collectors at monthly intervals. Abundances of predators ( Cymatium gastropods, and portunid, xanthid and majiid crabs) were also recorded. A relationship between salinity, particulate organic matter and larvae abundance was observed, leading to peaks in abundance of spat on collectors some weeks later. Average catch rates of 10 spat collector −1 month −1, using collectors made of cheap easily accessible materials, indicate that availability of P. imbricata is sufficient to initiate and support aquaculture of this species. Growth and mortality rates of juveniles in three different culture systems at two densities (20% and 30%, i.e. percentage of available area covered by juveniles) showed that density within the same culture system had no effect on growth, but that growth differed significantly among the three culture systems. Growth in “bag” systems was lower than in boxes whereas growth in “suspended” and “bottom” boxes was similar and comparable to the growth of a natural population. The suspended boxes are the easiest to handle because they do not require SCUBA diving and so these systems are recommended.

Algunos eufausiaceos del Golfo de Paria, Golfo de Cariaco y Delta Orinoco al Oriente de Venezuela. (In English) : Legare J. E. H., 1961. Bol. Inst. Oceanogr., Univ. Oriente, Cumana, Venezuela. 1 (1): 131–148

We evaluated the efficiency of the sea urchins Lytechinus variegatus and Echinometra lucunter as a biocontrol of fouling on nets and on bivalve shell of the pearl oyster Pinctada imbricata during culture, using suspended pearl nets from long lines, located in Turpialito, Golfo de Cariaco, Venezuela, for 3 months. We established four treatments: nets with (1) two E. lucunter, (2) two L. variegatus, (3) one L. variegatus and one E. lucunter, and (4) without sea urchins. At end of the experiment, all sea urchins were alive and the pearl nets with the sea urchins had a significantly less dry mass of net fouling than nets without sea urchins. Although E. lucunter reduced the fouling on the nets by 45%, it did not reduced fouling on shells of the oysters. L. variegatus reduced fouling on nets by 74% and fouling on the shells by 71%. This work is the first report demonstrating the usefulness of sea urchins in controlling fouling in bivalve culture. We recommend the use of sea urchins to reduce net and shell fouling during the culture of tropical bivalves.