Capturing of pearl oyster spats, Pinctada imbricata (Rodling 1798), with artificial collectors in the Gulf of Cariaco, Venezuela

We estimated the abundance of spats of Pinctada imbricata in Turpialito (Go lfo de Cariaco, Venezuela) by analyzing the monthly catch in two artificial substrates, 8 and 21 m deep, between March 30, 1993 and May 30, 1994. We r elated environmental factors and spat abundance at both depths. Juveniles w ere observed during most of the period. The highest number of individuals w as caught at 8 m (6 to 1176 juveniles caught monthly per 30 x 60 cm collect or) and the lowest was caught at 21 m (from 21 to 163 juveniles caught mont hly per 30 x 60 cm collector). The models established by multiple analyses did not predict environmental control over the reproduction of P. imbricata . When we increased variability given by depth, we were able to build model s in which the availability of food (abundance of microalgae and particulat ed organic material) was the predictive environmental factor. This suggests an association of larvae in the water column where food is available. The results show a continuous and acceptable catch of juveniles in artificial c ollectors designed for aquaculture activities, although we observed much va riation in the size of the juveniles that we caught, with a greater proport ion of small sizes (from 4 to 7 mm). We thus recommend shallow waters (3 to 8 m) and a longer period (1.5 to 2 months) between one catch and the next, in order to maximize the production of spats of P. imbricata in aquacultur e activities in the Golfo de Cariaco.