Availability of juveniles from natural sources of the oyster Pteria colymbus (Bivalvia : Pteriidae) in the Gulf of Cariaco, Venezuela

We examined the spat availability the oyster Pteria colymbus at 6-8 and 19- 21 m depths for 15 months (March 1993-June 1994) in Turpialito, Golfo de Ca riaco, Venezuela. Spats were trapped using artificial collectors (plastic f ilaments in bags, 30 x 60 mm), suspended from a long line. Each collector w as replaced by a replica monthly to analyse abundance, shell dimension and mass of El colymbus. Intraweekly, the temperature, salinity, oxygen and foo d availability (Chlorophyll a, total seston, organic and inorganic seston) were determinated. There is juvenile recruitment all year, suggesting conti nuous reproduction. Spat counts were higher at 6-8 m (generally 50-230 juve niles per collector) with peaks in August and December 1993 (April and June 93 at 19-21 m). The length-weigh mass relation was higher at 19-21 m, sugg esting greater food availability because of lower organism density (includi ng P. colymbus) and a greater water flux. Phytoplanktonic abundance and tem perature were correlated (r(2)=0.38) with juvenile abundanc; this relations hip and the association of juvenile abundance with higher temperature and C hlorophyll a levels, suggest that spat abundance was higher at the beginnin g of the water stratification period, when phytoplankton biomass is high.