CHARACTERIZATION OF ORGANIC PARTICLES ASSOCIATED WITH RAPID GROWTH INJUVENILE WHITE SHRIMP, PENAEUS-VANNAMEI BOONE, REARED UNDER INTENSIVECULTURE CONDITIONS

Aquaculture ponds possess unique ecological characteristics which cont ribute significantly to the growth and survival of the target species. In this study, shrimp growth rates were monitored in microcosm tanks containing flow-through water with varying concentrations of organic p articles produced autochthonously in an intensive shrimp pond. Rapid g rowth occurred in unfiltered pond water with a mean particulate organi c carbon (POC) concentration of 6.98 mg/l over six sampling days. In c ontrast, slowest growth occurred in well water with a mean POC concent ration of 0.38 mg/l. Within the POC pool, as the percentage of living carbon increased, shrimp growth rates increased. Unfiltered pond water contained more than 45% living carbon, whereas well water had greater than 85% detrital carbon. Living biomass was dominated by pennate and centric diatoms, whereas contributions from bacteria and protozoans w ere minor. There was a highly significant linear relationship between shrimp growth and POC concentration (r2 = 0.895, p < 0.0001), although there appeared to be a minimum threshold concentration below which sh rimp growth was unaffected. Temporal variability in algal cell density (ACD) indicated a bloom and crash cycle, suggesting that the availabi lity of live algal cells to shrimp was sporadic. Further research on p ond ecology is needed in order to manipulate organic carbon pools to i mprove shrimp growth.