Abstract

Larval development and growth were evaluated for larvae of the fighting conch Strombus pugilis. Temperature culture was 29 +- l°C, the veligers were reared at a density of 200 larvae per litre, into 4-litre tanks. Larvae were fed Terraselmis suecica at a concentration of 1,000 cells/ml. Five experimental cultures were mounted, four were irradiated per 10 minutes dialy and an control group without irradiation, each one with two replicates. Culture 1 were irradiated per seven days, Culture 2 per 14 days, Culture 3 per 21 days and Culture 4 per 28 days. Larval development in irradiated larvae was better that control group. The best settlement rate was observed in Culture 3, where 30% of the larvae began settlement on the 25 days. The settlement began to 28 days in Culture I with 33%. in Culture 2 with 35%, in Culture 4 with 30% and the settlement began in the control group on 29 days with 31% of the larvae. In growth, the maximum shell length was also observed in the larvae of Culture 3 with a mean of 1 312 +- 7.98 um (n = 30) at 30 days versus l 080 +- 10.75 um (n = 30) of the control group.

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