Abstract

Overfished queen conch stocks in the Caribbean and Florida may be replenished with the release of batchery-reared juveniles. In past wild stock enhancement studies, it was found that the thin shells of the batchery-reared juvenile queen conch caused a large number of mortalities. Two factors determined to play a role in the shell morphology of the juvenile conch include stocking density and tank substrate. Experiments were designed to test differences in growth rate, shell weight to meat weight ratio, shell strength, survival, and burying of juvenile queen conch between different densities and substrates. Stocking densities were 20, 50, 75, 200 and 400 conch/m2 and the tank substrates included crushed coral aragonite, aragonite chips, and plastic liner. Consistent with previous research, juvenile conch grown in lower stocking densities statistically grew faster in shell length and animal weight than conch grown in higher densities. However, there were no statistical differences in growth rates between conch grown in 200 and 400 conch/m2. Conch grown on croshed coral aragonite grew significantly faster than conch grown on plastic liner but at similar rates to conch grown on aragonite chips. Preliminary data suggests that there are no significant differences in shell weight to meat weight ratios or shell strength between conch grown in different densities. Survival was lowest in conch grown in high stocking densities and on plastic liner. Burying occurred more frequently with conch stocked at high densities. In order to increase growth rate, to lower batchery costs, and increase shell strength to enhance the chance of survival after release into the wild, it is recommended that juvenile queen conch be grown at a stocking density of 75 conch/m2 on crushed coral aragonite.

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