Hydrogen peroxide induced metamorphosis of queen conch, Strombus gigas: Tests at the commercial scale

The use of natural extracts in production scale culture processes has been problematic because of the temporal and spatial variability inherent in the active constituents of the extracts and the high cost associated with their preparation. Readily available, low cost alternatives to the natural extracts are needed. In the current study, the use of hydrogen peroxide as an alternative to aqueous extracts of the red alga Laurencia poitei, the current commercial inducer of queen conch (Strombus gigas) metamorphosis, was examined. Exposure of larval conch to 50 mu M hydrogen peroxide for 10 h in both small scale and production scale assays induced full larval metamorphosis. The percent metamorphosis induced by hydrogen peroxide was not significantly different from that induced by L. poitei extract. In addition, the growth of the newly set juveniles induced by hydrogen peroxide was not significantly different from those induced by the L. poitei extract. Thus, hydrogen peroxide provides a low cost and readily available alternative to the natural cue for the commercial scale induction of metamorphosis in queen conch; it also eliminates much of the variability typically associated with the use of the natural inducer.