A recent breakthrough at FAU Harbor Branch offers promising advancements in conch aquaculture by potentially eliminating the need for wild-sourced egg masses to supply hatcheries. Sixteen milk conch (Macrostrombus costatus) broodstock, consisting of nine females and seven males, were provided with a sand substrate, flow-through seawater, and a diet predominantly consisting of diatom-rich algal turf scrubbers (Fig. 1). These scrubbers were cultured using nutrient-rich wastewater from an Integrated Multitrophic Aquaculture system. This diet has been one of the contributing factors that resulted in reliable and prolific spawning, compared to previous studies that used formulated feeds. Between April to September 2024 (24 weeks) this population produced an average of 9.2 egg masses per week, totaling 221 egg masses, of which 76% had viable offspring.
The listing of the queen conch, Aliger gigas as threatened on the Endangered Species Act has underscored the need for a recovery plan for this ecologically and economically important species. As a close relative of A. gigas, the milk conch (M. costatus) serves a similar ecological role and is harvested in certain Caribbean regions. This proximity allows milk conch to be used as a surrogate species to test the viability of establishing a captive queen conch breeding population, thereby reducing the dependence on wild egg mass collection for restoration hatcheries. This study has shown that a key to a reliable captive conch breeding program is the use of algal turf scrubbers as the primary nutritional component. Future studies with queen conch adults should use this food source to encourage egg laying in captivity for use in restoration aquaculture.