Diurnal sheltering behavior of hatchery-propagated long-spined urchins (Diadema antillarum): a re-examination following husbandry refinements

The functional loss of herbivory on Caribbean coral reefs following an epizootic-driven die-off of the long-spined urchin (Diadema antillarum) in the 1980s and its lack of recovery has inspired efforts to re-establish an ecologically viable population throughout the region. An area of focus is to develop scalable methods for producing D. antillarum through aquaculture from gametes for release onto coral reefs. We had earlier observed that aquaculture-produced D. antillarum lacked the strong diurnal sheltering behavior exhibited by wild individuals. Based upon those findings, subsequent cohorts of aquaculture-produced individuals were therefore maintained under a natural diurnal cycle of UV-filtered sunlight and provided ample access to structure that mimicked its natural shelter. An examination of the sheltering behavior of D. antillarum from one of these cohorts found the pronounced diurnal sheltering behavior typical of wild individuals. This observation underscores the potential that the behavioral deficit observed in earlier hatchery-propagated D. antillarum can be mediated and ecologically functional individuals can be produced through this aquaculture process.