Refinement of sea urchin husbandry is crucial for maintaining a healthy population for both commercial aquaculture and research. It is well established that wild populations of Lytechinus variegatus undergo multiple spawning events from early spring through late summer. The purpose of this experiment is to emulate a repetitive spawning cycle to determine if regimented spawning in culture is associated with a significant change in reproductive outcomes.
Seventy-two adult L. variegatus (ca. 50-g) were collected from St. Joseph Bay, FL. The sea urchins were chemically induced to spawn upon return to the University of Alabama at Birmingham to determine sex as well as to void the gonad and establish a baseline. Following identification, sea urchins were assigned to either the monthly or bimonthly spawning treatment. The sea urchins were kept on a recirculating aquaculture system (RAS) to acclimate prior to beginning a formulated feed diet. Spawning was induced to sea urchins according to treatment each month on or around the new moon.
Data collected during each spawn included sea urchin diameter, height, weight, mass of gametes produced, and density of eggs produced for female sea urchins. Larvae potential was also recorded through tracking the development of larvae over 3-5 days. Preliminary results indicate that more frequent spawning regimens (once a month) may lead to increased gamete output for some female sea urchins (Fig. 1.) while males may benefit more from every other month spawning regimes (Fig. 2).