Holothuria floridana is one of the two most economically important sea cucumber species in the Yucatan Peninsula, resulting in severe overexploitation, reduced wild populations, and the permanent closure of the fishery. Given this scenario, aquaculture could be a strategy that would allow its controlled production for commercial purposes and restocking, for which it is necessary to generate basic information about its reproductive biology to develop farming protocols. In this sense, this work aimed to study the early stages of its life cycle and its effect on aquacultural biotechnology.
Broodstock of H. floridana were captured off the coast of Yucatan, Mexico, and moved to the Cinvestav marine station in Telchac Puerto, Yuc., where thermal shock-induced spawning and artificial fertilization were performed. Egg samples were incubated under controlled conditions to document their embryonic and larval development.
Their eggs had a diameter of 394 ± 16 μm (n = 20; mean ± SD). After fertilization, they sediment and adhere to the substrate or body of the breeders using a gelatinous capsule that covers them. This study confirmed that H. floridana presents a direct lecithotrophic non-pelagic embryonic development inside the egg as a vitellaria larva, which hatches as a pentactula four days after fertilization, reaching the early juvenile stage seven days after fertilization and completes its development as a juvenile suitable for transfer to external culture systems at 60 days.
This embryonic development strategy of H. floridana gives it technological and economic advantages over planktotrophic species with free-swimming larvae and larval cycles of around 20 days since, in addition to not requiring incubators and food during larval development, the pentactula larvae are obtained in just four days, when begins the feeding with benthic microalgae and complemented with supplementary food after seven days. Its cultivation represents lower infrastructure costs since it does not demand a significant area in the hatchery for the cultivation of live food, in addition to requiring a single type of pond where the entire cycle takes place, from incubation to the growth of seedlings, privileging the surface over the volume, including mesh substrates in the tanks to increase the feeding areas and the stocking density.
These results indicate that the larval culture of H. floridana has lower technological and infrastructure requirements than species with planktotrophic larvae, so it could be considered a model organism for the development of aquaculture technologies for holothurids in the western Atlantic, either for commercial purposes or for the restoration of wild populations using simple and sustainable farming strategies.