Aquaculture America 2024

February 18 - 21, 2024

San Antonio, Texas

EARLY LIFE CYCLE AND EFFECTS OF MICROALGAL DIETS ON LARVAL DEVELOPMENT OF WARTY SEA CUCUMBER Apostichopus parvimensis

Yuanzi Huo*, Kevin Stuart, Mark Drawbridge

 

Hubbs-SeaWorld Research Institute, 2595 Ingraham Street, San Diego, CA .

yhuo@hswri.org

 



 The high commercial value (up to $300–500 /kg dried ) and the increasing demand for sea cucumbers has promoted over-exploitation in the wild, which has resulted in the collapse of natural stocks and is likely negatively impacting vulnerable benthic ecosystems. Overfishing is encouraging the development of aquaculture technologies for sea cucumbers to meet the market demand and to create new economic opportunities . Warty sea cucumber (WSC) Apostichopus parvimensis is one commercial species along the Pacific coast of the U.S .   Wild populations of WSC  have reached levels of concern due to overfishing , and  it is now  listed on the International Union for the Conservation of Nature Red List of Threatened Species.

 Adult WSCs  were collected  off the coast of San Diego  and  held under  ambient conditions in flow through seawater tanks . Spawning induction trials were conducted at the end of  the natural spawning season .  Larval stages and survival rates were  recorded, and  the effects of single and multiple combinations of microalgae species were evaluated in relation to larval performance . T he spawning rate  (spawned/total) was 0-55.6 % , and the  fertilization rate was 85.15±1.71 %.  The gastrula stage was reached between 36 h and 3 days post-fertilization (dpf ), and early, mid and late auricularia stages were reached  at 3, 8, 12  dpf  with  a mean length of 581.15±98.34 , 862.72±84.84 , and 663.86±59.94 μm , respectively. Late auricularia larv ae became non-feeding doliolaria  at  15  dpf with  a  reduced  mean length to 441.01±16.92 μm , and  reached  the pentactula stage at a mean length of 483.00±11.39  μm at 17 dpf. The survival rate decreased to 24.17±2.89 % at 19 dpf, at which time  the doliolaria and pentactula  stages accounted for 28.07 % and 8.77 % of the survivors, respectively .  During the first 7 days of culture larval mortality was 50%. The survival rate of larvae fed with different diets was not significantly differen t, but  larvae developed faster when fed with Rhodomonas sp. , and  a  mixture of Rhodomonas sp.+ Tisochrysis lutea than other diet groups.  The results of this study will help establish hatchery production protocols for A. parvimensis  and aid in the further development of the aquaculture of this species.