Evaluation of the growth and survival rate of the Caribbean Sea cucumber, Isostichopus badionotus (Selenka, 1867), early juveniles produced in captivity

Abstract

Isostichopus badionotus is a new commercially important sea cucumber in the Caribbean that has rapidly shown signs of overexploitation. There is no information on the growth and survival rates for wild or hatchery‐produced early juveniles. Hatchery production and determination of juvenile growth rates are essential for future aquaculture efforts for this species. In this study, daily growth rate (GR), specific growth rate (SGR), weight gain (WG), survival rate (SR), and weight–length relation (WLR) were evaluated using small (0.01 g) and large (0.25 g) hatchery‐produced early juveniles under laboratory conditions. Growth was rapid compared to other cultured sea cucumber species; maximal values of SGR and WG were obtained for small juveniles (4.58%/day and 2,191%, respectively), while maximal GR and SR were obtained for large juveniles (0.29 mm/day and 99.17%, respectively). A wide range of sizes was evident at the end of each trial. The WLR of small and large juveniles fit with a negative allometric growth trend. This study highlights the potential production of I. badionotus as early juvenile stages withstand hatchery handling well and exhibit a high SR, reaching commonly released mean sizes (>0.7 g and 25 mm) after almost 3 months (120 days postfertilization).

Comparative Transcriptomes of the Body Wall of Wild and Farmed Sea Cucumber Isostichopus badionotus

“…Studies on farming of I. badionotus are ongoing [ 9 , 10 ]. However, as with many sea cucumber species [ 8 , 20 , 31 , 32 ], rearing I. badionotus in culture has proved problematic with development and growth being variable and slow.…”

“…The diet offered to farmed I. badionotus was formulated per present knowledge of their requirements [ 8 , 9 , 10 ]. However, it cannot be excluded that important, yet unidentified nutrients or micronutrients were missing or deficient in the food.…”

“…Early juveniles were transferred to fresh fiberglass tanks (see above) for subsequent growth. They were fed a mix of algae enriched with Algamac ® (Aquafauna Bio-Marine, Hawthorne, CA, USA), and supplemented with periodic additions of live and concentrated diatoms, following published protocols [ 8 , 9 , 10 ]. First generation individuals of approximately two years of age were collected for the transcriptome analysis; these were called “farmed” sea cucumbers (5–7 cm, 17–43 g) ( Supplementary Table S1 ).…”

“…Farming of I. badionotus could in part alleviate this problem by offering a readily available commercial source of mature sea cucumbers or alternatively by providing seed animals for restocking and regeneration of wild populations. Cultivation studies are ongoing [ 8 , 9 , 10 ]. In these, animals are kept in indoor fiberglass tanks in a closed recirculating system with a temperature maintained at a range between 24–26 °C and a 13:11 (light:dark) photoperiod [ 8 ].…”

“…and Macrocystis sp., with fatty acid-rich supplements [ 8 ]. Under these conditions most I. badionotus survive, go through larval development, and slowly grow and mature as juveniles and adults [ 8 , 9 , 10 ].…”