Controlled spawning and rearing of the sea cucumber, Parastichopus tremulus

The red sea cucumber, Parastichopus tremulus, a cold water species with commercial potential, has recently attracted attention for wild harvest as well as for potential use in integrated multi-trophic aquaculture in Scandinavian countries. Overharvesting has put natural stocks of sea cucumbers at risk in several countries. Our goal was to develop a rearing protocol for P. tremulus to enable sustainable production of this species. This study presents results from spawning and larval rearing conducted in both Norway (NO) and Sweden (SWE) during May-August 2019. We describe spawning induction and behavior, fertilization success, embryonic and auricularia larval development rate for this species under laboratory conditions. The larvae were fed a mixture of three species of live microalgae (SWE) and algal paste (NO). Larval development rate and survival were monitored at four different temperatures (7, 10, 13, and 16 degrees C). Results showed faster development with increasing temperature. Daily food consumption rate was highest at the highest temperature. The combined effects of temperature and food availability on survival were investigated for the same four temperatures and three different feed concentrations. Only food availability affected the mortality rate, with the highest mortality in the low feeding regime of 1,000-2,000 cells ml(-1) day(-1).

Automated summary

The study aimed to develop a rearing protocol for the red sea cucumber to enable sustainable production. Results from spawning and larval rearing conducted in Norway and Sweden showed that temperature and food availability have significant effects on survival rate.