Effects of sulphur type and concentration on growth performance, body composition and resistance of juvenile sea cucumber ( Apostichopus japonicus ) subjected to air and low salinity exposure stressors

Abstract

Supplementation effect of sulphur type and concentration on survival, growth and stress resistance of sea cucumber has not been known. Two‐way {2 type sulphur [liquid type (LTS) and nano‐powder type (NTS)] ×5 sulphur concentrations (25, 50, 100, 250 and 500 ppm)} ANOVA design was applied. LTS and NTS were included in the control (Con) diet at five sulphur concentrations instead of equal amount of water and cellulose, referred to as the LTS25, LTS50, LTS100, LTS250 and LTS500, and NTS25, NTS50, NTS100, NTS250 and NTS500 diets, respectively. Sea cucumbers were fed with triplicate groups of each diet for 8 weeks. After 8‐week feeding trial, sea cucumbers were exposed to 30‐h air and 12‐h low salinity exposure stressors and cumulative mortality was monitored. Survival was not affected by either sulphur type or sulphur concentration. Weight gain of sea cucumber was affected by both sulphur type and concentration. Sea cucumber fed all NTS diets except for the NTS25 diet achieved better weight gain than that fed the Con and all LTS diets. Chemical composition of sea cucumber was not affected by either dietary sulphur type or sulphur concentration. The cumulative mortality of sea cucumber was affected by both sulphur type and concentration after the 30‐h air and 12‐h low salinity exposure stressors. In conclusion, NTS was more effective than LTS to improve growth and lower mortality of sea cucumber subjected to the 30‐h air and 12‐h low salinity exposures. The greatest weight gain and resistance were obtained in sea cucumber fed the NTS500 diet.