Survival and growth of the sea cucumber Holothuria leucospilota Brandt: a comparison between suspended and bottom cultures in a subtropical fish farm during summer

摘要

The feasibility of co-culturing the sea cucumber Holothuria leucospilota Brandt in a subtropical fish farm was investigated in a field study. Sea cucumbers were cultured in the fish farm in cages suspended at 4?m deep (suspended culture) and directly on the seafloor (bottom culture). The survival and growth of the sea cucumbers were monitored twice during the 3-month, summer experimental period (May 26–August 14, 2010). Results showed that the suspension-cultured sea cucumbers exhibited excellent survival rate (100%) during the whole study period. There also occurred no mortality in the bottom-cultured sea cucumbers during the first culture period (May 26–July 13); but all these died from anoxia caused by water column stratification during the second culture period (July 14–August 14). The specific growth rate of the bottom-cultured sea cucumbers (1.05?±?0.21?%?day?1) was nearly double that of the suspended culture animals (0.57?±?0.21?%?day?1) during the first culture period, and the growth rates of the suspended culture sea cucumbers in the second culture periods (0.46?±?0.24?%?day?1) was only a little lower than that of the first period. The sea cucumbers H. leucospilota could ingest and assimilate sediment with high organic matter content with an average assimilation efficiency of 14.9?±?3.9%. This study indicated that fish farm detritus can be effectively used as a food source for the sea cucumber and that it can be turned into a valuable secondary crop in the form of the sea cucumber biomass.