Effects of feed supplemented with probiotics on the culture of sea cucumber Apostichopus japonicus

In this study, mixed feed (MF), a mixture of probiotics and formulated feed, were fed to sea cucumbers Apostichopus japonicus. The specific growth rate (SGR) and weight gain (WG) of sea cucumbers, the crude protein content (CPC) and protease activity (PA) in different parts of their intestines, feed conversion ratio (FCR) and protein efficiency ratio (PER), as well as the water quality of the culture water, were determined and compared with that of the control (formulated feed, FF) diet. The results showed that WG and PER of sea cucumbers were significantly (p < .05) higher in MF groups compared with FF groups. The SGR and PA in the intestines of MF groups increased significantly (p < .01) compared with FF groups. The CPC in the intestines of MF individuals was far lower (p < .01) than FF ones. The FCR was significantly (p < .05) lower in MF groups than the control groups. The culture water in MF groups showed lower (p < .05) levels of ammonia–nitrogen and nitrite–nitrogen than in the other groups. These results revealed that probiotics enhanced growth performance, PER and PA, and improved water quality in culture aquariums. The addition of probiotics to feed was beneficial for sea cucumbers and maybe good for other aquaculture animals.