Characteristics Of Bacteria And Enzyme Activities In Sea Cucumber Intestine

Culture of sea cucumber is one of the pillar industries in marine aquaculture.But the existing way of aquaculture is more extensive. The basic research is weak.The development of the industry faces difficulties. This kind of situation is moreobvious in the new bait and breeding way. There are many problems in theaquaculture of sea cucumber, such as natural bait production insufficient, lack ofsystemic in terms of nutrition research, excessive consumption of the waterresources and the energy, serious water pollution and aestivation. Explored thefeasibility of fermented bait and a scientific problem about the growth rate reducedduring recirculating aquaculture. Laid the theoretical foundation for therecirculating aquaculture. In order to ensure the healthy and sustainabledevelopment of sea cucumber aquaculture industry, service for the local economy.The test simulated conditions of sea cucumber aquaculture in the laboratory.Established sea cucumber farming systems. Tested the variation of water quality,four kinds of intestinal enzyme activities and bacterial numbers by feedingfermented bait and formulated diet, under the conditions of normal aquaculture andrecirculating aquaculture. Explored the changes under different conditions duringsea cucumber aquaculture. Laid the theoretical foundation for the recirculatingaquaculture.Fermented bait have effects on improving water quality under normalaquaculture condition. Ammonia concentration can maintain below0.05mg/L,nitrite concentration less than0.03mg/L, CODMnconcentration less than2.2mg/L,reactive phosphorus concentration below0.059mg/L. Maintained the stability ofwater quality in sea cucumber bond. The growth rate of feeding fermented bait ishigher than the growth rate of feeding formulated diet. Under condition ofrecirculating aquaculture, ammonia was maintained at0.015~0.03mg/L, nitriteconcentration was maintained at0.001~0.0025mg/L, CODMnmaintained at0.99~1.94mg/L, reactive phosphorus concentration varied from0.018mg/L to0.063mg/L. Water quality can be maintained in good condition. The water quality infermented bait pond is better, while the growth rate of sea cucumber slightly lower.Proved that the water quality was not the limit factor of the growth rate lower.Amylase, cellulase and alginase activities in the,sea cucumber intestine offeeding fermented bait are higher, while protease activity is lower. The purpose is to maintain more balanced enzymes. Compared to normal aquaculture andrecirculating aquaculture, intestinal enzymes activity is slightly lower, while thegrowth rate of sea cucumber slightly lower. Proved that the intestinal enzymeactivities were not the limiting factor of the growth rate lower.The bacterial numbers in the sea cucumber ponds of feeding fermented bait arehigher. Compared to normal aquaculture and recirculating aquaculture, the bacterialnumbers in the sea cucumber ponds and intestine substantially unchanged. Provedthat the bacterial numbers were not the limit factor of the growth rate lower.Compared with normal aquaculture, water quality can maintain in goodcondition. Intestinal enzyme activities are slightly lower. The bacterial numbers inthe sea cucumber ponds and intestine substantially unchanged. Showed that waterquality, intestinal enzyme activities and bacterial numbers were not the limitingfactors of the growth rate lower. The limiting factors of the growth rate always needto be found.