Study On Enteromorpha Prolifera And Cellulase In Feed Of Sea Cucumber(apostichopus Japonicus Selenka)

Apostichopus japonicas(Selenka) belongs to Apostichopus, Stichopodidae, Aspidochirotida, Echinodermata. It is distributed in the shallow sea of western north Pacific mainly,which is included the Russia’s eastern coast, the coast of the Korean peninsula and Japan, and China Bohai Sea and Yellow Sea. Since the 1980 s, sea cucumber aquaculture grows to a emerging industry in north China’s coastal aquaculture rapidly and become a northern local characteristics aquaculture industry and a new marine economic growth, with the breakthrough technology of artificial breeding of sea cucumber. With the unprecedented development of sea cucumber aquaculture, the feed is becoming an important factor in the development of sea cucumber aquaculture. Therefore, the increase of sea cucumber diet study has important implications for the development of sea cucumber aquaculture.In this paper, the Enteromorpha prolifera and cellulase were studied. The E. prolifera of different content,the cellulase of different content and three treatments of E. prolifera was contained in the feed of sea cucumber, and the effects of them on growth, digestion and non-specific immunity of juvenile sea cucumber(A. japonicus Selenka) was studied. It means to determine appropriate amount added and appropriate treatments in the feed, and purpose to to provide reference about enhancing the feed utilization and formulating efficient and reasonable diest of sea cucumber.Experiment 1:Effects of dietary Enteromorpha prolifera on growth, digestion and non-specific immunity of juvenile sea cucumber(Apostichopus japonicus Selenka)The experiment was conducted to investigate the effects of dietary Enteromorpha prolifera on growth, digestion and non-specific immunity of juvenile sea cucumber(Apostichopus japonicus Selenka). A total of 630 sea cucumbers with an average initial body weight of(1.44±0.01) g were fed with 6 practical diets according to a singlefactor design: a basal diet as the control diet supplemented with 0,5%, 10%, 15%, 20% and 25% E. prolifera for 49 days. There were 3 replicates per group with 35 sea cucumbers. The experiment results showed as follows:1) dietary E. prolifera had significant influence on specific growth rate(SGR) and feed conversion ratio(FCR)(P<0.05) and the highest SGR and lowest FCR of sea cucumbers were both found in the diets containing 20% E. prolifera, and the feed intake(FI) and survival rate(SR) were no significant in any diets(P>0.05);2) The apparent digestibility coefficient of dry matter(ADCd) and apparent digestibility coefficient of crude protein(ADCp) of diets were declined with the increasing content of E. prolifera(P<0.05).3) the diets containing 20% and 25% E. prolifera had significant influence on the amylase(AMS), the pepsin(PP) was raised with the increasing contents of E. prolifera,but had no significant influence(P>0.05).4) Dietary E. prolifera had significant influence on the superoxide dismutase(SOD) activity, and the highest was found in the diets containing 20% E. prolifera(P>0.05). The acid phosphatase(ACP) activity in the gut of sea cucumbers was no significant in any diets(P>0.05). It can be concluded that dietary E. prolifera can enhance the growth, amylase activity and non-specific immunity and decline feed conversion ratio of juvenile sea cucumber(Apostichopus japonicus Selenka). It compromises the indexes on growth, digestion and non-specific immunity of juvenile sea cucumber and suggests that the optimal addition of Enteromorpha prolifera in the diets of juvenile sea cucumber is 20%.Experiment 2:Effects of dietary cellulase on growth, digestion and non-specific immunity of juvenile sea cucumber(Apostichopus japonicus Selenka)The experiment was conducted to investigate the effects of dietary cellulase on growth, digestion and non-specific immunity of juvenile sea cucumber(Apostichopus japonicus Selenka). A total of 630 sea cucumbers with an average initial body weight of(1.44±0.01) g were fed with 6 practical diets according to a single factor design: a basal diet as the control diet supplemented with 0, 0.025%, 0.05%, 0.10%, 0.20% and 0.40% cellulase for 49 days. There were 3 replicates per group with 35 sea cucumbers. The experiment results showed as follows:1) dietary cellulase had significant influence on SGR and FCR(P<0.05) and the highest SGR and lowest FCR of sea cucumbers were both found in the diets containing 0.10% cellulase, and FI and SR were no significant in any diets(P>0.05); 2) The ADCd and ADCp of diets were raised and then declined with the increasing dosage of cellulase, and the highest of ADCd andADCp were both found in the diets containing 0.10% cellulase which was significantly higher than the control group(P<0.05), and the diet containing 0.40% cellulase had no significant influence on ADCd compared with control group(P>0.05), but had significant lower on ADCp than control group(P<0.05); 3) Dietary cellulase had significant influence on AMS in foregut, midgut and hindgut of sea cucumbers(P<0.05), and the diets containing 0.10%, 0.20% and 0.40% cellulase had significant influence on AMS in foregut, midgut and hindgut respectively(P<0.05). 4) The SOD activity and ACP activity in the gut of sea cucumbers when they were fed on diets containing 0.100% and 0.200% cellulase were significant higher than the control groups(P<0.05). It can be concluded that dietary cellulase can enhance the growth, digestibility, amylase activity and non-specific immunity and decline feed conversion ratio of juvenile sea cucumber(Apostichopus japonicus Selenka). It compromises the indexes on growth, digestion and non-specific immunity of juvenile sea cucumber and suggests that the optimal addition of cellulase in the diets of juvenile sea cucumber is 0.10%.Experiment 3:Effects of three treatments of Enteromorpha prolifera on growth, digestion and non-specific immunity of juvenile sea cucumber(Apostichopus japonicus Selenka)The experiment was conducted to investigate the effects of dietary three treatments of Enteromorpha prolifera on growth, digestion and non-specific immunity of juvenile sea cucumber(Apostichopus japonicus Selenka). A total of 420 juvenile sea cucumbers which the initial weight was(4.58±0.23) g were fed with 3 practical diets according to a single factor design: the diet contain with 20% three treatments[dry crushing(DC), dry crushing after cellulase treatment(DCC) and dry crushing after protease treatment(DCP)] of E. prolifera for 60 days. There were 3 replicates per group with 35 sea cucumbers. The experiment results showed as follows:1) Three treatments of E. prolifera had significant influence on enhancing SGR and reducing FCR of sea cucumbers(P<0.05) and E. prolifera with DCC were best,and three treatments of E. prolifera had no significant influence on FI and SR(P>0.05). 2) The E. prolifera with DCC and DCP had significance on enhancing ADCd and ADCp of diets(P<0.05), and juvenile sea cucumbers had significant higher on ADCd and ADCp of E. prolifera with DCCand DCP than E. prolifera with DC(P<0.05). 3) The E. prolifera with DCC and DCP had significance on enhancing AMS and PP in gut of sea cucumber(P<0.05), andthe AMS of E. prolifera with DCC were highest and the PP of E. prolifera with DCP were highest. Three treatments of E. prolifera had significance on enhancing SOD and ACP in gut of sea cucumber(P<0.05), and the SOD of E. prolifera with DC were highest, the ACP of E. prolifera with DCC were higher than other diets(P<0.05). It can be concluded tha in this condition of the experiment: E. prolifera with dry crushing after cellulase can enhance the growth, digestibility, digestive enzyme and non-specific immunity and decline feed conversion ratio of juvenile sea cucumber It compromises the indexes on growth, digestion and non-specific immunity of juvenile sea cucumber and suggests that E. prolifera with drying crush after cellulase treatment is a ideal way to deal with E. prolifera.