Effect Of Spermine And Mannan Oligosaccharide On Growth, Digestive System Development Of Tongue Sole(Cynoglossus Semilaevis Günther) Postlarvae

Feeding trials were conducted to investigate the Influence on growth, digestivesystem development of spermine and mannan oligosaccharide for tongue sole(Cynoglossus semilaevis Günther) postlarvae. Results of the study are presented asfollows:1. Cynoglossus semilaevis postlarvae, with initial length of2.09±0.05cm, werefed with microdiet containing0%(F1),0.10%(F2),0.33%(F3) of spermine and a liveArtemia group (F4) for28days feeding to study the effect of the intestinal development.The results showed that F4group exhibited the highest growth and survival. Thespecific growth rate of F2group was significantly higher than that of F1and F3group(P<0.05). The survival rate in F3group was60.27%, significantly lower than that ofother groups (P<0.05). At14days, the alkaline phasphatase relative activities (AP) inbody of fish fed microdiet with spermine inclusion was significantly higher than that offish fed the Artemia group (P<0.05), and no significant difference was found amongdiets with spermine inclusion (P>0.05); at28days, the AP in body of fish fed microdietwith0.10%spermine inclusion was significantly higher than other groups (P<0.05), andno significant difference was found in other groups (P>0.05). F2and F3group hadhigher leucine aminopeptidase (LAP) specific activity than F1and F4group at14and28days (P<0.05), and no significant difference was found among of them (P>0.05). F2group had lowest leucine-alanine peptidase (leu-ala) specific activity at14and28days(P<0.05). The microvilli length of Artemia group was significantly greater than that ofthe other groups (P<0.05), the mucosal thickness of Artemia group was less than that ofF2group, but there was no significant difference (P>0.05); the length of microvilli andthe mucosal thickness in F2were greater than that of F1and F3group (P<0.05). This result suggested that0.10%spermine in microdiet had a positive effect on intestinaldevelopment of tongue sole postlarvae.2. Cynoglossus semilaevis Günther postlarvae, with initial length2.09±0.05cm,were fed with microdiet containing0%(F1),0.10%(F2),0.33%(F3) of spermine and alive Artemia group (F4) for28days feeding to study the effect of the development ofthe pancreatic exocrine function. At14days, amylase relative activity was significantlylower in fish fed dietary spermine than fish fed with control diet (P<0.05), whereasCholecystokinin and trypsin activity showed no significant differences among the threemicrodiet treatments (P>0.05). At28days, Cholecystokinin and pancreatic enzymesactivities all increased in fish fed dietary spermine than fish fed with controldiet(P<0.05). Amylase mRNA expression was significantly higher in fish fed dietaryspermine than fish fed with control diet (P<0.05). There was no significant difference inexpression of pretrypsinogen gene among the three microdiet treatments (P>0.05). Inconclusion, high spermine level (0.33%) had toxic and appropriate spermine level(0.10%) could improve the pancreatic exocrine function.3. Cynoglossus semilaevis Günther postlarvae, with initial length1.4±0.07cm,were fed with Artemia enhancement Mannan oligosaccharide (MOS) to study the effectof the growth、 intestinal development and non-specific immunity. Two groups (controlgroup and MOS group) were set, feeding Artemia enriched by the Schizochytrium andmannan oligosaccharides plus Schizochytrium respectively. The experiment lasted34days, and was sampled every17days. The results showed that the body length of fish inMOS group was lower than that in control group (P<0.05) at17days. Between the twogroups in the specific growth rate and survival rate was not significantly different(P>0.05). The ratios of RNA/DNA and protein/DNA between the two groups were notsignificant (P>0.05) at17days, but, that of the MOS group was higher than those in thecontrol group at34days (P<0.05). The amylase specific activity at17days and trypsinspecific activity at34days in fish of MOS group were higher than that of controlgroup(P<0.05). The superoxide dismutase, catalase, peroxidase and lysozyme activity infish of MOS group were significantly higher than that of control group (P<0.05). Themicrovilli length and the fold highness of MOS group was significantly greater than thatof the control group (P<0.05); the mucosal thickness between the two groups were not significant (P>0.05). The results indicated that MOS could improve the intestinaldevelopment and non-specific immunity in Cynoglossus semilaevis Günther postlarvae.