| In this paper, the stock population and the wild population Chinese mitten crab(Eriocheir sinensis) in Yangtze River estuary were studied. The blood biochemicalindexes and the energy in the gonad and hepatopancreas of the wild population andstock population mature crab at different ovarian development stages were analyzed.Also, the fecundity of different ranges between the stock and wild population maturecrab was compared. The purpose of the paper was to study the adaptability to theenvironment when the stock population crab was released. In addition to that, it was animportant theoretical basic for the stock enhancement.1. The comparison of blood biochemical indicators of female crabs between wildand stock Chinese mitten crab in Yangtze River estuaryDuring the reproductive migration of Chinese mitten crab in the Yangtze Riverestuary,9blood biochemical indexes of the wild population crab and stock populationcrab at different ovarian development stages were analyzed. The results showed thatthere wsa no significant difference on serum total protein (TP), hemocyanin,triglyceride (TG), creatinine (CREA), Ca2+and Mg2+(P>0.05) between wild and stockpopulation crab at different ovarian development stages. At stage Ⅳ and Ⅴ, theserum-albumin (ALB) values of stock population crab were significantly higher thanthat of wild population crab(P<0.05). The serum carbamide (UREA) values of stockpopulation crab were significantly higher than that of wild population crab (P<0.05) atstage Ⅳ. The serum total cholesterol (TC) values of stock population crab weresignificantly higher than that of wild population crab at later stage Ⅵ (P<0.05). Itcould be concluded that there were no significant differences in serum biochemicalindexes except some individual ones. The stock population crab could adapt theenvironment well, and accomplish the ovarian development successfully. Therestocking of Chinese mitten crab is of positive significance to the increase of crab yield in Yangtze River estuary.2. The comparison of fecundity of female crabs between stock and wild Chinesemitten crab in Yangtze River estuaryDuring the reproductive migration of Chinese mitten crab in the Yangtze Riverestuary, the relationship between fecundity and carapace width of stock and wildChinese mitten crab populations was analyzed, and then the differences between thewild and stock populations were compared. The results showed that, with the increaseof carapace width, the fecundity of stock and wild population crabs was increasedsignificantly（P<0.05）. The fecundity in the same range of carapace width, there was nosignificant differences between the wild and stock population crab (P>0.05). Regressionanalysis showed that the relationship between fecundity (F) and carapace width (CW) ofthe stock population crab belongs to Exponedtial function: the function isF=3.979CW6.208（R2=0.822）Also, regression analysis showed that the relationshipbetween fecundity (F) and carapace width (CW) of the wild population crab belongs toExponedtial function: the function is F=1.696CW6.636(R2=0.673)..Covariance analysisshowed that the curves of the wild and stock population crab fit well in significant0.05.It could be concluded that, there was no significant differences between the wild andstock population crab on the F and CW. The stock population was able to adapt to theenvironment of the natural waters in the Yangtze River estuary. The fecundity of thewild and stock population was in the same level.3. The comparison of gonad and hepatopancreas between the stock and wildpopulation Chinese mitten crabDuring the reproductive migration of Chinese mitten crab in the Yangtze Riverestuary, the gonad and hepatopancreas were compared between the stock and wildpopulation Chinese mitten crab in different gonad development stage. The resultsshowed that in different gonad development stage, the hepatopancreas indexes weredecreased significantly (P<0.05), regardless of the stock and wild population. Thehepatopancreas indexes did not get any differences between the stock and wildpopulation (P>0.05). To stock population crab, the total lipids of gonad drawn downsharply in the stage VI1(P<0.05). So was the wild population. And the total lipidincreased significantly in the stage VI2of the wild population (P<0.05). To the stockpopulation, the total protein of the gonad went up remarkable in the stage V (P<0.05).And the total protein fell in the next stage. To the wild population, the total protein of the gonad had the same tendency with the stock population in the former three stages,but the total protein decreased significantly in the stage VI2(P<0.05). In the differentgonad development stages of the stock and wild population, the total lipids in thehepatopancreas decreased gradually. To the stock and wild population, the total proteinof the hepatopancreas changed smoothly in the different gonad development stage(P>0.05). In the same gonad development stage of the stock and wild population, therewere not any significant difference in the GSI and HSI、the total lipids of the gonad(P>0.05). The total protein of the gonad and hepatopancreas, the stock population wassmaller than the wild population (P<0.05). To the total lipids, there were not anysignificant differences between the stock and wild populations. But, the total lipids ofthe stock population were less than the wild population. Those differences show that thestock population did not get the same energy substance level with the wild population.To add the stock enhancement effect, the nutrition of the stock population should bestrengthened before the crabs were cast to the river. |
PDF Full Text Request