Comparative Study On Culture Performance And Nutritional Quality Of Eriocheir Sinensis From The Yangtze River Population And The Yellow River Population In The Yellow River Estuary

The Chinese mitten crab,Eriocheir sinensis,occupies an important position in Chinese aquaculture industry and is a main freshwater crab in China.Because of the early reproductive period of Chinese mitten crabs in North China,it can be put on the market in advance,which forms a cross-peak with the Chinese mitten crab of southern.This is conducive to promoting the development of the Chinese mitten crab breeding industry in northern,which can not only give play to local advantages,but also improve the economy of Chinese mitten crab industry.There are several studies on the growth performance and nutritional quality of Eriocheir sinensis from different population in the Yangtze River basin,but there are no studies on the growth indicators of Eriocheir sinensis in the Yellow River basin.In view of this,this study systematically studied the breeding performance and nutritional quality of Chinese mitten crab at the juvenile crab and adult crab stages in the Yangtze River and Yellow River population under pond culture conditions,in order to provide basic data and scientific basis for crab species screening in the Yellow River estuary area.1.Growth performance of larva of Chinese mitten crab（Eriocheir sinensis）in the Yangtze River and Yellow River populations in the Yellow River estuaryThe purpose of this study was to investigate the difference of growth rate and culture effect of Chinese mitten crab（Eriocheir sinensis）at the clasp crab stage in the Yangtze River and the Yellow River populations.Six ponds with the same area were selected in the breeding base of Dongying,and metazea by Chinese mitten crabs from two rivers were cultivated into clasp crabs.In this study,we systematically compared the changes of average body weight,weight gain rate and specific growth rate of Chinese mitten crabs from Yangtze River and Yellow River basins during juvebile culture stage,and further compared the differences in the distribution of final formation size.The results showed that:（1）The average body weight of the Yellow River population was always lower than that of the Yangtze River population at the juvenile culture stage.The average body weight of the Yellow River population was significantly lower than that of the Yangtze River population in July（P<0.05）,and that of the Yangtze River population in August（P<0.01）.In addition,in August of the Yellow River population clasp crab average weight is significantly lower than the Yangtze River population（P<0.01）.（2）The two populations exhibited a similar alteration in the weight gain rate（WGR）and specific growth rate（SGR）of Chinese mitten crabs during the juvenile stage.The WGR and SGR of males in the Yangtze River population were significantly higher than those in the Yellow River population from July to August（P<0.05）,and were notably lower than those in the Yellow River population from August to September（P<0.01）,but the WGR and SGR of female crabs in the Yellow River population were significantly higher than those in the Yangtze River population from August to September（P<0.01）.（3）In terms of the final size distribution,the final size distribution of the Yangtze and Yellow Rivers was concentrated in the range of 0～8.99g,accounting for 86.66%and 87.91%of the whole population,respectively.2.Comparison of growth performance of Chinese mitten crab（Eriocheir sinensis）from Yangtze River with that from Yellow River during the adult culture stage in the Yellow River estuary areaTo investigate the growth performance of Chinese mitten crab（Eriocheir sinensis）from Yangtze River and Yellow River in the Yellow River basin.In this experiment,the juvenile crab from Yangtze River and Yellow River basins was selected as the experimental from March to November 2021 in the Yellow River estuary area of Dongying.In order to provide a scientific basis for the selection of crab species in the Yellow River estuary,we compared the growth performance and gonadal development of Chinese mitten crabs in the adult stage between the Yangtze River basin and the Yellow River basin through sampling after each shell exchange,anatomical analysis and statistics of the final culture results.The results showed that:（1）Under similar/same culture environment,there was no significant difference in the average body weight of crabs from different basins.However,the average body weight of female body of Yangtze River population was significantly higher than that of Yellow River population at the later stage（July to September）.The changes of specific growth rate（SGR）and weight growth rate（WGR）of Eriocheir sinensis from two basins were similar,and the SGR and WGR of female crabs from Yangtze River were significantly higher than that of Yellow River crab from May to July.（2）In terms of reproductive molting,the Yellow River crab molted10～15 days earlier than the Yangtze River crab,but the peak of female and male adult crab molting was similar,starting at the end of August and early September,respectively.（3）The final average boby weight of Yangtze River population was significantly higher than that of Yellow River population,but the survival rate of Yellow River crab was higher than that of Yangtze River crab,so the final adult yield of Yangtze River crab and Yellow River crab were basically the same.On the whole,under similar or the same breeding environment in Dongying,the gonad development time of Yellow River crab was earlier,and the final size of Yangtze River crab was larger.This indicates that the size of Yangtze River crab cultivated in the Yellow River estuary has certain advantages in growth,and its low survival rate can be improved by localization culture.This provides a possible way for breeding of Chinese mitten crab in the Yellow River estuary.3.Comparison of nutritional quality of adult Eriocheir sinensis from the Yangtze River and Yellow River populations cultured in ponds at the Yellow River estuary areaIn this study,Chinese mitten crabs from the Yangtze River and the Yellow River were cultured in ponds in the Yellow River estuary,and the edible tissue proportion,edible yield and nutrient composition of the two populations were compared.The results showed as follows:（1）The gonadal index（GSI）and condition factor（CF）of Yellow River crab were slightly higher than those of Yangtze River crab,and the other indexes were lower than those of Yangtze River crab,but there was no significant difference（P>0.05）.（2）There were no significant differences in the content of moisture,protein and lipid in edible tissues between the two populations（P>0.05）,but the ash content in female hepatopancreas and male gonad of Yangtze River Yangtze River population was significantly higher than that of Yellow River Yangtze River population（P<0.05）,which may be related to culture environment and genetic characteristics of different populations.（3）In terms of fatty acid composition in edible tissues,the contents of C_18:1n9 and total mono-unsaturated fatty acids（∑MUFA）in female hepatopancreas of Yangtze River population were significantly higher than those of Yellow River population（P<0.05）,while the contents of total n3 poly-unsaturated fatty acids（∑n-3PUFA）were significantly lower than those of Yellow River population（P<0.05）.The females of the Yangtze River population gonads had a significantly greater DHA content than those of the Yangtze River population（P<0.01）.In muscle,the DHA content in females of the Yellow River population was significantly higher than that of the Yangtze River population（P<0.05）,the content of total highly unsaturated fatty acid（∑HUFA）was significantly higher than that of the Yangtze River population（P<0.01）,andΣHUFA content in males was significantly higher than that of the Yangtze River population（P<0.05）.（4）The females of the Yangtze River population exhibited significantly greater proline,threonine,glutamic,acid serine,and methionine in their muscles than the Yellow River population（P<0.05）.In males,the Yangtze River population except the lysine,methionine,arginine and histidine,the rest of the amino acid content were significantly higher than the Yellow River population（P<0.05）.The average EAAS of the muscles of the Yangtze River population was higher than that of the Yellow River population.In conclusion,the GSI of Chinese mitten crabs in the Yellow River population is relatively high due to its early reproductive molting,and the nutritional value of gonadal fatty acids was higher than that of the Yangtze River population,but the nutritional value of amino acids in muscle was lower than that of the Yangtze River population,which may be related to genetic factors.