Effects of different macrophytes planting modes on pond culture performance of juvenile Chinese mitten crab Eriocheir sinensis
Alternanthera philoxeroides is the most commonly used aquatic plant in the juvenile crab pond culture process,its community can be formed on the water surface,on which crabs like to perch and feed and the roots of A.philoxeroides are the high-quality bait for crabs.In recent years,due to the frequent insect infestation of A.philoxeroides,the pond culture performance of juvenile crab are greatly affected and it is urgent to find high-quality aquatic plants that can replace A.philoxeroides.Jussiaea stipulacea Ohwi has a similar structure with A.philoxeroides and it has a faster growth rate,strong vitality and better ability to remove ammonia and nitrogen from water.The experiment was conducted to compare the habitat selectivity,growth performance,final cul-ture performance and body weight distribution of crab cultured under three planting modes(single planting of A.philoxeroides,A.philoxeroides and J.stipulacea 1∶1 planting,single planting of J.stipulacea)to explore the effects of different macrophytes planting modes on culture performance of juvenile Chinese mitten crab Eriocheir sinensis.The results showed that the growth rate of J.stipulacea was significantly faster than that of A.philoxeroides.The average body weight of resident crabs in J.stipulacea were significantly higher than that of A.philoxeroides.However,the number of resident crabs in J.stipulacea were significantly lower.In the whole cul-ture stage,the growth rate of crab in J stipulacea groupwas the fastest,followed by that in 1∶1 planting treat-ment,and the growth rate of crab in A.philoxeroides group was the slowest.Juvenile crabs in A.philoxeroides group were characterized by high survival rate,low precocious puberty rate and low disability rate,but the 1:1 planting group had the highest yield.In terms of body weight distribution,the body weight of crabs in each group was mainly concentrated in 6.00-8.99 g and 9.00-11.99 g intervals,and the proportion of crabs in 9.00-11.99 g,12.00-14.99 g and ≥ 15 g intervals was higher in J.stipulacea group.In conclusion,in the ju-venile stage of the Chinese mitten crab,the use of J.stipulacea could improve the average body weight of the crab than A.philoxeroides.Still,its yield and survival rate would be reduced,and the combination of the two could achieve higher yield.In this study,the 1:1 planting group achieved a higher yield,which may be due to the fact that A.philoxeroides and J.stipulacea formed a complementary situation.This finding provides a new di-rection for the selection of aquatic plants in the future crab pond culture stage,and the combined use of aquatic plants may be the future trend of crab pond culture.
万方数据
