Study on the population composition and growth characteristics of Corbicula fluminea in the Tai Lake
In order to understand population size composition,age structure and growth characteristics of Corbicula fluminea in Tai Lake,638 individuals of C.fluminea collected from six sampling sites in Tai Lake were analyzed.The shell length,shell width,shell heigth and wet weight of C.fluminea were measured and the ages of all individuals were determined.Furthermore,the growth equations of shell length and wet weight of C.fluminea were established.The research results are as follows.(1)The shell length,shell width,shell height and wet weight of C.fluminea ranged from 5.45 to 40.34 mm,from 6.68 to 24.89 mm,from 7.15 to 37.41 mm and from 0.15 to 19.27 g,respectively,the corresponding average values were(20.17±0.60)mm,(13.57±0.33)mm,(19.13±0.53)mm and(4.09±0.32)g,respectively.(2)The C.fluminea population consisted of five age groups(0+-4+),in which the number of individuals aging from 0+ to 2+ yr accounted for 91.85%,and the number of individuals aging from 3+ to 4+ yr accounted for 8.15%.(3)The relationship between shell length and wet weight was expressed as W = 2.0×10-3L2.477(R2=0.954)which indicated that C.fluminea grew at an allometric rate.(4)The relationships between shell length and age were described by Von Bertalanffy equations:Lt = 41.99×[1-e-0.27(t+1.47)],and the relationships between wet weight and age were described by Von Bertalanffy equations:Wt = 19.28×[1-e-0.27(t+1.47)]2.477.The growth inflection point of C.fluminea occurred at age 2.22 yr,with the corresponding shell length of 26.48 mm and wet weight of 6.16 g.The present results suggested that small size and low age individuals dominated the C.fluminea population and the intensity of resource utilization was too high.Therefore,it is urgent to take measures to protect the natural resources of C.fluminea in Tai Lake.
Corbicula flumineapopulation compositionage structuregrowth equationTai Lake