Studies On Age,Growth And Reproductive Biology Of Gymnocypris Potanini Firmispinatus Wu Et Wu In The Anning River

A total of 582 Gymnocypris potanini firmispinatus Wu et Wu,1988 individuals were captured from the Anning River during July 2015 and June 2016,to study the age,growth and reproductive characteristics of the fish.The objectives of this study were to obtain basic biological information and provide information for population resources conservation.The main results are as follows:1.Otoliths,vertebrae and opercular bones of G.p.firmispinatus showed the typical annulus pattern,which was characterized by alternative wide zones and narrow zones.Annuli of otoliths formed from March to May once a year.Annuli on the otoliths were clearer than other two age materials.Otoliths were the best age material,followed by vertebrae and opercular bones.2.The standard lengths(SL)of G.p.firmispinatus ranged 47~207mm for females,45~137mm for males and 23~69mm for the undetermined.The weights(W)ranged 1.7~148.17 g for females,1.48~41.58 g for males,0.16~4.88 g for the undetermined.The ages ranged 1~13 years for females,1~9 years for males,and only 1~2 years for the undetermined.The length-weight relationships were described as W=2.01×10-5SL2.955(R2=0.9738,n=582).The von Bertalanffy growth equations were Lt=258.0[1-e-0.105(t+1.058)] and Wt=268.9[1-e-0.105(t+1.058)]2.955 for females,and Lt=188.0[1-e-0.102(t+3.494)] and Wt=105.5[1-e-0.102(t+3.494)]2.955 for males.The growth performance index of females and males were 3.84 and 3.56,respectively.The inflexion points for the growth of females and males were 9.26 and 7.13 years,respectively.3.The female and male ratio was 0.97:1,which did not differ significantly from 1:1.The estimated first maturity sizes were 119.24 mm for females and 69.81 mm formales.The estimated first maturity ages were 6.79 years for females and 2.51 years for males.Based on macroscopic stage of gonads,gonadosomatic index(GSI)and the size distribution of oocytes over month,G.p.firmispinatus was single spawner with a short-term spawning pattern during March and April.The absolute fecundity of G.p.firmispinatuswas from 550 to 3 257 eggs per fish,with an average of 1 284±556 eggs per fish.The relative fecundity was from 16 to 62 eggs/g,with an average of 37±14 eggs/g.The relationships between the absolute fecundity and standard length/weight were power correlated,the relationship between fecundity and ovary weight was bivariate polynomial correlated,while fecundity was not significantly correlated with age.