Preliminary Study On The Develpoment Biological Characters Of Leptobotia Taeniops In Tongling Section Of The Yangtze River

Leptobotia taeniops, endemic to China, belongs to Leptobotia, mainly distributes in the middle and lower reaches of the Yangtze River and its affiliated waters, From June2008to June2010,279specimens were collected from Tongling section of the Yangtze River to study morphological characteristics, age structure, growth parameters, reproduction traits.Leptobotia taeniops body colour is purple or yellowish-brown. Scales can be used for aging, vertebra is corroborative evidence. Analysis of the catch showed that it mainly consisted of six age groups from one to six. Both age2and3groups were dominant, respectively occupying26.88%and43.30%. The number of individuals of age6was least. The average length was9.20±1.03cm (ranged from6.81to12.40cm), mainly8.00～10.00cm (70.25%) and the average weight was15.30±5.57g (ranged from5.40to36.24g), mainly10.00～18.00g (62.72%).The relationship between body length and the diameter of the scale was L=52.67R+5.5607(R2=0.4456, n=279).Length-weight relationship was W=0.028L2.8212,R2=0.8097. Growth took on a constant speed style,which could be described by the Von Bertalanffy equations. The growth equations were Lt=14.3768(1-e-0.2750(t+0.1550)) Wt=51.6600(1-e-0.2750(t+0.1550))2.8212. The body weight growth inflexion point was3.62years.The number of reproductive population of Leptobotia taeniops was161and the ratio of female to male was1:1.4. All females and males of age2reached maturity.The minimum mature of female was7.40cm in length and7.00g in weight.The minmum mature of male was7.20cm in length and8.00g in weight. The breeding season of Leptobotia taeniops was from April to July, and the epacme was from May to June, and the gonadosomatic index exhibited peak during this time.The mean maturity egg’s radius was1.47±0.10mm. Leptobotia taeniops is nonrecurring spawning fish and its eggs were half-floating.The individual absolute fecundity(F) of Leptobotia taeniops ranged from372to7005eggs with an average of2277.8±1310.5. The relative fecundity per centimeter(F/L)ranged from44.3to673.6eggs with an average of233.4±122.4eggs. The relative fecundity per gram(F/W0) ranged from41.3to350.3eggs with an average of151.1±70.3eggs. F, F/L and F/Wo totally increased with age. There were highly significant correlation between F, F/L and L, W, Wo, Wx, GSI (P<0.01). The highly significant correlation was found between F/Wo and GSI (P<0.01).The gonad development of Leptobotia taeniops can be divided into6stages. The histological structure of the ovary and testis respectively came back to stage Ⅲ and Ⅱ after reproduction. And the ovary matured only once in a year.This study accumulates biological data and scientific basis for artificial propagation and domestication of Leptobotia taeniops.