The Biology Research About Several Species Of Triplophysa

The genus Triplophysa belongs to the order Cyrpiniformes, the family Cobitidae,subfamily Nemacheilinae, and is one of the largest groups of subfamily Nemacheilinae.Triplophysa fishes were mainly distributed in West Asia, the Tibetan Plateau and theadjacent areas. The purpose of this study was to examine population growth, reproduction,morphological characters and other biological characters of three species of Triplophysa,including Triplophysa stenura, T. brevicauda and T. stewarti, collected from the LhasaRiver. The main results were summarized as follows：1. The population growth and reproductive characteristics of three species of TriplophysaThe average of body length of T. stenura was65.06mm and the average of bodyweight was2.86g. The relationship of body length and body weight was W=1.755×10-6L3.375, and the fullness showed a significant change with seasons. The sex ratio of female tomale among the overwintering population was1.13versus1. The average gonadosomaticindex（GSI）of female was13.95%and that of the male was0.57%. The oocyte diameter ofoverwintering population of T. stenura ranged from0.42to0.86mm, the average was0.66mm. Oocyte diameter distribution showed a single peak. The absolute fecundity and bodylength relative fecundity showed significant correlation coefficient with body length, bodyweight, gonad weight and GSI, but body weight relative fecundity was only significantlyassociated with GSI, not associated with the three other parameters.The average of body length of T. brevicauda was66.87mm and the average of bodyweight was2.94g. The relationship of body length and body weight was W=3.330×10-6L3.224. The sex ratio of female to male among the overwintering population was1.94versus1. The average gonadosomatic index of female was13.52%and that of the male was1.01%. The oocyte diameter of overwintering population of T. brevicauda ranged from0.35to0.85mm, the average was0.60mm. Oocyte diameter distribution showed a singlepeak. The absolute fecundity and body length relative fecundity showed significantcorrelation coefficient with body length, body weight, gonad weight and GSI, but bodyweight relative fecundity was not associated with the four parameters.The average of body length of T. stewarti was71.83mm and the average of body weight was3.10g. The relationship of body length and body weight was W=3.898×10-6L3.624. The sex ratio of female to male among the overwintering population was1.37versus1. The average gonadosomatic index of female was10.95%and that of the male was0.70%. The oocyte diameter of overwintering population of Triplophysa stewarti rangedfrom0.35to0.72mm, the average was0.59mm. Oocyte diameter distribution showed asingle peak. The absolute fecundity and body length relative fecundity showed significantcorrelation coefficient with body length, body weight, gonad weight and GSI, but bodyweight relative fecundity was only significantly associated with GSI, not associated withthe three other parameters.2. Morphological analysis of three species of TriplophysaMultivariate analysis methods were adopted to reseach11conventional measurablecharacters and24truss network of three species of Triplophysa. The ANOVA analysisshowed that T. stenura had significant differences in28traits with T. brevicauda while ithad significant differences in34traits with T. stewarti. And T. brevicauda had significantdifferences in31traits with T. stewarti. The cluster analysis found that T. stenura clusterdwith T. stewarti firstly, and then with T. brevicauda. Six parameters were established thediscriminant function of three species of Triplophysa, and their comprehensiveidentification accuracy rates were to99.03%.