MORPHOLOGICAL VARIATIONS AND SPECIES VALIDITY OF GENUS EUCHILOGLANIS (SILURIFORMES:SISORIDAE)IN CHINA

The delimitation between Euchiloglanis davidi and Euchiloglanis kishinouyei has not been clear all the time. In the present paper, we studied inter specific and intra specific variations of E.davidi and E.kishinouyei by principal component analysis and 548bp mtDNA 16S rRNA sequences analysis. 35 characters were measured and 34 among them were analyzed using multivariate morphometrics for 80 specimens of the genus Euchiloglanis.We amplified and sequenced the mtDNA 16S rRNA gene fragments in 10 individuals of Euchiloglanis. Sequences were read from one strand (L strand) and aligned using Clusta1X 1.8 program and SEAVIEW program. Pairwise sequence comparisons to determine the amount of variation were performed using MEGA 2.1. According to the results of principal component analysis and p distance,the species validties were evaluated. The results showed that: (1)the diagnostic characters between E. davidi and E.kishinouyei,such as anterior position of ventral fins, its origin being always nearer or not to lower angle of gill opening than to anal fin,maxillary barbells extending beyond or not to gill opening,were correlated. However, specimens could not be distinguished definitely according to these differences because of the overlap in characters;(2)there were differences among populations from different localities,but no definite correlation to the tributary of Jinshajiang River could be found;(3)the genetic distance was very small between E.davidi. and E.kishinouye,and it was only 0.075% on average;(4)Only 2 variation loci were detected and the mutation rate was 0.365%;(5)the genetic distance was also small among the genus Euchiloglanis, ranging from 0—0.381% and 0.069% on average.Based on these results, Euchiloglanis species in China is suggested as only one species,and E.kishinouyei is argued as a synonym of E.davidi.