Abstract

The freshwater fish of the genus Cheirodon are represented in Chile by five species: Cheirodon pisciculus, Ch. australe, Ch. galusdae, Ch. kiliani and Ch. interruptus, the last introduced accidentally from Argentina. The scarce morphological differentiation as well as the sympatric association of Ch. pisciculus with Ch. interruptus and Ch. galusdae with Ch. australe in part of their distributions makes identification difficult, thus it is useful to know the morphological differences and similarities of these four species. By examining 14 morphological measures using Discriminant Analysis (LDA) and Principal Components (PCA), we found a significant separation between the species, especially in characters associated with the insertion of the pectoral and pelvic fins and measures of body height and caudal peduncle. We also analyzed 17 landmarks with geometric morphometrics using PC and UPGMA grouping. The results showed a separation between the four species, obtaining morphologic relations that distinguish each other. The UPGMA grouping coincided partially with the results of Campos (1982) and Malabarba (1994), although Ch. kiliani should be included, of which there are no recent records of capture. The results show that the four species analyzed have clear morphological differences applicable to their rapid recognition. The characters analyzed produced a morphological distinction that allows their recognition in the field in a clear and simple manner.