Molecular identification of species of subfamily Corydoradinae (Siluriformes: Callichthyidae)

Abstract

The Neotropical freshwater fish fauna is the richest in the world. Of the estimated 13,000 species of freshwater fish, about 6,000 species are found in the Neotropical region and it is estimated that this number will reach over 8,000.The family Callichthyidae, composed of the subfamilies Corydoradinae and Callichthyinae, is a very specious group, with a total of 199 valid species, and includes, among others, the genus Corydoras, the largest among the Siluriformes. Callichthyidae have a wide geographical distribution, occurring from rivers of the Pacific slope, in Panama, to the basin of the La Plata River in eastern Argentina. Some authors have proposed the use of a segment of approximately 650 base pairs of 5' end of the mitochondrial gene cytochrome c oxidase subunit I (COI) as a universal identification system suitable for most animal species. The recommendations suggest that five copies should be sampled from each species, coming whenever possible, from different points within the study area.Considering the promising use of DNA barcode to species identification, the present study aimed to test the hypothesis that it is possible to molecularly identify the species of Corydoradinae, using the technique of DNA barcoding and with the data generated to create a database to allow molecular identification of the specimens studied. (AU)