Reexamination of Ege's (1939) use of taxonomic characters of the genus Anguilla

Abstract

An extensive reexamination of the morphological characters used for the taxonomy of the genus Anguilla was made, and new morphological characters were developed to solve several of the taxonomic problems of the genus. A total of 14 morphological characters that included 12 of the taxonomic characters used by Ege and two new characters were studied in a total of 1713 specimens that consisted of 1497 collected specimens and 216 museum specimens. Color marking clearly separated two groups in the genus Anguilla, but the ranges of the other 13 characters partially or completely overlapped among all species and subspecies. The present study found that the combination of color markings, width of maxillary bands, and origin of the dorsal fin divided the genus Anguilla into four groups, but the similar morphology of all species indicated that it would be necessary to revise the taxonomy of the freshwater eels with new characters and methods.