The Sympatric Occurrence of the Carapid Fishes Pyramodon ventralis and P. lindas in Japanese Waters

Abstract

Twenty-five specimens of Pyramodon ventralis from Japanese waters and seven specimens of P. lindas recorded for the first time from Japanese waters were examined and compared with the holotypes of both species. The two species are distinguished by differences in coloration of the dorsal and anal fins, number of dorsal-fin rays to the anal-fin origin as previously indicated. We present two additional characters differentiating the species: morphology of the dorsal surface of the cranium, and relative length from the pelvic-fin base to the middle of the vent. Counts of pectoral-fin rays and precaudal vertebrae in both species exhibit wider intraspecific variation than previously reported. Some morphometric characters are discussed in relation to head length.