Abstract

Guentherus altivela, long known from the west coast of Africa, is described from 14 specimens collected off the Pacific coast of Costa Rica and Panamá. The eastern Pacific form is remarkably smiilar to literature descriptions and comparative material of the eastern Atlantic form. The Pacific population has a smaller mean number of anal rays (74.0 vs. 78.1), and a slightly longer head, upper jaw and first free pelvic rays.

The present discovery fills a major gap in the cosmopolitan distribution of the Ateleopodidae. It is suggested that G. altivela is a trans-Atlantic species which populated the eastern Pacific before the last emergence of the Central American land bridge; its eventual discovery in the western Atlantic could be expected.