A Revision of the Osmerid Genus Hypomesus Gill (Teleostei : Salmoniformes), with the Description of a New Species from the Southern Kuril Islands

Abstract

A systematic revision of the osmerid genus Hypomesus Gill, based on a detailed analysis of external and internal morphological characters, revealed the presence of six species, one of which is described as new. These six species fall readily into three species-groups : the Hypomesus nipponensis group, containing H. nipponensis McAllister, H. chishimaensis new species, and H. transpacificus McAllister ; the H. olidus group, containing only H. olidus Pallas ; and the H. japonicus group, containing H. japonicus Brevoort and H. pretiosus Girard. Synonymies, diagnoses, and descriptions are given for all taxa, geographic distributions are described and plotted, and a key to the species of the genus is provided.