Comparative Osteology of the Sciaenid Fishes from Japan and Its Adjacent Waters-I.Neurocranium

Abstract

Based on the characters of the neurocranium, 16 species of the sciaenid fishes are classified into Megalonibea-, Nibea-, Johnius-, Argyrosomus- and Pseudosciaena-forms.The Megalonibea-form comprises the genera Megalonibea, Miichthys and some species of Nibea;the Nibea-form the remain-ing species in the genus Nibea;the Johnius-form the genera Johnius and Wak;the Argyrosomus-form the genera Argyrosomus and Atrobucca;the Pseudosciaena-form the genera Pseudosciaena and Collichthys.Of these five forms, the Megalonibea- and Nibea-form are probably the most gene- ralized, and the Pseudosciaena- and Johnius-form specialized.The Argyrosomus-form is considered to be intermediate between the Nibea-form and Pseudosciaena-form.The neurocranium is proved to be an important character as well as the sagitta for the speculation of phylogeny of the sciaenid fishes.