Original paper

Comparative morphology of glochidial shells of Inversiunio (Bivalvia: Unionidae) from Japan

Sayenko, Elena M.; Akiyama, Yoshihiro B.

Abstract

Glochidial characters may help to clarify evolutionary relationships among unionid taxa with unclear taxonomic positions. Mature glochidia of three species of Inversiunio Habe, 1991 that occur in Japan—I. reinianus Kobelt, 1879, I. jokohamensis (von Ihering, 1893), and I. yanagawensis Kondo, 1982—were examined with the aim of assessing the taxonomic utility of the morphological and morphometric characters of their glochidial shells. All morphological indices of glochidia showed no statistically significant differences and were regarded as not useful for identification among investigated Inversiunio species. Four different types of external glochidial valve fine sculpture were revealed that support proposed phylogenetic relationships based on genetic data.

Keywords

Bivalviafreshwater molluskglochidia