ABSTRACT
Watersipora is one of the common bryozoan genera in Japanese shallow waters, but reports with detailed taxonomic descriptions of this group are limited. Recently, Japanese Watersipora has been classified into several species based on the morphology of their pseudopores and operculum. However, the distribution of each species and the microscopic differences in their morphology along the Japanese coast is still unknown. In this study, we reexamine the morphological characters of Japanese Watersipora collected from several different localities on the Japanese coast based on detailed observations of pseudopores and molecular phylogenetic analyses using the cytochrome c oxidase subunit 1 mitochondrial gene (COI), we identify the species and to verify the diagnosis of the species so that they reflect genetic differences within the genus. In the preliminary results, the number of pseudopores varies within the same genetic group. In contrast, the characters of their operculum better reflect the genetic distances between taxa.
