969. TAXONOMIC STUDIES OF THE NEOGONIOLITHON FOSLIEI COMPLEX (CORALLINACEAE, RHODOPHYTA) IN THE RYUKYU ISLANDS

Abstract

Taxonomic studies of the "Neogoniolithon fosliei complex" are conducted on the basis of the Recent materials collected from reefs on Ishigaki-jima (Ishigaki Island), the Ryukyu Islands, southwestern Japan. Detailed morphological and anatomical examination reveals that nonarticulated coralline algae comprising the complex are classified into three species : N. fosliei, N. tenuicrustaceum sp. nov., and Neogoniolithon sp. A. The arrangement of bi-/tetrasporangia in the conceptacle chamber (across the floor or periphery only) or the presence or absence of the central columella is proved to be of potential taxonomic signiflcance for distinguishing Neogoniolithon from Spongites.