Akoyazara, a new genus of limpet-shaped trochids, with redescription of Broderipia J.E. Gray, 1847 (Vetigastropoda: Trochidae: Fossarininae)

Abstract

ABSTRACT The generic assignment of ‘Broderipia’ eximia has been problematic in the past, and here we propose a new trochid genus Akoyazara n. gen. for it and compare this with Broderipia. The type species of both genera have limpet-shaped shells, but they differ from each other in shell height, external shell sculpture, shell colour pattern, length of epipodial tentacles, shape of the cutting edge of the radular teeth, the presence or absence of a sensory organ at the base of each epipodial tentacle and a genitalia-like projection on the right side of the head. The strong radial ribs on the external shell surface of Akoyazara eximia are suggested to be an adaptation to highly exposed shores. The depressed limpet-shaped shell of Broderipia iridescens is likely to be adaptive, allowing access to narrow spaces in pits carved from rock, which have been bored and occupied by the sea urchins with which they live. Broderipia nitidissima is also transferred to Akoyazara (n. comb.), and this new genus currently includes only two species. New lectotypes of the type species of Broderipia, B. rosea and B. iridescens are designated herein based on specimens in the collection of the Natural History Museum, London.