A New Species of <i>Semicytherura</i> (Crustacea: Ostracoda: Cytheroidea) from Obitsu River Estuary (Central Japan) and Its Microhabitat

Abstract

A new ostracod species, Semicytherura obitsuensis sp. nov., is described from the intertidal zone of the Obitsu River estuary, Chiba Prefecture, central Japan. As S. obitsuensis sp. nov. individuals were collected from muddy sand bottoms in tidal creeks, possess some carapace-features comparable to those of interstitial and infaunal ostracods, and were observed to crawl in detritus rich fine-grained sediment in the laboratory, we concluded that this new species is an infaunal species.

Revision of the Semicytherura henryhowei group (Crustacea, Ostracoda) with the new records from Korea

“…It comprises at least 291 species, 126 of which are known only from the fossil record. A total of 283 of these species are listed in the World Register of Marine Species (Brandão et al 2022), whereas at least the following eight are missing: Semicytherura leptosubundata (Ozawa & Kamiya, 2008), S. obitsuensis (Nakao & Tsukagoshi, 2020), S. pseudoundata Irizuki & Yamada in Irizuki et al (2004), S. robustundata (Ozawa & Kamiya, 2008), S. skippa (Hanai, 1957), S. subslipperi Ozawa & Kamiya, 2008, S. tanimurai (Ozawa & Kamiya, 2008), and S. tetragona (Hanai, 1957). The last species was described as Cytherura tetragona Hanai, 1957 and is still listed as such in the World Register of Marine Species (Brandão et al 2022).…”