Ostracod Research at the Lake Biwa Museum, Japan

Robin James Smith

Genus Cypris O. F. Müller, 1776

Superfamily: Cypridoidea Baird, 1845
Family: Cyprididae Baird, 1845
Subfamily: Cypridinae Baird, 1845

Two species have been reported from Japan:

1. Cypris granulata Daday, 1898

Dorsal view of a female Cypris granulata, length just over 1 mm. Anterior to the right.

External view of a female left valve of Cypris granulata, length 1296 microns. The valves are strongly pitted.

External view of a female right valve of Cypris granulata, length 1301 microns.

Additional figures in: Okubo 1972 (as Cypris subglobosa); Okubo & Ida, 1989 (as Cypris subglobosa); Smith et al. 2011 (as Cypris sp.).
Habitat: Littoral zone of Lake Biwa (Smith et al. 2011; as Cypris sp.). Other Japanese records from rice fields (Okubo 1972; as Cypris subglobosa), ponds, pools, and a pool in a cave (Broodbakker 1988; as Cypris subglobosa).
Mode of life: Nektobenthic (swimmer).
Reproduction mode: Asexual, males unknown.
Known distribution: Shiga Prefecture (Smith et al., 2011; as Cypris sp.), Okayama Prefecture (Okubo 1972; as Cypris subglobosa), Gumma Prefecture (Okubo & Ida 1989; as Cypris subglobosa), Kagoshima Prefecture and Okinawa (Broodbakker 1988; as Cypris subglobosa). Outside of Japan this species has a global circumtropical distribution (Martens 1990; as Cypris subglobosa).
Notes: This extant species has frequently been called "Cypris subglobosa Sowerby, 1840", but research has revealed that the syntypes of this species, fossils from India, are a different species and genus to living specimens (Whatley et al. 2003). The living species should be called Cypris granulata Daday, 1898 (Meisch et al. 2019).
References:
⚬ Broodbakker, N. W. 1988. Ecology and distribution of groundwater Crustacea and freshwater Ostracoda in SW Honshu and the Nansei Islands, Japan. Verlagen en Technische Gegevens Institute voor Taxonomische Zoologie, 53, 1-21.
⚬ Martens, K. 1990. Taxonomic revision of African Cypridini. Part I: the genera Cypris O.F. Müller, Pseudocypris Daday and Globocypris Klie (Crustacea, Ostracoda). Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Biologie, 60, 127-172.
⚬ Meisch, C., Smith, R. J. & Martens, K. 2019. A subjective global checklist of the extant non-marine Ostracoda (Crustacea). European Journal of Taxonomy, 492, 1-135.
⚬ Okubo, I. 1972. Freshwater Ostracoda from Japan, II. Cypris subglobosa Sowerby, 1840. Review of Shujitsu Junior College, Okayama, 1, 61-72.
⚬ Okubo, I. 2004. Nihon tansui san kaimijinko rui ni tsuite. Kabushikigaisha Sanmon Insatsusho, Okayama, Japan, 72pp. [In Japanese, privately published].
⚬ Okubo, I. and K. Ida 1989. Freshwater Ostracoda from Gunma Prefecture, Japan (In Japanese). Bulletin of the Biogeographical Society of Japan, 44, 105-107.
⚬ Smith, R. J., Janz, H. & Okubo, I. 2011. Recent Cyprididae and Ilyocyprididae (Crustacea: Ostracoda) from Lake Biwa, Japan, including a summary of the lake's ostracod fauna. Zootaxa, 2874, 1-37.
⚬ Whatley, R.C., Bajpai, S. & Whittaker, J.E. 2003. The identity of the non-marine ostracod Cypris subglobosa Sowerby from the intertrappean deposits of peninsular India. Palaeontology, 46, 1281-1296.

2. Cypris maculosa Bronstein, 1925

Figures in: Bronstein 1988; Okubo & Ida, 1989 (as Cypris decaryi); Okubo, 1990; 2004.
Habitat: Rice fields (Okubo & Ida 1989; Okubo 1990; 2004), temporary water bodies (Martens & Ortal 1999).
Mode of life: Nektobenthic (swimmer).
Reproduction mode: Asexual, males unknown.
Known distribution: Okayama Prefecture and Guma Prefecture (Okubo & Ida 1989; Okubo 1990). Elsewhere, Iran (Bronstein 1988; Yassini 1976) and Israel (Martens & Ortal 1999).
Notes: The Japanese specimens figured by Okubo & Ida (1989) and Okubo (1990; 2004) are significantly higher in lateral view compared with other reports from outside of Japan. The Japanese specimens need further investigation.
References:
⚬ Bronstein, Z. S. 1925. Beiträge zur Kenntnis der Ostracodenfauna U.S.S.R. und Persiens. Archiv fü Naturgeschichte, Abt. A91, 1-30.
⚬ Bronstein, Z. S. 1988. Fresh-water Ostracoda. Fauna of the USSR, Crustaceans, New Series No. 31, volume II, number I. Academy of Sciences of the USSR, Zoological Institute. New Delhi: Amerind Publishing Co. Pvt. Ltd.
⚬ Martens, K. & Ortal, R. 1999. Diversity and zoogeography of inland-water Ostracoda (Crustacea) in Israel (Levant). Israel Journal of Zoology, 45, 159-173.
⚬ Okubo, I. 2004. Nihon tansui san kaimijinko rui ni tsuite. Kabushikigaisha Sanmon Insatsusho, Okayama, Japan, 72pp. [In Japanese, privately published].
⚬ Okubo, I. and K. Ida 1989. Freshwater Ostracoda from Gunma Prefecture, Japan (In Japanese). Bulletin of the Biogeographical Society of Japan, 44, 105-107.
⚬ Okubo, I. 2004. Nihon tansui san kaimijinko rui ni tsuite. Kabushikigaisha Sanmon Insatsusho, Okayama, Japan, 72pp. [In Japanese, privately published].