Genus Physocypria Vavra, 1897
Superfamily: Cypridoidea Baird, 1845
Family: Candonidae Kaufmann, 1900
Subfamily: Cyclocypridinae Kaufmann, 1900
Two species have been reported from Japan:
1. Physocypria nipponica Okubo, 1990
External view of a female left valve of Physocypria nipponica, length 586 microns.
External view of a female right valve of Physocypria nipponica, length 575 microns.
The male sexual organ of Physocypria nipponica, length 162 microns.
- Additional figures in: Okubo 1990; Okubo 2004; Smith & Janz 2008; Chang et al. 2012.
- Habitat: Rice fields, and shallow areas of Lake Biwa.
- Mode of life: Nektobenthic.
- Reproductive mode: Sexual.
- Known distribution: Japan and Korea (Chang et al. 2012).
- References:
- ⚬ Chang, C. Y., Lee, J. & Smith, R. J. 2012. Nonmarine ostracods (Crustacea) from South Korea, including a description of a new species of Tanycypris Triebel (Cyprididae, Cypricercinae). Zootaxa, 3161, 1-19.
- ⚬ Okubo, I. 1990. Seven new species of freshwater Ostracoda from Japan. Researches on Crustacea, 19, 1-12.
- ⚬ Okubo, I. 2004. Nihon tansui san kaimijinko rui ni tsuite. Kabushikigaisha Sanmon Insatsusho, Okayama, Japan, 72pp. [In Japanese, privately published].
- ⚬ Smith, R. J. & Janz, H. 2008. Recent species of the Family Candonidae (Ostracoda, Crustacea) from the ancient Lake Biwa, Central Japan. Journal of Natural History, 42, 2865-2922.
- ⚬ Smith, R. J., Lee, J. & Chang, C. Y. 2014. Nonmarine Ostracoda (Crustacea) from Jeju Island, South Korea, including descriptions of two new species. Journal of Natural History, http://dx.doi.org/10.1080/00222933.2014.946110, 1-40.
2. Physocypria biwaensis (Okubo, 1990) 
Left side view of a female Physocypria biwaensis, length about 0.6 mm.
External view of a female left valve of Physocypria biwaensis, length 580 microns.
External view of a female right valve of Physocypria biwaensis , length 568 microns.
The male sexual organ of Physocypria biwaensis, length 134 microns.
- Additional figures in: Okubo 1990; Okubo 2004; Smith & Janz 2008.
- Habitat: Found at all depths of Lake Biwa.
- Mode of life: Nektobenthic.
- Reproductive mode: Sexual.
- Known distribution: Currently only known from Lake Biwa.
- References:
- ⚬ Okubo, I. 1990. Seven new species of freshwater Ostracoda from Japan. Researches on Crustacea, 19, 1-12.
- ⚬ Okubo, I. 2004. Nihon tansui san kaimijinko rui ni tsuite. Kabushikigaisha Sanmon Insatsusho, Okayama, Japan, 72pp. [In Japanese, privately published].
- ⚬ Smith, R. J. & Janz, H. 2008. Recent species of the Family Candonidae (Ostracoda, Crustacea) from the ancient Lake Biwa, Central Japan. Journal of Natural History, 42, 2865 - 2922.