Ostracod Research at the Lake Biwa Museum, Japan

Robin James Smith

Genus Dolerocypris Kaufmann, 1900

Superfamily: Cypridoidea Baird, 1845
Family: Cyprididae Baird, 1845
Subfamily: Dolerocypridinae Triebel, 1961

Three species have been reported from Japan:

1. Dolerocypris fasciata (O.F. Müller, 1776)

Figures in: Okubo 1972; Meisch 2000; Okubo 2004.
Habitat: Rice fields (Okubo 1972; 2004), concrete ditch, a basin, runoff of a spring, slow flowing stream in cave (Broodbakker 1988); reed bed in lake (Hiruta & Smith 2001). Elsewhere, littoral zones of lakes, reed beds, weedy fish ponds and swamps (Meisch 2000).
Mode of life: Nektobenthic (swimmer).
Reproduction mode: Asexual, males unknown.
Known distribution: Okayama Prefecture (Okubo 1972); Gunma Prefecture (Okubo & Ida 1989); Hiroshima Prefecture (Broodbakker 1988); Kagoshima Prefecture (Broodbakker 1988); Okinawa (Broodbakker 1988); Hokkaido (Hiruta & Smith 2001). Elsewhere, Holarctic (Meisch 2000).
Notes: In Japan there is a subspecies, Dolerocypris fasciata nipponensis Okubo, 1972, which differs from Dolerocypris fasciata found elsewhere in that it lacks the dorsal dark green band.
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.
⚬ Hiruta, S. & Smith, R. J. 2001. Living Freshwater and Shallow marine Ostracoda in Eastern Hokkaido, Japan (Field excursion E): 107 - 125. In: Guidebook of Excursions of the 14th International Symposium on Ostracoda (ed. Ikeya, N.). Shizuoka, Japan, 147 pp.
⚬ Meisch, C. 2000. Freshwater Ostracoda of Western and Central Europe. In: Schwoerbel, J., Zwick, P., (Eds.), Süßwasserfauna von Mitteleuropa 8/3. Spektrum Akademischer Verlag, Heidelberg, Berlin 522 pp.
⚬ Okubo, I. 1972. Freshwater Ostracoda from Japan, I. Two species of the genus Dolerocypris Kaufmann, 1900. Review of Shujitsu Junior College, Okayama, 1, 41-60.
⚬ Okubo, I. 2004. Nihon tansui san kaimijinko rui ni tsuite. Kabushikigaisha Sanmon Insatsusho, Okayama, Japan, 72pp. [In Japanese, privately published].
⚬ Okubo, I. & Ida, K. 1989. Freshwater Ostracoda from Gunma Prefecture, Japan (In Japanese). Bulletin of the Biogeographical Society of Japan, 44, 105-107.


2. Dolerocypris ikeyai Smith & Kamiya, 2006

Left side view of a female Dolerocypris ikeyai, length about 1.1 mm. In this genus, the right valve overlaps the left. The colour of the carapace varies from green through to pale green/blue to white.

External view of a female left valve of Dolerocypris ikeyai, length 1066 microns.

External view of a female right valve of Dolerocypris ikeyai, length 1078 microns.

Additional figures in: Smith & Kamiya 2006; Smith 2011; Chang et al. 2012.
Habitat: Typically found in the runoff of small springs and seeps (Smith 2011), but has also been reported from rice fields (Tanaka et al. 2015).
Mode of life: Benthic.
Reproduction mode: Sexual populations are known from two small Japanese islands, Yakushima and Tagashima. Elsewhere asexual.
Known distribution: Found throughout most of Japan (not reported from Hokkaido) (Smith 2011; Tanaka et al. 2015), 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.
⚬ Smith, R. J. 2011. Groundwater, spring and interstitial Ostracoda (Crustacea) from Shiga Prefecture, Japan, including descriptions of three new species and one new genus. Zootaxa, 3140, 15-37.
⚬ Smith, R. J. & Kamiya, T. 2006. Six new species of fresh and brackish water ostracods (Crustacea) from Yakushima, Southern Japan. Hydrobiologia, 559, 331-355.
⚬ Tanaka, H., Kotorii, H., Yokozawa, K., Wakabayashi, F., Kimoto, K. & Sano, K. 2015. Distribution and occurrence of freshwater Ostracoda (Crustacea) from southwest region of Mt. Fuji. TAXA, Proceedings of the Japanese Society of Systematic Zoology, 38, 26-41. [In Japanese with English abstract.]


3. Dolerocypris sinensis Sars, 1903

Left side view of a female Dolerocypris sinensis, length 1.9 mm. In this genus, the right valve overlaps the left.

External view of a female left valve of Dolerocypris sinensis, length 1815 microns.

External view of a female right valve of Dolerocypris sinensis, length 1877 microns.

Additional figures in: Okubo 1972; Okubo 2004.
Habitat: Often found in rice fields (Okubo 1972), but also reported from concrete containers, ditches, ponds, an open well, and a spring/puddle (Broodbakker 1988).
Mode of life: Nektobenthic (swimmer).
Reproduction mode: Asexual, males unknown.
Known distribution: Widespread in Japan (Okayama (Okubo 1972), Gumma (Okubo & Ida 1989), Hiroshima, Yamaguchi and Kagoshima Prefectures and Okinawa (Broodbakker 1988)). Elsewhere, Eurasia (Meisch 2000).
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.
⚬ Meisch, C. 2000. Freshwater Ostracoda of Western and Central Europe. In: Schwoerbel, J., Zwick, P., (Eds.), Süßwasserfauna von Mitteleuropa 8/3. Spektrum Akademischer Verlag, Heidelberg, Berlin 522 pp.
⚬ Okubo, I. 1972. Freshwater Ostracoda from Japan, I. Two species of the genus Dolerocypris Kaufmann, 1900. Review of Shujitsu Junior College, Okayama, 1, 41-60.
⚬ Okubo, I. 2004. Nihon tansui san kaimijinko rui ni tsuite. Kabushikigaisha Sanmon Insatsusho, Okayama, Japan, 72pp. [In Japanese, privately published].