at the Lake Biwa Museum, Japan
Robin James Smith
Subfamily Entocytherinae Hoff, 1942
Superfamily: Cytheroidea Baird, 1850
Family: Entocytheridae Hoff, 1942
Two species have been reported from Japan:
1. Ankylocythere sinuosa (Rioja, 1942)Figures in: Hart & Hart 1974 (carapace and male sexual organ)
Mode of life: Commensal on the red swamp crayfish Procambarus clarkii, typically found on the gills.
Reproduction mode: Sexual.
Known distribution: Tokyo (Ohtaka et al. 2017). Elsewhere, western USA, Spain, England and the Czech Republic (see references in Ohtaka et al. 2017).
Notes: This is an invasive species in Japan, originating from the USA (Ohtaka et al. 2017).
2. Uncinocythere occidentalis (Kozloff & Whitman, 1954)
Right side view of a male (top) and female of Uncinocythere occidentalis, length 0.4 mm.
Additional figures in: Hart & Hart 1974 (carapace and male sexual organ); Smith & Kamiya 2001 (carapace and appendages).
Habitat: Lakes and rivers.
Mode of life: Commensal on the signal crayfish Pacifastacus leniusculus trowbridgii, typically found on the gills.
Reproduction mode: Sexual.
Known distribution: Hokkaido (Smith & Kamiya 2001). Elsewhere, western USA (Hart & Hart 1974), UK, Spain, France, the Netherlands and Germany (see references in Ohtaka et al. 2017).
Notes: This is an invasive species in Japan, originating from the USA (Smith & Kamiya 2001).
Hart, D. G. & Hart, Jr., C. W. 1974. The ostracod family Entocytheridae. The Academy of Natural Sciences of Philadelphia, Monograph 18, 1-239.
Smith, R. J. & Kamiya, T. 2001. The first record of an entocytherid ostracod (Crustacea: Cytheroidea) from Japan. Benthos Research, 56 (2), 57-61.
|Key characters||Uncinocythere occidentalis|
|Carapace - ventral valve overlap||Left valve overlaps right along ventral margin|
|Carapace - margin structure - septa||No septa present|
|Carapace - margin structure - ridges on inner calcified lamella||No ridges|
|Carapace - dorsal view - female with brood pouch||Brood pouch not visible|
|Carapace - lateral view - ventral margin||Ventral margin approximately straight to concave|
|Carapace - lateral view - valve height||Left and right valves similar height|
|Carapace - internal view||No calcified inner lamella|
|Carapace - ornamentation - denticles||No denticles near ventral margin|
|Carapace - ornamentation - sulcus||No sulcus|
|Carapace - ornamentation - surface||Surface smooth|
|Carapace - width/length ratio (w/l)||Less than 0.4 (slender species)|
|Antennule - segments||Seven moveable segments|
|Antennule - Rome organ||Rome organ absent|
|Antenna - exopodite||Exopodite a spinneret seta|
|Antenna - swimming setae||No swimming setae present|
|Fifth limb - morphology||Walking leg|
|Sixth limb - segments||Four segments|
|Sixth limb - setae on first segment||One seta|
|Sixth limb - h3 seta on final segment||No h3 seta|
|Seventh Limb||Walking leg, larger than sixth limb|
|Seventh Limb - segments||Four segments|
|Seventh Limb - first segment||One seta|
|Caudal ramus||Reduced to only one or two setae or absent|
|Caudal ramus - attachment||With no caudal ramus attachment|