Undulacandona, Smith, Robin J., 2011

Smith, Robin J., 2011, Groundwater, spring and interstitial Ostracoda (Crustacea) from Shiga Prefecture, Japan, including descriptions of three new species and one new genus, Zootaxa 3140, pp. 15-37 : 28

Genus Undulacandona n. gen.

Diagnosis. Carapace sexually dimorphic with male quadrate in lateral view, while female sub-trapezoidal. Dorsal view very compressed, beak-shaped and pointed at both ends. Surface covered with striations, left valve overlapping right valve along dorsal and ventral margins. An1 with six segments. An2 exopodite with three very short setae. Y aesthetasc long and slender. Male with second An2 endopodal segment divided and with male bristles; seta t2 greatly thickened, terminating with flattened disk structure, t3 thickened and bifurcated near distal end. L7 with d1, d2 and dp setae, and very long, reflexed h3 seta. Zenker organ with 3+2 rosettes, anterior with inflated, bulbous end. CR short, stout and curved. Hp with two terminal lobes, one longer than other and with hooked distal end.

Type species. Undulacandona spinula n. sp.

Etymology. From the Latin undula, meaning a wave, referring to the fact that the surface ornamentation of the carapace is reminiscent of small ripples or waves on the surface of the water.

Remarks. This genus is similar to Mixtacandona Klie, 1938 , a stygobite genus with a European distribution. Undulacandona can be distinguished from Mixtacandona by the number of segments in the antenna (six in Undulacandona , eight in Mixtacandona with the first two fused together), by the reduced, stout, and curved caudal ramus in Undulacandona , and the Zenker organ (with 3+2 rosettes in Undulacandona and 5+2 rosettes in Mixtacandona ). The new genus also shares some characteristics of the Australian genus Pierrecandona Karanovic, 2007 , in particular the striated carapace, similar shaped male fifth limb palps, antennal exopodite reduced to three very short setae, and six-segmented antennules. Undulacandona differs from Pierrecandona in the following characters: male antennae with sexual bristles (missing in Pierrecandona ), different shaped hemipenes, Zenker organs with 3+2 rosettes (5+ 2 in Pierrecandona ), and partially reduced caudal rami (caudal rami of ‘normal’ size and with a long spine on the Ga claw in Pierrecandona ).