Genus Pannychia Théel, 1882

[Japanese name: Hage-namako-zoku]

(Table 1)

Pannychia Théel 1882, p. 88; Fisher 1907, p. 709; Mitsukuri 1912, p. 207; Pawson 1965, p. 22; Pawson 1970, p. 53; Hansen 1975, p. 72; O’Loughlin et al. 2013, pp. 40, 43; Ogawa et al. 2022, pp. 8, 11.

Laetmophasma Ludwig, 1894, p. 85 .

Diagnosis. (Emended after Ogawa et al. 2022). Body cylindrical, lacking circum-oral papillae. Tentacles 16–20, non-retractile, with digitiform disc. Papillae numerous, slender, variable in length, present along the entire dorsal and ventral-lateral radii. Papillae not fused and formed neither ventrolateral continuous brim nor anterior dorsal irregular fringe. Tube feet on ventral-lateral and mid-ventral radii; exceptionally mid-ventral ones replaced by ventral papillae for P. moseleyi collected from the eastern Pacific (as L. fecundum in Ludwig 1893, 1894). Body wall ossicles wheels. Wheel ossicles usually in two distinctive forms: large wheels having triangular rim teeth, 4–6 central rays on connecting central portion, a calcareous membrane narrowing/ covering the nave; significantly smaller wheels, round to oval in shape, having about 10–12 spokes, usually 4 central rays, without a calcareous membrane, with/without rim teeth.

Type species. Pannychia moseleyi Théel, 1882 .

Other species included. Pannychia henrici Ludwig, 1894; Pannychia taylorae O’Loughlin in O’Loughlin et al., 2013; Pannychia virgulifera Ohshima, 1915; Pannychia nagasakimaruae sp. nov.; Pannychia rinkaimaruae sp. nov.

Remarks. The genus Pannychia is easily distinguished morphologically from the other elasipodid genera by the presence of dorsal papillae on ventral-lateral radii and large wheel ossicles with rim teeth. The two new species, Pannychia nagasakimaruae sp. nov. and Pannychia rinkaimaruae sp. nov., were consistent with these morphological characters. The four currently valid species and our two new species differed from each other by the combination of morphological characters in the arrangement of dorsal papillae, as well as the composition, density, size, and microstructure of their ossicles (see Table 1 for the details and also under Remarks sections of each new species below).