Hydrichthella ocellata Xu, Huang & Wang, 2017

Wang, Lianggen, Du, Feiyan, Xu, Zhenzu, Huang, Jiaqi & Guo, Donghui, 2017, Taxonomical notes on the family Ptilocodiidae (Anthomedusae) from the central and southern of South China Sea, with a new genus and a new species, Zoological Systematics 42 (2), pp. 236-242 : 238-239

Hydrichthella ocellata Xu, Huang & Wang , sp. nov. ( Figs 1–4 )

Material examined. Holotype SFI 001 , southern of South China Sea, st. B4 (10°16'N, 114°13'E), depth 2000 m, sampling depth 20–0 m, 22 May 2014, colls. Shen Chen & Jie Li ( SFRI).

Diagnosis. Free eumedusoid, umbrella nearly spherical; with short and wide gastric peduncle, with 4 large mass-like gonads, interradial on manubrium; bell margin with 8 non-tentacular bulbs, 4 perradial larger than 4 interradial bulbs, each with a distinct red ocellus at the extreme tip.

Description. Medusa reduced to short-living eumedusoid; umbrella up to 1 mm high, nearly as wide as high in preserved specimen; mesoglea about 1/3–1/4 diameter of exumbrella; exumbrella covered with nematocysts, without exumbrellar furrows and didermic centripetal tracks; manubrium hanging from short and wide peduncle, mouth more or less quadratic in shape with simple mouth lips; 4 gonads interradial, extending to adradial on manubrium, smooth without folded; with 4 radial canals and circular canal; umbrella margin with 8 non-tentacular bulbs, 4 perradial larger than 4 interradial bulbs, each with a distinct red ocellus at the extreme tip; velum middle broad.

Hydroid. Unknown.

Distribution. Southern South China Sea.

Etymology. The specific name refers to the Latin ocellata , meaning ocellus. The eumedusoid name refers to the marginal bulbs each with a red ocellus at the extreme tip.

Remarks. Although only one specimen was found, its good preservation of morphological characters suggests that a new eumedusoid is present. The eumedusoid of Hydrichthella ocellata Xu, Huang & Wang , sp. nov. is very similar to the eumedusoid of H. epigorgia Stechow, 1909 (redescribed by Hirohito (1988)), by the bearing eumedusoids with four radial canals, 8 marginal bulbs, 4 large, mass-like gonads, interradial positions on manubrium, with velum. But the eumedusoid of H. ocellata Xu, Huang & Wang , sp. nov. is clearly different from H. epigorgia by free swimming eumedusoid with exumbrellar scattered nematocysts, with a short and wide gastric peduncle, 8 marginal bulbs, 4 perradial bulbs larger than 4 interradial bulbs, each with a red ocellus at the extreme tip ( Figs 1–4 ).

Figures

Figures 1–4. Hydrichthella ocellata Xu, Huang & Wang, sp. nov. 1–3. Lateral view. 4. Oral view. Scale bars=0.5mm.