Euphysora knides Huang, 1999

Wang, Xuefeng, Lin, Kun, Xu, Zhenzu, Guo, Donghui & Huang, Jiaqi, 2019, Some new Hydroidomedusa (Cnidaria) from the northern South China Sea, Zoological Systematics 44 (3), pp. 191-205 : 200

Euphysora knides Huang, 1999 stat. rev. ( Figs5 , 12 )

Euphysora knides Huang, 1999: 437–438 , fig. 2; Xu et al., 2006:117; Guo et al., 2008: 230; Tang & Gao, 2008: 307; Du et al., 2010: 74; Xu et al., 2012: 298, figs. 3, 39.

non. Euphysora verrucosa Bouillon, 1978: 265–266 , fig. 11, pls. I, fig. 3; Bouillon et al., 2006: 230.

Material examined. Holotype (AOB-HL111) and paratype (AOB-HL112) collected from the Minnan-Taiwan Bank in July 1988; two specimens (AOB-HL326–327) collected from Dapeng Bay , northern of the South China Sea, station V 4 (22°35 ˊ N, 114°19 ˊ E), depth 13.5 m, 26 August 2018, coll. Zike Zhao, Guanjie Min and Shihao Deng.

Diagnosis. The species is different from others by following: umbrella bell-shaped, with a slight rounded apical projection; exumbrella with scattered cnidocyst clusters and without wart process and red brown pigment; manubrium cylindrical, above manubrium a distinct elliptical apical chamber; gonads encircling almost the whole manubrium with irregular fold; principal tentacle very long, with 20–30 abaxial knobs of cnidocysts and no clearly large terminal knob.

Description. Umbrella bell-shaped, 1.1–1.5mm in height, 0.6–0.8 mm in width, jelly thicker at apex, but thinner toward bell margin, with a slightly rounded apical projection; exumbrella with scattered cnidocyst clusters and without wart processes and red brown pigment; manubrium cylindrical, above manubrium a distinct, elliptical apical chamber, about 1/2 height of bell cavity; mouth simple circular; gonads encircling almost whole manubrium with irregular fold; principal tentacle very long, with 20–30 abaxial knobs of cnidocyst and no clearly large terminal knob; bulb of principal tentacle large, nearly spherical, three other marginal bulbs quite rudimentary, very small, all alike, papilla-like, without filiform tentacles; with 4 radial canals and ring canal; velum moderately broad.

Distribution. Minnan-Taiwan Bank of the southern Taiwan Strait; Datan Bay of Hong Kong ( Huang, 1999); Dapeng Bay of Shenzhen and Beibu Gulf of the northern South China Sea ( Guo et al., 2008; Du et al., 2012); Changjiang River Estuary of the East China Sea (Xu et al., 2006).

Remarks. The species was erected by Huang (1999) from the southern Taiwan Strait. Base on the literature’s description of E. knides and his own material of E. verrucosa Bouillon, 1978 from the Papua New Guinea, Bouillon et al. (2006) suggested these two species might be conspecific, and E. knides Huang, 1999 was regarded as a synonym of E. verrucosa Bouillon, 1978 .

However, according to the examined specimens from the Dapeng Bay, northern of the South China Sea, the species differs from E. verrucosa ( Fig. 13 ) by followings: 1) umbrella with apical projection, exumbrella covering dense cnidocysts, but without wart processes and brown pigment; 2) manubrium cylindrical, above manubrium with gastric chamber; 3) gonads encircling whole manubrium with irregular fold. As a result, Euphysora knides Huang, 1999 is treated as a valid species here.

Figures

Figures 1–6. Hydroidomedusa spp. 1. Nubiella terminaliknoba Xu, Huang & Guo, sp. nov., lateral view. 2. Paranubiella shenzhenensis Xu, Guo & Wang, sp. nov., lateral view. 3. Eucodonium crassonemalis Xu, Guo & Lin, sp. nov., lateral view. 4. Proboscidactyla trifurcata Xu, Huang & Guo, sp. nov., lateral view. 5. Euphysora knides Huang, 1999, lateral view. 6. Monocanna ovale (Mayer, 1900) comb. nov., oral view. Scale bars: 1=0.2mm; 2–3, 5–6=0.5mm; 4=1.0mm.

Figures 12–16. Hydroidomedusa spp., line drawing. 12. Euphysora knides Huang, 1999, lateral view. 13. Euphysora verrucosa Bouillon, 1978, lateral review (after Bouillon, 1978). 14. Monocanna ovale (Mayer, 1900) comb. nov., oral view. 15. Ditto, lateral view (after Mayer, 1910). 16. Gastroblasta timida Keller, 1885, oral view (after Mayer, 1900). Scale bars: 12, 14= =0.5 mm; 13 = 1.0mm.