Podocorynoides minima ( Trinci, 1903 )

Wang, Chunguang, Xu, Zhenzu, Huang, Jiaqi, Guo, Donghui, Lin, Mao & Xia, Zhen, 2016, Taxonomic notes on Hydroidomedusae (Cnidaria) from South China Sea III: Family Rathkeidae and Zancleopsidae, Zoological Systematics 41 (4), pp. 392-403 : 398

Podocorynoides minima ( Trinci, 1903) ( Fig 15 )

Cytaeis minima Trinci, 1903: 26–28 , pl. 1, figs 1–30. Podocoryne simplex Kramp, 1928: 45 , fig. 20; Russell, 1953b: 136; Kramp, 1961: 70; 1968: 28, fig. 70; Zhang & Liu, 1999: 25, 28, fig.

6. Podocoryne minima Russell, 1953b: 134 , Figs 63–64; Chow & Huang, 1958: 176, pl. 1, figs 10–11; Kramp, 1961: 69; 1968: 28, fig. 69;

Brinckmann-Voss, 1970: pl. 7, fig. 1; Zhang, 1979: 129; Lin, 1989: 60; Lin & Zhang, 1990: 431; Huang et al., 1991: 465; Li &

Chen, 1991: 2, 14, fig. 17; Jiang & Chen, 1994: 19; Lin, 1994: 169; Wang, 1996: 44; Ma & Gao, 2000: 535; Wang et al., 2005: 275. Pododoryna minima Schuchert, 1996: 50 , fig. 27. Hydractinia minima Bouillon et al., 2004: 65–66 , fig. 39D–E; Bouillon et al., 2006: 150; Xu et al., 2006: 117; Guo et al., 2008: 230; Du et al., 2010: 74; Xu et al., 2014: 258, fig. 116.

Material examined. Daya Bay, May and August 1989, about abundance 0–5 ind./m 3, initially identified as Podocoryne minima ; Changjiang River estuary, 14 June 2003 and Beibu Gulf, 15 July 2006, about abundance 0–0.4 ind./m 3, initially identified as Hydractinia minima .

Diagnosis. See genus diagnosis.

Description. Medusae with dome shaped or globular bell; apical jelly slightly thickened in fully grown animals; relatively long gastric peduncle present (up to 1/3 of bell cavity); with four radial canals and a rather narrow ring canal; with four perradial marginal bulbs and tentacles, without ocelli; adaxial epidermis of bulbs thickened and pad-like, gastrodermis with or without brown pigment, tentacles very contractile; manubrium with cylindrical shape, length 2/3 of bell cavity, perradial lip margins elongated to short oral tentacles terminating in a spiny, spherical knob of nematocysts; interradial medusa buds on manubrium with ordered budding sequence; gonads surrounding manubrium completely.

Dimensions. Bell size 0.3–1.0 mm (Uchida & Sugiura, 1977; Chow & Huang, 1958; present work).

Biology. The medusa is a circumtropical species. In more subtropical ( Taiwan Strait and northern of South China Sea) and tropical (middle-southern of South China Sea) waters of China Sea, they can be found all year round, but mostly abundant in May to October ( Lin, 1989, 1994; Li & Chen, 1991; Xu et al., 2006). A quite rare medusa is recorded in the north temperate waters of China Sea (Bohai Sea and Yellow Sea) during July to August ( Chow & Huang, 1958; Jiang & Chen, 1994). In the Mediterranean, the medusa is present at least during March to September ( Trinci, 1903; Brinckmann-Voss, 1987).

Distribution. The medusa is widespread, it occurs in the China Sea from Bohai Sea, Yellow Sea ( Chow & Huang, 1958; Jiang & Chen, 1994), East China Sea ( Wang et al., 2005; Xu et al., 2006), Taiwan Strait ( Lin, 1994), northern of South China Sea ( Lin, 1989; Guo et al., 2008) to middle and southern of South China Sea (Li & Chen, 1991). An oceanic medusa recorded from Mediterranean ( Trinci, 1903), English Channel (Russel, 1953b), Brazil (Vanucci, 1957), North Carolina ( Allwein, 1967), Red Sea ( Schmidt, 1973), New Zealand ( Schuchert, 1996), Papua New Guinea ( Bouillon, 1980), Northwestern Pacific ( Kramp, 1928; Uchida & Sugiura, 1977).

Remarks. Although the oral tentacles of this species resemble much the Podocoryna type, it is closer related to the Rathkeidae than the Hydracitiniidae based on 16S sequence data and morphological characters of oral tentacles ( Schuchert, 2007). The oral tentacles are mostly held in a nearly vertical position, thus somewhat unlike the oblique oral tentacles of Lizzia blondina . Therefore, it is attributed to Podocorynoides minima by Schuchert (2007). The name, Podocoryne / Hydractinia minima , previously recorded from China Sea was revised as Podocorynoides minima ( Trinci, 1903) .

Figures

Figure 15. Podocorynoides minima (Trinci, 1905), in lateral view. Scale bar =0.5mm.