Paranymphon spinosum Caullery 1896

Wang, Jianjia, Lin, Heshan, Huang, Dingyong, Zheng, Xinqing, Liu, Qinghe, Wang, Jianjun, Niu, Wentao & Zhang, Feng, 2020, Recent collections of sea spiders (Arthropoda: Pycnogonida) from China seas, with some new records and a checklist of the area, Zootaxa 4802 (2), pp. 361-373 : 363

Paranymphon spinosum Caullery 1896

( Fig. 2-i )

Paranymphon spinosum Caullery, 1896: 361–362 , pl. 12: figs. 1–6; Hedgpeth, 1948: 253, fig. 41; Stock, 1978: 204–205, fig. 5d–g; Nakamura and Child, 1983: 38; Bamber, 1983: 69, fig. 3 (B); Stock, 1986: 413 [text], fig. 4; Hong and Kim, 1987: 149–150, figs. 8, 9; Child, 1992: 8 (key), 9 (table), 31–33, fig. 14; Bamber and Thurston, 1995: 129 (key), 132.

Material examined Male (TIO2016DH0501), East China Sea , 28.41°N 123.67°E, 79 m depth, 12 Dec. 2016; Male (TIO2019Y1101), Xiamen, Fujian, China, 24.50°N 118.28°E, 0.6 m depth, 1 Jun. 2019, Yaqin Huang & Kun Liu .

Distribution This species was usually collected from the North Atlantic, but had also been reported in the Northwest Pacific, including the Western Yellow Sea, Western Kyushu and Eastern Honshu ( Nakamura & Child, 1991). Our specimens extended the species distribution to the Southwest Pacific.

Remarks There were just four species in genus Paranymphon ( Bamber et al. 2020) , and the characteristics for determining and distinguishing them were distinctive. P. spinosum was very similar to P. magnidigitatum Hong & Kim, 1987 with larger chela fingers and two tubercles on the first coxa, and could be easily distinguished with the other two speices, P. filarium Stock 1986 and P. bifilarium Arango, 2009 which shared the presence of long filiform spurs ( Arango 2009).

The stellate spines of lateral processes agreed with illustrations of P. magnidigitatum (Fig. 10c in Hong & Kim 1987) and were different from the Stock’s figures for P. spinosum (Fig. 5g in Stock 1978). The formula of compound spines on the terminal oviger articles was 4: 4: 1: 1, and slightly different from the illustrations in Hong & Kim (1987) which was 4: 4: 2: 1. The swelling of the second palp article was present on the lateral surface ( Fig. 2-i ), and different from the figure in Hong & Kim (1987, Fig. 8b) which appeared in ventral view. The third article, slightly longer than the second one, was the longest palp article.

Stock (1978) described P. spinosum as “a variable species” and supposed the variations depend on the age, and also found the differences between the materials from the West Indian and the type location, the Bay of Biscay ( Stock 1986). Given the lack of significant differences and the variations in this species, we consider that this specimens should be temporarily attributed to P. spinosum .

Figures

FIGURE 2. Propallene sp. (TIO2016CNHD3101) female, a. trunk, dorsal view; b. oviger; c. terminal articles of oviger, enlarged; d. compound spines on terminal articles of oviger, enlarged; e. chela; f. Leg 3; g. tarsus, propodus and claw of leg 3, enlarged; Propallene sp. indet., (TIO908XM2901) Juvenile, h. tarsus, propodus and claw of leg 3, enlarged; Paranymphon spinosum (TIO2016DH0501) male, i. palp, dorsal view. Scale bars a, f=0.5 mm, b, g, i=0.2 mm, c, e, h=0.1 mm.