Gordionus chinensis ( Villot, 1874 )

Schmidt-Rhaesa, Andreas & Karraker, Nancy E., 2017, Nematomorpha from Hong Kong and description of a new species from Malaysia, Zootaxa 4238 (3), pp. 395-405 : 402-403

Gordionus chinensis ( Villot, 1874)

( Figure 4 )

Material examined. One male and one female, the female is from Tai Mo Shan stream in Tai Mo Shan Country Park, Hong Kong (UTM Zone 50Q 2482514N/203818E), elevation 565 m . Collected by N.E. Karraker on June 4, 2009. The male is from Lau Shui Heung stream, Hong Kong (2492632N/207331E), elevation 80 m . Collected by N.E. Karraker on May 18, 2010. Deposited in the Zoological Museum Hamburg, accession numbers V13402 (female) and V13403 (male).

Description. The specimens measure 220 (female) and 200 (male) mm and have a diameter of 0.7 and 0.6 mm, respectively. The length measurement of the male is a minimal count, because the anterior end is missing. The body color is light brown. The cuticle contains one type of areole. These are roughly polygonal and differ in size ( Fig. 4 A, B). Between the areoles are small knob-like structures ( Fig. 4 A, B). These are usually in the center of the edges of two neighboring areoles. The edge may be slightly indented at the position of the knobs. The knobs are not always strictly in the center of an edge, but may be shifted towards the sides.

The female posterior end is slightly swollen, and the cloacal opening is terminal ( Fig. 4 D). The male posterior end ( Fig. 4 C, E) is not in good condition. It has very smooth areas, which are likely artificial. Spines that must be present in this region could not be observed. Few spines from the anterolateral bristlefields (a common character in the genus) were observed, but these were also not well preserved. What is present are the circumcloacal spines ( Fig. 4 E). The oval cloacal opening is surrounded by a number of blunt spines. Some of these spines are artificially covered by some material. As far as could be observed all spines are unbranched.

Remarks. The cuticular pattern of the specimens fits exactly to the description of Gordionus chinensis . The first, male specimen of this species was collected by Father Armand David during his stay in Beijing (Peking), China and brought to the Muséum National d´Histoire Naturelle in Paris, where it was investigated and described by Villot (1874). Dorier (1946) later restudied this specimen. Camerano (1895, 1896) assigned a few specimens from Borneo ( Indonesia), Western China (as Kaschgaria), Kyrgyzstan and Turkestan to this species but later ( Camerano 1897) retreated from this determination. Gordionus chinensis is also reported from Japan (Schmidt- Rhaesa & Sato 2009, Schmidt-Rhaesa et al. 2009). Dorier (1946) and Schmidt-Rhaesa & Sato (2009) reported the circumcloacal spines to be partly branched, whereas in the Hong Kong specimen all spines appeared unbranched.

Figures

FIGURE 4. Gordionus chinensis, V 13402 (female) and V 13403 (male). A, B. Cuticular structure in male (A) and female (B). C. Posterior end of the male with ventral cloacal opening (co). D. Posterior end of the female with terminal cloacal opening (co). E. Cloacal opening of the male with circumcloacal spines (ccs).