Chitwoodiellus nipponi Ahmad and Araki, 2003

Ahmad, Wasim, Park, Byeong-Yong, Lee, Jae-Kook & Choi, Dong-Ro, 2009, Some new and known species of Tylencholaimoidea (Nematoda: Dorylaimida) from Korea, Journal of Natural History 43 (37 - 38), pp. 2329-2356 : 2343

Chitwoodiellus nipponi Ahmad and Araki, 2003

( Figure 6A–G ; Table 4)

Description

Female. Lip region cap-like, offset by deep constriction, about twice as wide as high and about half as wide as body width at neck base. Lips moderately separate, with their inner part elevated. Labial and cephalic papillae distinct. Amphids large, stirrup-shaped, their aperture occupying almost entire lateral surface. Cheilostome a truncate cone with thickened wall ending in a simple guiding ring. Distinct cuticularized plates present at the perioral region. Odontostyle relatively slender, 0.7–0.8 times the lip region width long with aperture about one-quarter to one-third of its length. Odontophore rod-like with distinct basal swelling, 1.4–1.7 times the odontostyle length; ellipsoidal swelling forming a spindle-shaped chamber. Guiding ring at 0.6–0.7 times the lip region width from anterior end. Pharyngeal expansion abrupt; expanded portion occupying about 33–36% of total neck length. Cardia elongateconoid. Genital system monodelphic–prodelphic; posterior branch represented by a very small sac, measuring 8–11 µm. Vagina anteriorly directed, about half of the corresponding body width deep. Tail short conoid to hemispheroid with distinctly enlarged hyaline area. Caudal pores two on each side.

Male. Not found

Habitats and localities

Soil samples collected from around the roots of forest trees from: (1) Ulleungdo, Gyeongsangbuk-do; (2) Jungmisan Mt, Yangpyeong-gun, Gyeongi-do; and (3) Gayasan Mt, near Haeinsa temple, Habcheon-gun, Gyeongsangbuk-do. All localities in South Korea .

Remarks

Chitwoodiellus nipponi Ahmad and Araki, 2003 is an atypical species of the rare genus Chitwoodiellus Jiménez-Guirado and Peña-Santiago, 1992 in the absence of the characteristic isthmus-like portion at the junction of two parts of the pharynx and in having a monodelphic–prodelphic female genital system. Out of five known species representing this genus, only C. nipponi is monodelphic while the other four are didelphic. Three of these species, C. gracilis , C. heynsi and C. parafuscus , have been recorded only from Europe ( Spain); C. fuscus only from Australia and C. nipponi from Japan and now from Korea. Although the Korean specimens completely fit the description and measurements of the Japanese specimens, the range of measurements and ratios are further extended.

Figures

Figure 6. (A–G) Chitwoodiellus nipponi Ahmad and Araki, 2003. (A,B) Anterior regions; (C) pharyngeal expansion; (D) pharyngo-intestinal junction; (E) vulval region; (F,G) female posterior ends. (H–L) Chitwoodielloides japonicus Ahmad and Araki, 2003. (H) Anterior region; (I) pharyngeal expansion; (J) pharyngo-intestinal junction; (K) vulval region; (L) female posterior end.