(Fig. 23)

Synonyms: Rhabdias sp. in Kagei and Kifune (1977).

Hosts: Elaphe quadrivirgata (type host), E. climacophora (Reptilia: Serpentes: Colubridae).

Site: lung.

Distribution: Eastern Palaearctic (Kurily and Japanese Isles).

Description. Body length 3.84 (3.17–5.10) mm, maximum width 169 (149–207). Body cuticle thin. Cephalic lips small, arranged in 2 lateral groups. Vestibulum reduced. Buccal capsule cup-like, 13 (10–14) deep and 20 (20– 22) wide. Oesophagus club-shaped. Width of posterior bulb 58 (52–64). Nerve ring situated at 144 (124–149) from anterior end of oesophagus (49.3 [44.1–52.9] % of oesophagus length). Excretory pore behind the level of nerve ring. Excretory glands somewhat shorter than oesophagus. Intestine wide, intestine walls comparatively thin. Rectum prominently sclerotised. Vulva at 1.83 (1.58–2.47) mm from anterior end (47.8 [41.9–51.0] % of total length). Eggs numbering 20–40, egg size 82–88 × 44–50 (after Sharpilo 1976). Tail elongated, 175 (124–216) long (4.6 [3.3–6.0] % of body length). Tail end tapered.

Remarks. Morphological differentiation of R. kurilensis from closely related R. elaphe is rather difficult. In the first description (Sharpilo 1976) the two species were separated by the differences in buccal capsule depth. However, in the material studied this character largely overlapped in samples of R. kurilensis and R. elaphe. Two species differ in the position of excretory pore, which is situated at the level of posterior edge of nerve ring in R. elaphe, and at some distance behind the level of nerve ring in R. kurilensis. This character, however, is not constant enough in Rhabdias spp. to be used for valid species differentiation. On the other hand, the two species are well separated geographically, occurring in the opposite parts of Palaearctic.

Material studied: 18 specimens (SIZK) from Elaphe quadrivirgata and E. climacophora (Kunashir Island, Russia).

References: Kagei and Kifune (1977), Sharpilo (1976).