Rhabdias elaphe Sharpilo, 1976

KUZMIN, YURIY, 2013, Review of Rhabdiasidae (Nematoda) from the Holarctic, Zootaxa 3639 (1), pp. 1-76 : 37

Rhabdias elaphe Sharpilo, 1976

( Fig. 18 )

Hosts: Zamenis hohenackeri , Z. longissimus ( Reptilia: Serpentes: Colubridae ), occasionally Lacerta viridis ( Reptilia: Sauria : Lacertidae ).

Site: lung.

Distribution: Western Palaearctic. Western, Central and Eastern Europe, Caucasus.

Description: Body length 5.21 (3.57–6.35) mm, maximum width 222 (132–299). Body cuticle thin, its outer surface transversely striated. Six cephalic lips arranged in two lateral groups. Oral opening wide, round. Vestibulum absent. Buccal capsule wide, funnel-shaped, 10 (8–12) deep and 24 (22–26) wide. Buccal capsule walls free from oesophageal tissue. Oesophagus comparatively wide, club-shaped, 311 (274–332) long (6.2 [4.5–8.6] % of body length). Posterior bulb of oesophagus 76 (60–92) wide. Nerve ring situated 147 (116–174) from anterior end of oesophagus (47.4 [36.8–54.0] % of oesophagus length). Excretory glands prominent, approximately as long as oesophagus. Intestine wide, its anterior end usually wider than posterior bulb of oesophagus. Rectum prominently sclerotised. Vulva situated at 2.39 (1.70–3.07) mm from anterior end (46.5 [39.5–51.6] % of total length). Eggs numbering 64 (27–107) in gravid specimens, containing embryos on early cleavage stages. Egg size 88–99 × 41–46 (after Sharpilo 1976). Tail wide, conical, 204 (149–249) long (4.0 [3.2–5.6] % of body length). Tail end tapered.

Biology (after Kuzmin and Miskov 1999). Life cycle is of strongyloid type. Homogony predominates with average ratio of homogonic:heterogonic stages 11:1. In the gonochoristic generation, males are more numerous than females (average ratio 2.6:1). Matricidal hatching is absent in the development of free-living generation’s offspring. Homo- and heterogonic infective larvae are similar in morphology. Development in the specific host was not studied; juveniles were able to develop up to the subadult stage in experimentally infected grass snake, Natrix natrix (Colubridae) .

Material studied: 29 specimens measured ( SIZK), including 22 specimens from Z. longissima (13 from Carpathian Mountains , 9 from the Black Sea northern coast, Ukraine), 4 specimens from Z. hohenackeri ( Armenia) and 1 specimen from L. viridis (Carpathian Mountains, Ukraine); 37 specimens from France ( MNHN, 139Q) .

References: Sharpilo (1976), Lewin (1993), Kuzmin and Miskov (1999).

Figures

FIGURE 18. R. elaphe. A—gravid specimen, anterior part of body, lateral view; B—head end, apical view; C—tail end, lateral view; D—subgravid specimen, anterior part of body, lateral view; E—subgravid specimen, tail end, lateral view. Scale bars: A, D—0.2 mm; B—0.05 mm; C, E—0.1 mm.