Review of Rhabdiasidae (Nematoda) from the Holarctic Author KUZMIN, YURIY text Zootaxa 2013 2013-04-16 3639 1 1 76 http://dx.doi.org/10.11646/zootaxa.3639.1.1 journal article 10.11646/zootaxa.3639.1.1 1175-5326 5262629 32584FBD-212B-4042-BCEF-04C698D71117 Rhabdias americanus Baker, 1978 ( Fig. 14 ) Hosts: Anaxyrus americanus , A. cognatus , A. debilis , A. hemiophrys , A. microscaphus , A. retiformis , A. woodhousii , Incilius alvarius ( Amphibia : Anura : Bufonidae ), Scaphiopus couchii , Spea multiplicata (Scaphiopodidae) . Site: lungs. Distribution: Nearctic. From southern Canada to New Mexico in the U.S. A.. Description (after Kuzmin et al. 2003 , modified). Body elongated. Body length 12.46 (10.74–14.14) mm, maximum width 265 (210–310). Body cuticle inflated, especially on anterior and posterior parts. Oral opening oval-shaped. Pseudolabia comparatively large, elongated. Submedian lips small. Buccal capsule depth 10, width 13 (12–15). Oesophagus elongated, 804 (770–870) long, (6.5 [5.8–7.3] % of body length), with anterior dilation at middle of muscular part. Oesophagus width 40 (37–42) at anterior end, 52 (50–57) at middle of muscular region, 48 (45–50) at middle of glandular region; posterior bulb 82 (75–90) wide. Nerve ring at 199 (180–210) from anterior end of oesophagus (24.8 [22.8–27.3] % of oesophagus length). Distance from anterior end to vulva 6.27 (5.35–7.25) mm (50.3 [47.9–52.2] % of body length). Tail 493 (450–550) long (4.0 [3.3–4.5] % of body length). Cuticular inflation reaching tail tip. FIGURE 13. R. ambystomae : A—anterior part of body, lateral view; B—head end, lateral view; C—head end, apical view; D—tail end, lateral view. Scale bars: A—0.1 mm; B, C—0.05 mm; D—0.2 mm. FIGURE 14. R. americanus . A—anterior part of body, lateral view (outer layer of cuticle mostly excluded); B—tail end, lateral view. Scale bars: 0.1 mm. Material studied: 13 specimens from A. americanus , SIZK. References: Baker (1978 , 1979 ), Goldberg and Bursey (1991) , Goldberg et al. (1995 , 1996 ), Bursey and Goldberg (1998) , Bolek and Coggins (2000) , Kuzmin et al. (2003) .