Entomelas dujardini (Maupas, 1916) Travassos, 1930

KUZMIN, YURIY, 2013, Review of Rhabdiasidae (Nematoda) from the Holarctic, Zootaxa 3639 (1), pp. 1-76 : 58-60

Entomelas dujardini (Maupas, 1916) Travassos, 1930

( Fig. 31 E–H )

Synonyms: Angiostoma entomelas Dujardin, 1845 (part.), Rhabdias dujardini Maupas in Seurat, 1916; Entomelas entomelas ( Dujardin, 1845) (sensu Baker 1980, part.).

Host: Anguis fragilis ( Reptilia: Sauria : Anguidae ).

Site: lungs.

Distribution: Western Palaearctic.

Description. Adult hermaphrodites. Body length 5.06 (2.75–8.50) mm, maximum width 197 (107–332). Body cuticle swollen, especially in anterior part. Oral opening round. Teeth small. Three of six teeth partially reduced and poorly visible in lateral view. Buccal capsule 23 (18–28) deep and 28 (25–30) wide. Anterior end of oesophagus approximately as wide as buccal capsule. Oesophagus club-shaped, 444 (274–664) long (9.0 [5.5– 14.8] % of body length). Width of posterior bulb 63 (48–86). Nerve ring at 140 (130–160) from anterior end of oesophagus (32.1 [26.5–37.2] % of oesophagus length). Excretory pore situated behind level of nerve ring. Excretory glands shorter than oesophagus. Intestine wide, thick-walled. Contents of intestine black in posterior part. Distance from anterior end to vulva 2.51 (1.50–3.75) mm (49.8 [42.6–56.4] % of total length). Uteri wide, filled with numerous eggs. Eggs in uteri of some species containing completely developed larvae. Tail with prominent thin cuticular needle on the end. Tail length 192 (125–249), or 3.9 (2.9–4.9) % of body length.

Subadult hermaphrodites differing from adults by thin, smooth body cuticle and smaller body size. Body length 2.85 (2.58–3.32) mm, maximum width 98 (92–107). Buccal capsule 21 (20–22) deep and 29 (27–30) wide. Oesophagus 412 (381–437) long (14.5 [12.4–17.0] % of body length). Width of oesophageal bulb 53 (50–57). Nerve ring at 135 (119–144) from anterior end of oesophagus (32.7 (29.7–35.9) % of oesophagus length). Excretory glands prominent. Intestine comparatively narrow, straight. Vulva at 154 (1.42–1.66) mm from anterior end (54.2 [48.4–56.4] % of general length). Vulva lips distinct. Uteri narrow, empty. Tail conical, 140 (125–172) long, or 4.9 (4.4–5.4) % of body length. Tail end tapered, apical cuticular needle sometimes less prominent than that in adult worms.

Biology. Life cycle is of rhabdiasoid type. Free-living females have maximum 3 eggs in uteri. Usually 2 larvae develop in each female (matricidal hatching). Infective larvae were able to infect terrestrial snails Deroceras sp. and Arion sp. ( Kuzmin and Sharpilo 2000). Oral injection of infective larvae resulted in successful development of hermaphrodites in the host. Larvae migrated from digestive tube to body cavity and, thereafter, penetrated lungs. Experimental hyperinfection resulted in arrested development of hermaphrodites in the body cavity.

Material studied: over 200 specimens ( SIZK) from various localities. Thirty-eight adult and 15 subadult specimens were measured .

References: Dujardin (1845), Maupas in Seurat (1916), Travassos (1930), Hartwich (1975), Sharpilo (1976), Kuzmin and Sharpilo (2000).

Figures

FIGURE 31. A—E. entomelas, head end, lateral view; B—E. entomelas, tail end, lateral view; C—E. entomelas, head end, apical view; D—E. entomelas, anterior part of body, lateral view; E—E. dujardini, anterior part of body, lateral view; F—E. dujardini, head end, lateral view; G—E. dujardini, head end, apical view; H—E. dujardini, tail end, lateral view. Scale bars: A...D, H—0.1 mm; E—0.2 mm; F—0.05 mm; G—0.025 mm.