Eudorylaimus vanrosseni, A..L O O F, 1971

P. A. A. LOOF, 1971, FREELIVING AND PLANT PARASITIC NEMATODES FROM SPITZBERGEN, COLLECTED BY MR. H. VAN ROSSEN, Mededelingen Landbouwhogeschool Wageningen 71, pp. 1-86 : 76-77

Eudorylaimus vanrosseni n.sp.

( Fig. 27 ; Diagram 6).

Dimensions:

Females (n = 8): L = 1.03-1.25 mm; a = 23- 29; b = 3.5-4.3; c = 35-40; V = 1 3 _ 1 854 - 5713 - 1 8.

Female, holotype: L = 1.05 mm; a = 27; b = 3.6; c = 38; V = 135615.

Male unknown.

Body rather stout, curved ventrad slightly in death. Cuticle 2.5- 3.0 [x thick, increasing to 6 u, on ventral side of tail; with thin, sharply demarcated outer layer which shows fine but distinct transverse striae. Lateral chord about 30 % of body width. Lip region offset by a shallow constriction; lips separate, angular. Amphid aperture about 60 % of corresponding body width. Length of odontostyle 16-17 (JL, i.e. slightly more than width of lip region, the aperture occupying about one-third of its length. Basal portion about 25 \i long. Guiding ring 'single'. The nerve ring surrounds the oesophagus at about 35 % of its length from head end. Cardia conspicuous, subglobular, variable in size (12-20 X 15- 27(1).

Oesophageal characters (two females): The oesophagus begins to widen at 51- 53 % and attains its full width at 57- 60 % of its length from head end. DO lies at, or just anterior to the latter level, the distance DO- DN is 13 -14 \i. The SiN lie a small distance apart, behind the middle of the distance DN - S2N; the anterior one is small and indistinct, the posterior one large and conspicuous. The S2N are well developed and lie rather close to the base of the oesophagus. Locations:

DO 57 -59 %; SjN^ 77-78 %; S2N 90-93 %; K = 85 - 93;

D N 62 -63 %; SjN2 79- 80 %; S20 92- 93 %; K ' = 94.

DO- DN 4.6 %; dist. 1.6-2.7 %;

Vulva of the transverse type, vagina wide, half body width deep. Gonads two, opposed, reflexed, without sperm; with constriction between uterus and oviduct. Tail shaped as in E.monohystera : convex-conoid, indented dorsally, tip round­ ed; its length 1.0-1.3 anal body widths. Rectum 1.2 - 1.3 anal body widths long, prerectum one to two times as long as rectum. Tail with a row of (usually 6) small ventral saccate bodies.

Holotype: Female on slide WT 1134 . Paratypes: Seven females on slides WT 1221-1224 .

Type habitat and locality: Sample 55. Paratypes also from sample 53.

Diagnosis: This species resembles E.pratensis (de Man, 1880) in tail shape, but this species has a much longer and thinner odontostyle. From E. nitidus (Thorne & Swanger, 1936) it differs by the well-developed, separate lips; from E.obesus (Thorne & Swanger, 1936) by the distal part of the tail ventrally not being offset, and by the shorter odontostyle (against 22 \x) with shorter aperture; from E.albionensis (van der Linde, 1938) by the non-sinuate ventral tail contour, lower lip region, post-equatorial vulva and lower ratio odontostyle/lip region (1.5 in albionensis ).

Figures

FIG. 27. Eudorylaimus vanrosseni n.sp.,female.A:head end; B:oesophagus base; C: vulva; D: tail; E: entire specimen.