Panagrolaimus papillosus, 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 : 29-31

Panagrolaimus papillosus n.sp.

( Fig. 5 ).

Dimensions:

Females (n = 40): L = 0.59 mm (0.51-0.69); a = 22 (20-25); b = 3.9 (3.4 - 4.5); c = 19 (17- 21); V = 64 (62- 66); G^ = 22 (17-29); Gi _ 2 = 22 (13-25); G2 = 4 (3-5).

Female, holotype: L = 0.59 mm; a = 20; b = 4.1; c = 19; V = 64; G ^ = 20; G i _ 2 = 20; G2 = 3.

Male not found.

Body stout, slightly bent to ventral side in death; tapering towards both extremities. Cuticle very thin, transverse striation hardly perceptible on the outside of the cuticle. Lateral field with two wings (three longitudinal lines). Lip region one-quarter as wide as body at base of oesophagus; with six rounded lips, each bearing a large, forward pointing papilla. Mouth cavity panagrolaimoid; length of cheilorhabdions 2.5 \x, of prorhabdions about 3 -3.5 \i, of mesorhabdions about 2 jx. Corpus of oesophagus cylindroid, thrice as wide and twice as long as isthmus. Terminal bulb measuring 16 X 24 jx, its width equal to three-fifths of the corresponding body diameter. The nerve ring lies in, or slightly posterior to, the middle of the isthmus. Hemizonid and excretory pore at level of nerve ring or slightly behind it. Deirids conspicuous, located at about the same level as excretory pore.

Vulva lips strongly protruding. Vagina with sclerotization in the form of two thick dots on optical section. Uterus symmetrical. The ventrosublateral walls of the posterior chamber are thickened; in ventral view this chamber appears indented terminally. No further gonad tissue is attached to this posterior uterus. The anterior uterus bears a normal panagrolaimid gonad, in which no sperm was found; at the flexure there is a large empty spermatheca. The postvulval part of this gonad occupies usually 65-75 % of the vulva-anus distance. Rectum about as long as anal body width. Tail plump, convex-conoid to acute terminus, about two anal body diameters long. Posterior anal lip large: behind it the tail is constricted ventrally. Dimensions of four intra-uterine eggs (one per female): 50-62 x 20-23 \L \ one female bears two eggs, size 36 x 18 [x and 46 x 19 [x.

Holotype: Female on slide WT 1101 . Paratypes: 44 females (five with end-on view of head) on slides WT 1102 - 1125 .

Type habitat and locality: Sample 50. Found also in samples 59 and 60.

This species resembles P.subelongatus (Cobb, 1914) , from which it differs by the strongly protruding labial papillae, longer isthmus, plumper tail and absence of males. The structure of the posterior uterus of P. subelongatus is not known. From P.heterocheilus Steiner, 1935 , which species also possesses protruding labial papillae, P.papillosus differs by the lateral lips being not lower than the submedian ones, by the symmetrical uterus (in P.heterocheilus the anterior chamber is much longer than the posterior one), by the strongly protruding vulva lips and probably by less conspicuous body annulation.

Figures

FIG. 5. Panagrolaimuspapillosus n.sp.,female. A: neck region; B: vulva; C: tail.