Teratocephalus decarinus Anderson, 1969

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 : 31

Teratocephalus decarinus Anderson, 1969

( Fig. 6 , A -C)

Dimensions often females: L = 0. 52- 0.56 mm; a = 23 -24; b = 3.7 -3.9; c = 4.8 - 5.7; V = 1 3 _1 8 54 -5 8. First two annules behind lip region small and compressed; the next four to six are directed anteriad. Vulva depressed; a short postvulval sac is present. The tail measures 9-11 anal body diameters; vulva-anus distance is 138 -145 % of tail length.

Samples 62, 66 and 67.

The distinction between this species and T.costatus Andrässy, 1958 is somewhat problematical. A population from New Galloway, Scotland, is clearly T. costatus because of the shape of the neck annules, but the cervical expansion characteristic of that species is absent, as in T. decarinus . Specimens from the island of Terschelling, The Netherlands, have the characters of T. decarinus , but a juvenile has the neck annules shaped as in T. costatus . Clear differences in tail tip and shape of body annules could not be found between all these populations. So for the moment the only established difference is the shape of the neck annules: directed anteriad in decarinus , not so in costatus . Whether this difference is really of specific importance remains to be seen. T. decarinus is now known from northern Canada, Spitzbergen, Sweden (Flommen) and Scotland; T.costatus from Bulgaria and the Netherlands. The species has also been reported from Paraguay (Andrässy, 1968).

Figures

FIG. 6. A-C: Teratocephalus decarinus Anderson,female.A:neck region; B: gonad; C: tail. D-E T. terrestris (Bütschli), female. D: neck region; E: tail. F: T.lirellus Anderson, female, entire specimen.