Aporcelaimellus obscurus
(Thorne and Swanger 1953),
Heyns, 1965
                            Syn.:  Dorylaimus obscurus Thorne and Swanger, 1936
                              Eudorylaimus obscurus  (T. and S.) Andrassy, 1959
                              Aporcelaimus obscurus  (T. and S.), J. B. Goodey, 1961
Photo Gallery- Konza Prairie
Photo Gallery- Nine-mile Prairie
Photo Gallery- Haughton Crater

1.8-3.0 mm; a = 26; b = 4.0; c = 50-70; V = 50
2.1 mm; a = 33; b = 4.0; c = 60; T = 55

 Lip region angular, set off by deep constriction, its width about 1/3 that of neck base.  Amphids of large specimens frequently with stiffening element.   Spear about as long as lip region width, its aperture occupying about 1/2 its length. Esophagus enlarged by very gradual expansion near its middle, the dorsal gland well behind aperture.  Cardia bluntly conoid with disc-like anterior portion, usually slightly thicker on dorsal side.  Lateral field about 1/5 body width.  Vulva transverse with sclerotized labia.  Vagina extending 2/5 across body.  Ovaries reflexed about 1/2 their length.  Eggs varying from 1 to 3 body widths long but usually only slightly longer than body width. Tail dorsally arcuate to bluntly rounded terminus with conspicuous double layer of its cuticle, often with prominent radial striae.  Caudal papillae 2, arranged in tandem.  Males very rare and apparently not functional, although testes are filled with sperms, associated females have not been observed spermatized.
     Aporcelaimellus obscurus is distinct because of its relatively large size, angular lips, symmetrically bluntly rounded tail with conspicuous double layer of tail cuticle.
     Habitat:  Probably the most common species of DORYLAIMOIDEA in the Northern Great Plains, being present in almost every soil sample collected in any locality.  The variation in body length and egg size sometimes becomes confusing and may tempt the worker to establish several subspecies.  However, extensive collections show that the various morphological characters overlap until it is impossible to separate them.

DNA Sequences Obtained
Specimen: Collected:
KonzaI FF-53 Konza Prairie, First survey
KonzaI BB-35 Konza Prairie, First survey
KonzaI FF-140 Konza Prairie, First survey
KonzaII BC-39 Konza Prairie, First survey
SD SJ3-12 South Dakota bearberry
SD SJ3-02 South Dakota bearberry
TX1-06 Texas corn