Photo Gallery-Homestead Nat'l Mon. |
Description (from Thorne, 1939)
Cuticle marked by radial striae which are especially
prominent on the tail. Lip
region discoid, set off by deep constriction, more than three times
as wide as high, and half as wide as base of neck. Six thick lip
flaps arched over vestibule. Amphids roughly triangular with apertures
about one-third head width. Sensilla elements four, arranged fan-like.
Lateral cords about one-fourth the body width with coarse granules so densely
packed as to obscure all traces of cells. Lateral pores arranged
in two lines. Pharynx about one-third head width. Encircling
the lower portion of pharynx is a flexible muscular element which generally
stands out distinctly from the wall proper. Guiding
ring double. Spear
about
as long as, and one-sixth as wide as lip region, the aperture occupying
almost one-half its length. Anterior portion of esophagus
one-fourth
to one-third as wide as neck, narrowing slightly at nerve ring. Posterior
three-fifths of esophagus enlarged by gradual expansion until about half
neck width. In some specimens there is little difference in width
of the two portions of the esophagus at their junction. Five esophageal
glands easily visible with perhaps an obscure sixth one opposite the dorsal
gland. Cardia
unusually elongated, from one to one and one-half times as long as the
body width. Walls of intestine two or three times as thick as adjacent
body cuticle, its cells obscure and packed with rather colorless granules.
Female prerectum length two or three times body width; rectum length about
twice anal body diameter. Vagina heavily cuticularized, extending
half way across body. Ovaries reflexed about half way to vulva.
Female tail hemispherical. Posterior
portion of male arcuate. Supplements
20-27,
the series beginning slightly anterior to the spicula. Submedian
papillae 6-8 pairs. Caudal papillae 6-8 pairs. Spicula dorylaimoid,
distal ends slightly bent forward. Lateral guiding pieces acute,
slender, V-shaped. Male prerectum variable in length but generally
just within range of anterior supplements; in one male from Virginia the
prerectum reached midway of the 20 supplements.
Diagnosis: Labronema with the above
measurements and general description. Distinguished from its most
closely related species, L. varicaudatum, and others by the broadly
discoid lip region.
A predacious species. Intestines contained
setae of oligochaetes. One specimen contained what apparently was
green algae or moss which may have been swallowed while catching living
prey.
Habitat: Soil about roots of cotton seedlings,
Florence, S. C.; pine tree nursery, Kirbyville, Texas; daffodil bulbs,
Texas (locality unknown); native plants, stream bank, Broad Run, Virginia.
All points in U. S. A.
DNA Sequences Obtained
Specimen: | Collected: |
SH-01 | Homestead National Monument, Beatrice NE |
9mi 4-30 LP2-10 | 9 Mile Prairie, First Survey |