Bakernema inaequale
(Taylor, 1936) Mehta & Raski, 1971

Photo Galleries:
Great Smoky Mountains National Park

Pachaug State Forest, Connecticut
Grundy State Forest, Tennessee


Length, .56 mm; a = 7.  Body tapering toward head, tail somewhat rounded.  Head composed of two spine-bearing annules, set off by a constriction and supported internally by a six-branched framework of brownish cuticular substance.  Annules 64-70, 8-9 um wide, some anatomosing.  Spines scale-like, mostly wider than long, retrorse, transparent, wedge-shaped in longitudinal section, irregular in size and shapep but nearly equal in length.  Twelve to 16 spines to each annule, not in definite longitudinal rows.   Spines on ventral side of two annules in front of vulva missing or seeminly modified to form a scale covering the vulva.  Terminus of tail a transparent knob.  Oesophagus swollen by stylet muscles in front of the ellipsoidal middle bulb.  Latter 1/2, isthmus 1/5, terminal bulb 1/4 neck width.  Stylet straight, stout, length 70 um, or 13% of body length, extending through 8-9 annules.  Basal knobs of stylet large, rest at anterior portion of middle oesophageal bulb.  Nerve ring oblique.  Anterior end of intestine partially surrounding terminal oesophageal bulb.  Anus at 5th annule in front of terminus; vulva at modified 6th annule in front of terminus.  Vagina in lateral view seemingly extending forward one annule, then inward and forward 1/3 body width. Uterus extending forward 1 1/2 times body width, half as wide as body.  Ovary straight, proximal portion 1/2 body width, tapering to 1/5 body width and expanding slightly at blind end, which is located opposite center of middle oesophageal bulb.  Egg (apparently full grown) 40 um X 70 um.  Excretory pore between 8th and 9th annules.  Male unknown, none among 50 specimens.
    Habitat:  Leaf mould from woods south of Alexandria, Virginia, U.S.A.
(Description- Taylor, 1936)

Measurements (22 females):  L = 531 um (471-599); stylet = 64 um (60-67); V = 94.30% (92.6 - 95.6); Rv = 6 (4-7); R = 67 (61-72); Rex = 20 (18-22); Ran = 3.
Associated plants and localities:  Soil around roots of Acer saccharum Marsh., near parking lot to Raven Trail, north of Lake Tomahawk, Wis.; grass beneath Pinus strobus L. in the American Legion State Park, Wis.; Abies balsamea (L.) Mill. near parking lot west of Blue Mt. Lake, NY.; A. saccharum and Betula papyrifera var. cordifolia (Regel) Fern. on the Daniel Webster Trail, near Dolly Copp Campgrounds, Gorham, N.H.
    This species was first described by Taylor (1936).  It was later mistakenly described as a new species (Wu, 1964), but the error was corrected by Mehta and Raski (1971).
    The specimens from Wisconsin, New Hampshire, and New York resemble one another closely, and, except for the location of the excretory pore, fit previous descriptions.  The descriptions of Taylor (1936) and Golden and Friedman (1964) locate the excretory pore on the 8th to 9th annule from the anterior end.  My observations and those of Wu (1964) and Mehta and Raski (1971) found it on the 18th to 22nd annule from the anterior end.
    This species is most easily recognized in having no offset head annules, a membranous cuticular fringe, a short stylet, and in the manner by which the anterior vulval flap projects posteriad displacing the following annule slightly.
    Males of this species were found occasionally and conform to their description made by Wu (1964) except that no anal sheath was observed.
(Description- Hoffman, 1974)

This species  included in the Criconematid Project