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