GEN.CHAR. Body tapering at extremities. Caudal
sucker none. Integument having longitudinal as well as transverse
striae; setae none; papillae none. Pharyngeal cavity
long cylindrical. Esophagus distinctly muscular, having two
swellings, one elongated near its middle, and the other terminal, rounded,
and containing a simple valvular apparatus. Intestine rather sparsely
covered with fat-particles, the large containing cells of which can sometimes
be recognized. Vulva near the middle of body. Uterus
bifid, segments symmetrical. Oviparous or vivparous.
Spicules of moderate size, slightly curved. Accessory piece
single,
posterior, median, about half as long. Caudal alae
lateral, membranous,
supported by sets of rays. Ventral gland wanting. Lateral vessels
or cellular canals not seen. Movements active.
Although I have looked very carefully for them, I have been unable
to distinguish either lateral vessels or the ventral excretory gland in
any of the representatives of this genus.
The typical Rhabditis terricola of Dujardin seems undoubtedly
to correspond as regards structural details wth the other species that
I have placed in this genus; and, since it is now evident that Dujardin
associated with this animal others of such diverse types as Anguillula
aceti and Tylelenchus tritici, we shall have the less difficulty
in imagining that he may have confounded with them also members of the
genus Plectus, not only because they seem to be much more abundant
than are the proper representatives of the genus Rhabditis, but
also because he speaks of the latter as possessing that remarkable tenacity
of life which belongs to species of the two former genera, when , as far
as my exp[erience goes, it is not possessed by th real allies of the typical
Rhabditis
terricola.
(Description- Bastian, 1865)
Definition: Rhabditinae. Lips closed, not forming an open
cup. Oesophageal collar always present. Metarhabdions with
5 or 3 tubercules in place of teeth, often anisoglottid, sometimes anisomorphic.
Vulva median, ovaries paired, oppposed reflexed. Female tail of various
shapes. Male tail usually leptoderan, peloderan in one subgenus.
Spicules separate.
Bionomics. All species occur where bacteria are plentiful, on
which they feed. Hirschmann (1952) showed that breeding of Rhabditids
depends on ingestion of living bacteria.
(Description- Goodey, 1963)
