A taxonomic review of the genus Goffartia Hirschmann, 1952 (Rhabditida: Diplogastridae) with a note on the relationship of congeners
Author
Tahseen, Qudsia
Author
Mustaqim, Malka
text
Zootaxa
2015
4034
1
journal volume
10.11646/zootaxa.4034.1.3
bec87bae-d212-4d40-8153-d5b102ac7c82
1175-5326
240726
0264F271-BB57-497A-94B8-F6B037F9D859
Goffartia heteroceri
Hirschmann, 1952
(
Figs. 1
C, 2B, 3C, 6)
Measurements.
Table 1,
Description.
Adult:
Body medium- to large-sized, between
0.7–1 mm
in length. Cuticle smooth under LM, without transverse and longitudinal striations. Lateral fields demarcated. Lip region low, rounded to dome-shaped; continuous with the adjoining body; lips fused; labial sensilla slightly raised. Amphidial apertures transversely oval, located at three-fourths of lip width from anterior end. Cheilostom long, cuticularised with diverging anterior and posterior ends; gymnostom and stegostom forming barrel-shaped buccal cavity; gymnostom arched; metastegostom without tooth; a single stomal ring partially proximally inserted into the pharynx. Pharyngeal collar almost one-fourth of stoma length, dorsally extending slightly into pharynx. Pharyngeal corpus muscular, median bulb strongly developed with ‘almond-shaped’ valve plates; anterior pharyngeal part equal to or longer than posterior part; basal bulb oval in shape, well demarcated from isthmus. Nerve ring not shown in the original illustration; secretory-excretory pore not discernible. Tail very long, narrowing into hair-like terminal part.
Female:
Reproductive system didelphic, amphidelphic with both genital branches symmetrical and largely equal. Vulva pre-equatorial. Uteri occasionally with a pair of eggs.
Male:
Similar to female in other morphological characters except being smaller. Reproductive system monorchic with a reflexed testis. Tail divided into an anterior conical part and an abruptly narrowing cylindrical part terminating in a whip. Genital papillae 9 pairs with two precloacal and seven postcloacal pairs with a configuration
of
v1
+
v2
/
v3
d,
v4
,ad, (
v5
+
v6
,
v7
), pd
. The genital pairs
v1
+
v2
are relatively close, subventral;
v3
d
at the level of cloaca, lateroventral;
v4
subventral;
ad
lateral;
v5
and
v6
subventral closer than
v7
;
pd
subdorsal. Phasmids located between
ad
and
v5
.
Spicules strong, falcate, about as long as cloacal body diameter, gubernaculum strong, trough-shaped with attenuated proximal end; about 40% of the spicule length. Tail long, filiform narrowing into hair-like terminal part.
Locality and habitat.
Goffartia heteroceri
has been reported from thermal spring (
Meyl 1953
,
1954
) and potable water (
Zullini 1981
,
1982
;
Volterra
et al.
1999
; associated with
Heterocerus
Fabricius, 1792
beetles in littoral habitats. The species has been found in Europe (
Germany
,
Hungary
,
Lithuania
) and is widespread in
Italy
, especially in the central regions of the peninsula (
Zullini,1982
).
G. heteroceri
lives phoretically on the heterocerid water beetles
Heterocerus fenestratus
Thunberg, 1784
,
H. fusculus
Kiesenwetter, 1843
and
H. marginatus
Fabricius, 1787
and also colonizes
Stenolophus teutonus
Schrank, 1781
(Carabidae)
and
Paederus riparius
Linnaeus, 1758
(Staphylinidae)
. The species is transported by the insect host to new aquatic habitats as the diapausing larvae overwinter in the host body between the folds of abdominal segments (
Steffan 1967
).
Salient characters.
The species is characterised by smooth cuticle without transverse and longitudinal striations; lateral fields demarcated; lip region low, rounded to dome-shaped; labial sensilla slightly raised. Amphidial apertures transversely oval, about one-fourth of the corresponding body diameter, or about stoma width; stoma barrel-shaped, unarmed with single ring; pharyngeal corpus having thick lumen and strongly built median bulb; anterior pharyngeal part equal to or longer than posterior part; both genital branches of female gonad almost equal; males with cephalated, arcuate and falcate spicules; gubernaculum 40–50% of the spicule length, troughshaped with tapering proximal and distal ends and genital papillae
v5
and
v6
closely placed and slightly distant from
v7
.