Summary -Namaquanema hanki n. gen., n. sp. is described from South Africa. The new genus, which is placed in the Dorylaimidae, is distinguished by an amalgamated Iip region; a stylet without sclerotized odontophore but with short hooked processes at the base of the odontostyle; guiding ring double; ta il short in both sexes, dimorphic in type species; female didelphic, with longirudinal vulva sunken deep below body surface; male with numerous contiguous ventromedian supplements and long prerecrum. Résumé -Namaquanema hanki n. gen., n. sp. provenant d&apos;Afrique du Sud (Nematoda : Dorylaimoidea) -Description est donnée de Namaquanema hanki n. gen., n. sp. provenant d&apos;Afrique du Sud. Ce nouveau genre, placé dans les Dorylaimidae, se caractérise par une région labiale compacte, un stylet sans odontophore maIs pourvu de procès en fonne de crochet à la base de l&apos;odontostyle, un guide du stylet à double anneau, une queue courte chez les deux sexes, et dimorphique chez l&apos;espéce type, une femelle didelphique présentant une vulve en fente longirudinale profondément enfoncée en-dessous de la surface du corps, un mâle pourvu de nombreux suppléments ventro-médians contigus et un long prérecrum

Antoinette Swart

Juan Heyns

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Fundam. appl. NemalOl., 1993,16 (2),171-175
Namaquanema hanki n. gen., n. sp. from South Africa
(Nematoda : Dorylaimoidea)
Juan HEYNS and Antoinette SWART
Department of Zoology, Rand Afrikaans University, P. 0. Box 524,
Johannesburg, 2000, South Africa.
Accepted for publication 6 August 1992.
Summary - Namaquanema hanki n. gen., n. sp. is described from South Africa. The new genus, which is placed in the
Dorylaimidae, is distinguished by an amalgamated Iip region; a stylet without sclerotized odontophore but with short hooked
processes at the base of the odontostyle; guiding ring double; ta il short in both sexes, dimorphic in type species; female didelphic,
with longirudinal vulva sunken deep below body surface; male with numerous contiguous ventromedian supplements and long
prerecrum.
Résumé - Namaquanema hanki n. gen., n. sp. provenant d'Afrique du Sud (Nematoda : Dorylaimoidea) - Description
est donnée de Namaquanema hanki n. gen., n. sp. provenant d'Afrique du Sud. Ce nouveau genre, placé dans les Dorylaimidae, se
caractérise par une région labiale compacte, un stylet sans odontophore maIs pourvu de procès en fonne de crochet à la base de
l'odontostyle, un guide du stylet à double anneau, une queue courte chez les deux sexes, et dimorphique chez l'espéce type, une
femelle didelphique présentant une vulve en fente longirudinale profondément enfoncée en-dessous de la surface du corps, un mâle
pourvu de nombreux suppléments ventro-médians contigus et un long prérecrum.
Key-words: Nemata, Dorylaimidae, Namaquanema.
During a survey in Namaqualand in the north-west-
ern Cape Province eight specimens were found of a new
dorylaim species which do not fit any known genus.
Namaquanema hanki n. gen., n. sp. is therefore proposed
for the receipt of these specimens.
For SEM study, glycerine-moumed nematodes were
slowly hydrated ta distilled water and fixed in 1 % osmi-
um tetroxide (OS04). They were critical point dried,
sputter coated with gold (30 nm) and viewed with an
ISI SS 60 electron microscope at 10 kV.
Narnaquanerna n. gen.
DtAGNOSIS
Dorylaimidae. Medium-sized dorylaim with amalga-
mated lip region, axial stylet of moderate length with
hooked basal processes but without scJerotized odon-
tophore, basal bulb somewhat more than· half neck
length, double guiding ring, tail dimorphic in type spe-
cies, convex-conoid with dorsally directed fingerlike
process in female, convex-conoid bluntly rounded in
male. Vulva longitudinal, sunken deep below body sur-
face. Didelphic, amphidelphic. Male diorchic with dory-
laimoid spicules and lateral guiding pieces. Ventrome-
dian supplements numerous, contiguous. Prerectum
short in female, long in male, extending well beyond the
supplements.
TYPE AND ONLY SPECIES
Namaquanema hankz· n. gen., n. sp.
RELATIONSHIPS
On the basis of tail shape alone, this species could
equally well have been placed among either the long-
tailed dorylaims (Dorylaimidae) or short-tailed dory-
laims (Qudsianematidae). Similar short, dimorphic tails
are found for example in some Mesodorylaimus species,
such as M. aduncus Andrâssy, 1986, M. procerus An-
drâssy, 1986 and M. recurvus Andrâssy, 1964, as weil as
in Laimydorus, e.g. L. centrocercus (de Man, 1880), and
it also occurs in Coomansinema dimorphicauda Ah-
mad & ]airajpuri, 1989, a species which its describers
placed in the Thornenematidae. On the other hand, an
almost similar dimorphic condition is seen in a few La-
bronema species, e.g. L. digitatum Sukul, Das & Mitra,
1975 and L. vancaudalum (Thorne, 1929). Superficial-
Iy our species does in fact remind of a Labronema. There
are, however, very profound differences, viz. absence of
Iip flaps, amalgamated lip region and most remarkable,
absence of a scJerotized odomophore. On the basis of
the lip region alone one could consider Willinema, a
genus of the fa mily Thorniidae, but this genus is opis-
thodelphic. Also to be considered is Labronemella, but
here again the lip region is totally differem, described as
discolaimoid by Andrâssy (1985). Identification of our
new species with Andrâssy's (1976) key to Dorylaimoi-
dea (p. 209) leads to item 4 where the choice is between
item 5 (= Dorylaimoididae) and item 6. Although our
species fits neither alternative, the more logica1 choice
seems to be item 6. The next choice then is between 7
ISSN 1164-5571/93/02/l71 05 $ 2.50/ © Gauthier-Villars - ORSTOM 171
J. Heyns & A. Swan
(tails of both sexes short, maximum three times anal
body diameter) vs 12 (at least female taillonger than five
times anal body diameter, if shorter, then with sexual
dimorphism). Here item 7 seems to be the more logical
choice, and this then leads on to item Il (= Qudsiane-
matidae). If the other alternative (item 12) is taken, this
leads to 15 (= Dorylairnidae), where (on page 210) it
eventually leads ta item 3 (= Lairnydorinae).
At least one species presently placed in Laimydorus
has a similar short dimorphic tail, viz. L. centrocercus (de
Man, 1880), which was placed in Eudorylaimus by An-
drassy (1959), in Mesodorylaimus by Geraert (1966) as
well as by Khera (1970), but which Siddiqi (1969),
correctly in our opinion, transferred to his new genus
Laimydorus. This species also has a double guiding ring,
long prerectum in the male, and numerous contiguous
ventromedian supplements.
The position of oesophageal gland nuc1ei and their
openings also has to be considered in establishing the
relationship of the new genus. Both DO and DN are
further anterior (at 44-48 % and 46-50 % respectively)
in our genus than in most Mesodorylaimus species (cf.
Loof & Coomans, 1970). Naturally Loof and Coomans
(1970) did not consider Laimydorus, since this genus
had not been established at the time of their study, but
presumably the situation here is on the whole similar to
that in Mesodorylaimus. The ~ame difference exists be-
tween our genus and Labronema, except for L. ferox
Thome, 1939, for which Loof and Coomans (1970) cite
DO and DN ar 40 % and 43 % respectively.
From the foregoing discussion it is c1ear that our spe-
cies does not fit any existing genus in either the Qud-
sianematidae or Dorylaimidae, and therefore we pro-
pose the new genus Namaquanema for its reception. It
seems to come c10sest ta Laimydorus, and is thus provi-
sionally regarded as belonging to the Lairnydorinae.
Namaquanerna hanki* n. sp.
(Figs 1-3)
MEASUREMENTS
Female (n = 4, holotype and three paratypes) : L =
2.91 (2.70-3.06) mm; a = 40.3 (37-42); b = 5.0 (4.6-
5.4); c = 68 (64-73); c' = 0.98 (0.90-1.08); V = 48.9
(47.6-49.9) .
Paratype males (n = 4) : L = 3.12 (2.89-3.33) mm;
a = 44.5 (43-46); b = 5.4 (5.2-5.5); c = 108 (100-116);
c' = 0.78 (0.71-0.86).
Holotype (female) : L = 3.06 mm; a = 42; b = 5.4; c =
73; c' =0.90; V =49.3.
* This species is named after Professor Hank Swanepoel, Chair-
man of the Departrnent of Zoology, in recognition of his support
and encouragement over many years, as weil as his invaluable
help with translation of Russian papers.
172
DESCRIPTION
Adult: Heat relaxed body only slightly ventrally
curved, with only posterior end of male slightly more
strongly curved. Lips amalgamated; lip region 17.6 (17-
19) j..Lm wide, evenly rounded, but flattened anteriorly;
narrower than adjoining neck. Cuticle appears smooth
under LM, but fine transverse striae can be seen with
SEM; 6 j..Lm thick on anterior part of neck, 4.5-6 j..Lm at
midbody, and 10.5-13 j..Lm dorsally on female tail,
7-9 j..Lm on male tail. Cuticle appearing (under LM) to
consist of three main layers, with the thin outer layer of
equal thickness throughout, the two inner layers slightly
thickened towards both extremities. Anteriorly the divi-
sion between the two thick inner layers disappears at
about two lip region widths from the anterior end, and
posteriorly it disappears towards the middle of the tail.
Lateral body pores obscure, except on anterior part of
neck where a single lateral row can be seen, which di-
verges into two rows towards the middle of the neck.
Ventral body pores apparently present over entire length
of body, but distinct only in neck region. Under LM
several distinct midventral papillae can be see'1 on either
side of the vulva, but strangely enough these can not be
distinguished on the SEM photo. Two, three or four
indistinct dorsal pores can be seen on the anterior part of
the neck. Mouth opening small, hexangular, without
liplets or flaps. Odontostyle in both sexes 19.9 (19-
22) j..Lm long and 2-2.5 j..Lm broad; aperture 6-7 j..Lm
long. Odontostyle with the usual forked appearance bas-
ally (due ta the presence of a basal collar; see Swart
oped, reaching more than halfway across body. Uterus
sclerotized odontophore. In fact, the collar itself seems
to extend posteriorly to form a hooked process, especial-
Iy visible in a dorso-ventral view. Anterior part of lumen
of oesophagus (i.e. the part enc10sed by the weak pro-
bulbus, where odontophore occurs in most dorylaims),
thinwalled and irregularly twisted. Guiding ring double,
with the posterior, stronger ring situated 9.5-10.5 j..Lm
from anterior end. Amphid funnel-shaped, the aperture
9-10 j..Lm wide, i.e. slightly more than half the lip region
width, situated 6-7 j..Lm from the anterior end; posterior
edge of aperture appearing minutely serrated under LM
(but not seen with SEM). Anterior part of oesophagus
relatively broad, narrowing only slightly about three lip
region widths from anterior body end ta form a weak
probulbus. Basal bulb measured from beginning of ex-
pansion constituting about 60 % of neck length. Total
neck length (anterior body end ta posterior end of basal
bulb) 575 (547-611) j..Lm. Oesophageal gland nuc1ei and
their outlets mostly difficult ta discern, except S202 rath-
er prominent, situated 10.9 (9.9-11.9) j..Lm from base of
bulb. Position of nuclei and outlets as follows (n varies
from 2 to 6; DO, DN and SPl =6) : DO =44.2-48.4;
DN = 46.6-50.4; DO-DN = 1.7-2.4; SIOI = 67.8-70.6;
SIOl = 70.0-71.2; SI-NI and SINl = 67.4-68.9; SlOI =
86.3-87.2; S202 = 88.5-90.1; SlN I and S2N2 = 85.0-
Fundam. appl. Nematol.
Namaquanema hanki n. gen. n. sp.
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Fig. 1. Namaquanema hanki n. gen., n. sp. A: Anterior part of holorype female; B: Surface view of head of holotype; C :
Dorso-ventral view of head region; D: Anterior body region; E: Basal bulb of anoÙ1er specimen; F: Posterior branch of
reproductive system of holorype female; G, H : Vulval region in (WO pararypes.
Vol. 16, n° 2 - 1993 173
]. Heyns & A. Swan
jJ E F40 ~m .A-C
50 ~m ,D
33 ~m ,E,F
Fig. 2. Namaquanema hanki n. gen., n. sp. A : Tai! of holorype female; B, C : Tails of rwo pararype females; 0 : Posterior region of
male; E : Lateral guiding piece; F : Spicule.
87.6. Cardia hemispherica1. Prerectum 195-267 I-lm
long in female, i.e. four to five times corresponding body
diameter; longer in male, 360-410 I-lm, or six and a half
to seven and a half times body diameter, beginning weil
in front of the supplements. Rectum 41-49 I-lm long in
female, i.e. about equal to anal body diameter. Female
tau 42-44 I-lm long, almost hemispherical, but with a
conspicuous dorsally directed terminal fingerlike pro-
cess. Male tail bluntly rounded, 28.5-31 I-lm long.
Female: Vulva situated in a profoundly sunken, dia-
mond-shaped area. Vulva itself a short longitudinal slit.
Without vulval sclerotization. but vulva-vagina junction
surrounded by a stippled area. Vagina strongly devel-
oped, reaching more than halfway across body. Uterus
broad, without differentiated ovejector. Distal part of
uterus with a more strongly muscular area, Ieading to a
weakly differentiated pars dilmata. Sphincter between
uterus and oviduct. Pars dilatala oviduclUs apparently
differentiated into mo parts. Rest of oviduct with a se-
ries of about 30 discoid ceUs. Ovary reflexed with tip at
about level of sphincter. Two uterine eggs observed,
measuring 117 x 51 I-lm and 134 x 52 I-lm (egg shell in-
c1uded); egg sheIl4.5-7I-lm thick.
174
Male: Spicules typically dorylaimoid, strong, with
well-developed inner strengthening, the area between
the outer rim and inner strengthening with a sùppled
appearance; 65-70 I-lm long measured along the curved
median !ine. Lateral guiding pieces sigmoid, with the
distal end sharply pointed; 10-14 I-lm long. Supple-
ments consisting of an adanal pair and a series of thir-
teen to fifteen contiguous ventromedian ones, the series
beginning about one half body diameter anterior to the
spicules. Ali supplements situated on a midventral ridge
bordered by two deep grooves. In the SEM photo it
appears as if there could be a second pair of supple-
ments somewhat anterior to the adanal pair, but their
presence could not be confirmed under LM. Eight or
nine subventral papillae occur in the posterior region of
the male, while sorne laterovenrral pores are also visible,
both under LM and SEM. Testes two, opposed, out-
stretched. Mature sperm cells in testes ovoid, measuring
11-12 x 3.5-5 I-lm; sperm cells appearing more oblong
in uteri of female measuring 7-9 x 2-2.5 I-lm. Copulato-
ry muscles strong, extending for a short distance beyond
the anteriormost supplement. Ejaculatory glands (six?)
reaching beyond anteriormost supplement, but not as
far as prerectum-intestine junction.
Fundam. appl. Nemalol.
Namaquanema hanki n. gen. n. sp.
Fig. 3. Namaquanema hanki n. gen., n. sp. A : En-face view of female; B : Male rail; C : Female rail; D : Supplemenrs; E : VuIval area
(Bar equa/s 10 jJ.m).
TYPE LOCALITY AND HABITAT
Soil from the bank of a small stream in LangkJoof,
ben",een Garies and Wolfhoek in NamaquaJand, north-
western Cape Province, South Africa. Collected August
1987.
TYPE SPECLMENS
Holotype the left hand specimen on slide RAU 3531,
MO female paratypes on the same slide, and three male
pararypes on slide RAU 3532, in the collection of the
Department of Zoology, Rand Afrikaans University, Jo-
hannesburg.
References
ANORAssy, I. (1959). Taxonomische Übersicht der Dorylai-
men (Nemaroda), 1. Acta zoo/. hung., 5 : 191-240.
Vol. 16, n° 2 - 1993
ANORAssy, 1. (1976). Evo/Ulion as a basis for lhe sySlemaliza-
Lion of nemalodes. London, Pirman Publishing, 288 p.
ANORAssy, I. (1985). A dozen new nemarode species from
Hungary. Opusc. zoo/. BpeSl., 9-10: 3-39.
GERAERT, E. (1986). The systematic position of sorne Dory-
Iaimus-species. Biol. Jaarb., 34: 110- 121.
KHERA, S. (1970). Nematodes from me banks of stiU and
running waters. X. Order Dorylaimida. IndianJ. He/minth.,
22: 120-135.
SIDDIQI, M. R. (1976). iVlumtazium mumlazae n. gen., n. sp.
(Nemaroda: Tylencholaimidae) wim me proposaI of Lai-
mydorus n. gen. (Thornenematidae). NemaLO/ogica, 15:
234-240
SWART, A. & HEYNS, J. (1987). Morphological study oflongi-
dorid nematode stylets using me SEM. PhyLOphy/acLica, 19 :
103-106.
175


Namaquanema hanki n. gen., n. sp. from South Africa (Nematoda : Dorylaimoidea)

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Namaquanema hanki n. gen., n. sp. from South Africa (Nematoda : Dorylaimoidea)

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