European Journal of Taxonomy 63: 1-32
http://dx.doi.org/10.5852/ejt.2013.63
BY
This work is licensed under a Creative Commons Attribution 3.0 License.
ISSN 2118-9773
www. europeanj ournaloftaxonomv. eu
2013 • Leduc D.
Research article
urn:lsid:zoobank.org:pub:BB33641C-6FAF-4D2E-93FB-C4951F7C058C
Two new genera and five new species of Selachinematidae (Nematoda,
Chromadorida) from the continental slope of New Zealand
Daniel LEDUC
National Institute of Water and Atmospheric Research (NIWA), Private Bag 14-901, Kilbimie,
Wellington, New Zealand
E-mail: [email protected]
um:lsid:zoobank.org:author:9393949F-3426-4EE2-8BDE-DEFFACE3D9BC
Abstract. Two new genera and five new species of Selachinematidae are described from the New Zealand
upper continental slope (350-1240 m depth). Synonchiella rotundicauda sp. nov. is characterised by
cephalic setae 0.25 cbd long, mandibles each with two pairs of hooks and two wing-like projections
laterally, eight cup-shaped pre-cloacal supplements and short rounded tail. Pseudocheironchus gen. nov.
is similar to Cheironchus , but differs from the latter in having a cuticle without lateral differentiation,
cephalic setae only slightly longer than the outer labial sensillae, and a posterior buccal cavity with three
equal mandibles. Pseudocheironchus ingluviosus gen. et sp. nov. is characterised by mandibles with
eight blunt teeth, multispiral amphideal fovea with five turns, and a short rounded tail. Males of this new
species with 17-19 cup-shaped pre-cloacal supplements. Males of the genus Cobbionema are described
for the first time; C. trigamma sp. nov. is characterised by four long cephalic setae and six smaller
outer labial setae in one circle, six rhabdions surrounding the anterior buccal cavity, each with two
pairs of pointed projections at their posterior extremities, posterior buccal cavity widening posteriorly,
with three pairs of rhabdions fused posteriorly and widening anteriorly, males with two testes pointing
anteriorly and with reflexed posterior testis, and no pre-cloacal supplements. Gammanema agglutinans
sp. nov. is characterised by a short, stout body often covered in adhering mucus and detritus, cuticle with
minute spines, leaf-shaped somatic setae with ducts, sexual dimorphism in the shape of the amphideal
fovea (loop-shaped in males and spiral in females), posterior buccal cavity with three pairs of broad,
column-shaped rhabdions fused anteriorly, intestine cells with orange-brown granules, and small tubular
pre-cloacal supplements. Bendiella gen. nov. is most similar to Halichoanolaimns , but differs from the
latter, and all other genera of the family Selachinematidae, in having a cuticle with lateral differentiation
consisting of longitudinal rows of larger dots, and from all other genera of the Choniolaiminae in lacking
pre-cloacal supplements. Bendiella thalassa gen. et sp. nov. is characterised by amphideal fovea with
5.25 turns, anterior buccal cavity with twelve rhabdions, each with a pair of pointed projections at
posterior extremity, posterior buccal cavity with three Y-shaped pairs of slender rhabdions fused from
two thirds of distance from anterior ends, and conico-cylindrical tail.
Key words. Selachinematinae, Choniolaiminae, marine predatory nematodes, bathyal. Southwest
Pacific.
Leduc D. 2013. Two new genera and five new species of Selachinematidae (Nematoda, Chromadorida) from the
continental slope of New Zealand. European Journal of Taxonomy 63: 1-32. http://dx.doi.org/10.5852/eit.2013.63
1
European Journal of Taxonomy 63 : 1-32 ( 2013 )
Introduction
The family Selachinematidae Cobb, 1915 is a group of predatory nematodes widespread in the world’s
oceans (e.g., Jensen 1987; Pereira et al. 2009). The taxonomy of the group was revised in detail by
Gerlach (1964). A key to the genus Synonchiella Cobb, 1933 was provided by Fadeeva (1988), and,
more recently, Tchesunov & Okhloplcov (2006) reviewed and described some selachinematid specimens
from the Northeast Atlantic and provided an emended diagnosis for the genus Cheironchus Cobb, 1917.
Selachinematids are most often reported from relatively coarse sediments in shallow water environments
(e.g., Warwick 1971; Okhloplcov 2002; Tchesunov & Okhloplcov 2006). They also occur in deep-sea
habitats, with eight species belonging to three genera recorded from water depths >400 m worldwide
(Miljutin et al. 2010).
Only two species of Selachinematidae are presently known from the New Zealand Exclusive Economic
Zone, viz., Halichoanolaimus oval is Ditlevsen, 1921 and H. robustus (Bastian, 1865) (Leduc & Gwyther
2008). Here, two new genera and five new species of Selachinematidae are described from the continental
slope of New Zealand (350-1240 m depth).
Material and Methods
Sediment samples were obtained from the Chatham Rise and Challenger Plateau, two major bathymetric
features of the continental slope of New Zealand. Details of the study region and sampling sites are
given in Leduc et al. (2012a, 2012b). Briefly, samples were collected along a transect at 178°30' E
across the Chatham Rise (nine sites, 350-3100 m depth) in austral spring (September-October) 2001
during National Institute of Water and Atmospheric Research (NIWA) cruise TAN0116. Twenty-three
additional sites between 240 and 1300 m depths on the Chatham Rise and Challenger Plateau were
sampled in austral autumn-early winter (March-April and May-June) 2007 (NIWA cruises TAN0705 and
TAN0707, respectively). Additional samples were obtained in February 2011 (NIWA cruise TAN1103)
from a site near the middle of Chatham Rise crest at 350 m depth, and in November 2011 (NIWA cruise
TAN 1116) from a site on the northern flank of Chatham Rise at 470 m depth.
Sediment samples were collected using an Ocean Instruments MC-800A multicorer (core internal
diameter = 9.5 cm). Each sample consisted of one subcore of internal diameter 26 mm taken to a
depth of 5 cm. Samples were fixed in 10% formalin and stained with Rose Bengal. Samples were
subsequently rinsed on a 1 mm sieve to remove large particles and on a 45 pm sieve to retain nematodes.
Nematodes were extracted from the remaining sediments by Ludox flotation and transferred to pure
glycerol (Somerfield & Warwick 1996). Species descriptions were made from glycerol mounts using
differential interference contrast microscopy and drawings were made with the aid of a camera lucida.
All measurements are in pm, and all curved structures are measured along the arc. Type specimens are
held in the NIWA Invertebrate Collection (NIC), Wellington. Abbreviations in the text are as follows:
a =
body length/maximum body diameter
abd =
anal body diameter
b
body length/pharynx length
c =
body length/tail length
cbd =
corresponding body diameter
L
body length
n =
number of specimens
%V
vulva distance from anterior end of body x 100/total body length
2
LEDUC D., Selachinematidae from the continental slope of New Zealand
Results
Class Chromadorea Inglis, 1983
Subclass Chromadoria Pearse, 1942
Order Chromadorida Chitwood, 1933
Suborder ChromadorinaFilipjev, 1929
Superfamily Chromadoroidea Filipj ev, 1917
Family Selachinematidae Cobb, 1915
Diagnosis
(Modified from Decraemer & Smol 2006.) Body usually stout. Cuticle punctated with or without
lateral differentiation. Head sensillae may be jointed. Amphideal fovea usually multispiral, rarely loop¬
shaped. Buccal cavity spacious, divided into two compartments, either reinforced by cuticularised
rhabdions in both portions (Choniolaiminae), or with posterior rhabdions modified into protrusible
mandibles (Selachinematinae). Pharynx with or without posterior bulb, anterior bulb sometimes present
('Cheironchus and Pseudocheironchus gen. nov.). Males usually with two outstretched testes, either on
same or different sides of the intestine; pre-cloacal supplements usually present, usually cup-shaped,
sometimes setose, papillifonn, rarely tubular. Female didelphic-amphidelphic with reflexed ovaries.
Remarks
The holophyly of the family Selachinematidae is based on the holapomorphy of a spacious buccal
cavity without teeth or, if teeth are present, they are not homologous with teeth found in other
Chromadorida (Forenzen 1981).The family placement of Richtersia Steiner, 1916 and Desmotersia
Neira & Decraemer, 2009 remains uncertain and these genera are considered by some as intermediate
between the Selachinematidae and Desmodoroidea (e.g., Pastor de Ward & Fo Russo 2007; Neira &
Decraemer 2009). The genus Dignathonema Filipjev, 1918 was synonymised with Cheironchus Cobb,
1917 by Filipjev (1926). Trogolaimus Cobb, 1920 was classified in the subfamily Selachinematinae by
Gerlach (1964), but, as Tchesunov & Okhlopkov (2006) noted, this genus should be assigned to the
Choniolaiminae based on the structure of the buccal cavity. The latter authors considered Trogolaimus
to be a synonym of Gammanema Cobb, 1920. Nunema Cobb, 1933 and Pteronium Cobb, 1933 were
considered doubtful by Hope & Murphy (1972).
Subfamily Selachinematinae Cobb, 1915
Diagnosis
Anterior portion of buccal cavity reduced, posterior portion with three denticulate mandibles (modified
rhabdions); dorsal mandible may be reduced.
Valid genera
Cheironchus C obb, 1917
Demonema Cobb, 1894
Kosswigonema Gerlach, 1964
Synonchiella Cobb, 1933
Synonchium Cobb, 1920
Genus Synonchiella Cobb, 1933
Type species
Synonchiella truncata Cobb, 1933
3
European Journal of Taxonomy 63 : 1-32 ( 2013 )
Diagnosis
Cuticle without lateral differentiation. Outer labial setae and cephalic setae usually in one circle. Buccal
cavity with three equal mandibles made of two branches fused posteriorly; the two branches completely
fused in some species (e.g., S. rotundicauda sp. nov.). Pharynx without posterior or anterior bulb. Cup¬
shaped pre-cloacal supplements present.
Remarks
Synonchiella denticulata Cobb, 1933, S.feroxC obb, 1933 and S. siphonolaimoides (Allgen, 1940) were
considered doubtful by Gerlach (1964) due to incomplete descriptions. The latter author also transferred
S. annulata Gerlach, 1952 and S. orcina Gerlach, 1952 to the genus Latronema.
Valid species
S. dilarae Fadeeva, 1988
S. edax Aissa & Vitiello, 1970
S. forceps (Gerlach, 1957)
S. hopperi Ott, 1972
S. japonica Fadeeva, 1988
S. lutosa Gagarin & Klerman, 2007
S. major Murphy, 1965
S. micramphis (Schuurmans-Stekhoven, 1950)
S. microspiculoides (Schuurmans-Stekhoven, 1946)
S. minor Murphy, 1965
S. minuta Vitiello, 1970
S. riemanni Warwick, 1970
S. roscoffiensis De Coninck, 1965
S. siphonolaimoides (Allgen, 1940)
S. spiculora Murphy, 1962
S. truncata Cobb, 1933
Synonchiella rotundicauda sp. nov.
Figs 1-3, Table 1
urn:lsid:zoobank.org:act:2145BDA7-84F7-4DF4-A401-7B706F0C0088
Diagnosis
Synonchiella rotundicauda sp. nov. is characterised by cephalic setae 0.25 cbd long, mandibles each
with two pairs of hooks and two wing-like projections laterally, multispiral amphideal fovea with 3.5
turns, eight cup-shaped pre-cloacal supplements, and short tail (2.2. abd) with rounded extremity.
Etymology
The species name is derived from the Tatin rotundus (= round, circular) and cauda (= tail), referring to
the unusual rounded shape of the tail.
Material examined
Holotype
NEW ZEALAND: $, NIWA 88354,17 Apr. 2007, NIWA cruise TAN0705, station 172, eastern Chatham
Rise crest, 43.5162° S, 178.6167° W, 422 m, fine sand (53.5%), silt/clay (23.5%), very fine sand (18.9%).
Paratype
NEW ZEALAND: 1 $,NIWA88355, 15 Nov. 2011, NIWA cruise TAN1116, station 107, northern flank
of Chatham Rise, 42.8625° S, 177.9253° E, 467 m.
4
LEDUC D., Selachinematidae from the continental slope of New Zealand
Fig. 1 . Synonchiella rotundicauda sp. nov. A. Anterior body region of female. B. Male head. C. Surface
view of male head. D. Surface view of female head. E. Male posterior body region. F. Female posterior
body region. G. Mandibles, en face (left) and lateral (right) views. H. Spicule and gubernaculum. Arrow
shows position of duct connecting anterior end of marginal tube and buccal cavity. Scale bar: A, E-F =
25 pm; B-D = 15 pm; G = 8 pm; H =13 pm.
5
European Journal of Taxonomy 63: 1-32 (2013)
Description
Male
Body cylindrical, tapering slightly towards anterior extremity. Cuticle ~ 2.0 pm thick throughout body,
thicker in tail region, 4 pm, with transverse rows of punctations, without lateral differentiation. Somatic
setae short and sparse, in four sublateral rows. Head blunt, rounded, not set off. Six conical inner labial
papillae, ~1.5 pm long; six longer outer labial setae, 4 pm long, and four cephalic setae, - 1 pm long,
situated close to or slightly anteriorly to outer labial setae (Fig. 1C). Amphideal fovea cuticularised,
multispiral, 3.5 turns. Anterior portion of buccal cavity short and narrow, with inconspicuous rhabdions
at anterior extremity. Posterior buccal cavity with three equal mandibles, 15 pm long, with one mandible
situated dorsally and two sub-ventrally; each mandible with two pairs of hooks at anterior extremity and
two larger wing-like projections emerging laterally and pointing anteriorly; mandible also with small
duct apparently connecting anterior extremity of marginal tubes and opening into buccal cavity near
anterior end of mandible (Fig. 1G). Posterior buccal cavity surrounded by slightly swollen pharyngeal
A
Fig. 2. Synonchiella rotundicauda sp. nov. A. Entire male. B. Female reproductive system. Scale bar:
A = 150 pm; B = 75 pm.
6
LEDUC D., Selachinematidae from the continental slope of New Zealand
tissue, pharynx widening posteriorly, not forming true bulb. Several light refractive, golden-brown
corpuscules present in pharyngeal region (also present in tail; Fig. 3A, B). Nerve ring at 45% of pharynx
length from anterior end. Secretory-excretory (S-E) system present, cellular body of ventral gland small,
situated immediatly posterior to pharynx, pore situated ~0.5 cbd posterior to nerve ring.
Fig. 3. Synonchiella rotundicauda sp. nov. Light micrographs. A. Anterior body region of male showing
buccal cavity. B. Tail of male. C. Spicular apparatus. Scale bar = 25 pm.
7
Table 1. Morphometries (pm) of Synonchiella rotundicauda sp. nov. and Pseudocheironchus ingluviosus gen. et sp. nov. — a = body length/
maximum body diameter; abd = anal body diameter; b = body length/pharynx length; c = body length/tail length; cbd = corresponding body
diameter; L = body length; n = number of specimens; V = vulva distance from anterior end of body; %V = V/total body length.
European Journal of Taxonomy 63: 1-32 (2013)
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LEDUC D., Selachinematidae from the continental slope of New Zealand
Reproductive system diorchic with outsretched testes. Both anterior and posterior testes on right of
intestine. Oval-shaped, nucleated sperm cells, ~ 6 x 7 pm. Spicules paired, strongly curved, 1.8 abd
long, widest in middle portion and tapering distally; thin cuticular projection extending from proximal
end over almost half of spicule length. Gubernaculum small, plate-like, without lateral pieces, parallel
to distal end of spicules. Mid-ventral row of eight cup-shaped pre-cloacal supplements, ~ 4 pm wide
and 4 pm deep, situated 6-8 pm apart; distance between supplements increasing slightly anteriorly.
Pre-cloacal supplements thickly cuticularised with nerve entering anterior side of cup. No pre-or post-
cloacal setae or papillae observed. Tail short, with rounded posterior extremity, posterior half with few
short setae and ducts, some of which are not connected to setae; terminal setae not observed. Three
caudal glands and small spinneret present.
Female
Similar to males, but with smaller amphideal fovea, 2.5 turns. Reproductive system with posterior ovary
reflexed, on right of intestine; anterior ovary poorly developed (Fig. 2B). Vulva located at mid-body.
Vaginal glands present, parsproximalis vaginae surrounded by constrictor muscle.
Remarks
In contrast to Synonchiella rotundicauda sp. nov., all other Synonchiella species are characterised by
relatively long, conico-cylindrical tails with a thin cylindrical portion. S. minor is characterised by a
relatively short conical tail (2.9 abd), but can be distinguished from S. rotundicauda sp. nov. in having
smaller amphid with 1.75 turns (vs. 2.5 turns in S. rotundicauda sp. nov.), longer spicules (200 vs. 51
pm), and more pre-cloacal supplements (42-46 vv 8).
Genus Pseudocheironchus gen. nov.
urn:lsid:zoobank.org:act:D308E75C-FF 14-44 AB-9DA3-E2297C691AF6
Type species
Pseudocheironchus ingluviosus gen. et sp. nov.
Diagnosis
Cuticle without lateral differentiation or only weak lateral differentiation. Outer labial sensillae and
cephalic setae in one circle; cephalic setae slightly longer than outer labial sensillae. Anterior portion
of buccal cavity reduced, with six thin, slightly cuticularised rhabdions; posterior buccal cavity with
three equal mandibles. Pharynx short, with well-developed anterior and posterior bulbs. Male with cup¬
shaped pre-cloacal supplements. Tail short.
Etymology
This generic name refers to the close similarity between the new genus and Cheironchus. The two genera
share a feature not found in any other genus of the Selachinematidae, viz., a pharynx with conspicuous
anterior and posterior bulbs.
Remarks
Pseudocheironchus gen. nov. is similar to Cheironchus in having a pharynx with well-developed anterior
and posterior bulbs and cup-shaped pre-cloacal supplements. Pseudocheironchus gen. nov. differs from
the latter in having a cuticle without or only weak lateral differentiation (v,v. lateral differentiation of
larger, irregularly spaced punctations in Cheironchus ), cephalic setae only slightly longer than the outer
labial sensillae (vs. cephalic setae much longer than outer labia sensillae), and a posterior buccal cavity
with three equal mandibles (vs. dorsal mandible reduced). Pseudocheironchus gen. nov. is also similar
9
European Journal of Taxonomy 63: 1-32 (2013)
Fig. 4. Pseudocheironchus ingluviosus gen. et sp. nov. A. Lateral view of anterior body region of male.
B. Sublateral view of anterior body region of female. C. Surface view of female head. D. Surface
view of male head. E. Male posterior body region. F. Spicule and gubernaculum. G. Female posterior
body region. Arrow shows location of ejaculatory glands. Scale bar: A-B = 25 pm; C-D =15 pm;
E, G = 62 pm; F = 10 pm.
10
LEDUC D., Selachinematidae from the continental slope of New Zealand
to Synonchiella in having three equal mandibles in the posterior buccal cavity, but differs from the latter
in having a pharynx with anterior and posterior bulbs (vs. no pharyngeal bulb in Synonchiella).
Pseudocheironchus ingluviosus gen. et sp. nov.
Figs 4-7, Table 1
urn:lsid:zoobank.org:act:258E6E4A-6142-4A49-88B9-9A6E9B765309
Diagnosis
Pseudocheironchus ingluviosus gen. et sp. nov. is characterised by mandibles, each with two pairs of
four blunt hooks, mandibles joined by a membrane with slender cuticularised ridges at their junction,
multispiral amphideal fovea with 5.0 turns, short conical tail with rounded end, and males with spicules
1.5-1.7 abd long and 17-19 cup-shaped pre-cloacal supplements.
Etymology
The species name comes from the Latin ingluviosus (= voracious, gluttonous), and refers to the well-
developed feeding apparatus of the species.
Material examined
Holotype
NEW ZEALAND: NIWA 88356, 5 Apr. 2007, NIWA cruise TAN0705, station 38, western Chatham
Rise crest, 43.8266° S, 176.7043° E, 478 m, medium sand (45.3%), fine sand (43.9%).
Paratypes
NEW ZEALAND: 1 $, NIWA 88357,20 Feb. 2011, NIWA cruise TAN1103, station 69, central Chatham
Rise, 43.331° S, 178.288° E, 350 m, sediment depth 1-5 cm, mean grain size 55-59 pm, 55-57% sand,
particle sorting (geometric) 4.1-4.3.1 S, 1 ?, NIWA 88358, 5 Oct. 2001, NIWA cruise TAN0116, station
U2582, Chatham Rise crest, 43.4333° S, 178.5000° E, 350 m, silt/clay (37.5%), fine sand (23.4%),
medium sand (21.4%).
A
B
Fig. 5. Pseudocheironchus ingluviosus gen. et sp. nov. A. En face and side views (left and right,
respectively) of mandibles. B. Sub-lateral view of female head showing position of mandibles and
cuticularised ridges, a = mandible axis; m = membrane; r = cuticularised ridge; t = teeth. Scale bar: A =
10 pm; B = 20 pm.
11
European Journal of Taxonomy 63: 1-32 (2013)
Fig. 6. Pseudocheironchus ingluviosus gen. et sp. nov. A. Entire male. B. Entire female. Scale bar =100
pm.
12
LEDUC D ., Selachinematidae from the continental slope of New Zealand
Fig. 7. Pseudocheironchus ingluviosus gen. et sp. nov. Light micrographs. A. Female head region
showing buccal cavity and mandibles. B. Female posterior pharyngeal bulb and anterior portion of
intestine. C. Male posterior body region showing right spicule and cup-shaped supplements. D. Detail
of pre-cloacal supplements. Scale bar: A-C = 30 pm; D = 10 pm.
13
European Journal of Taxonomy 63: 1-32 (2013)
Description
Males
Body cylindrical, tapering slightly towards both extremities. Cuticle 1.5-1.8 pm thick throughout body,
thicker in tail region, 3-4 pm, with transverse rows of punctations, without lateral differentiation or
differentiation consisting of slightly larger punctations. Somatic setae short and sparse, in four sublateral
rows. Head slightly set off by constriction at level of amphid. Six conical inner labial papillae; six small
outer labial setae and four slightly longer cephalic setae (~ 0.1 cbd) situated in one circle. Amphideal
fovea situated near anterior extremity, multispiral with 5.0 turns and transversely oval outline. Anterior
portion of buccal cavity short, with six pairs of thin, cuticularised rhabdions fused proximally, ~ 6
pm long. Posterior buccal cavity with three equal mandibles, 18-21 pm long, with one mandible
situated dorsally and two sub-ventrally. Each mandible consists of a heavily cuticularised axis with a
longitudinal groove (Fig. 5A); axis is thinnest in middle portion and widens towards the posterior and
anterior extremities; anterior portion consists of two sets of four blunt hooks; posterior extremity of axis
rounded. Two thin membranes extend laterally from the entire length of each mandible (often difficult to
observe); a thin, slightly bent, cuticularised ridge is found at the junction of the membranes, one situated
ventrally and two sub-dorsally (Fig. 5A, B). Pharynx short, with conspicuous oval-shaped anterior bulb
surrounding posterior portion of buccal cavity, 23 pm wide, 29 pm long, and rounded posterior bulb, 25
pm wide. Nerve ring at middle of pharynx. Secretory-excretory (S-E) system present, cellular body of
ventral gland situated ~1.5 cbd posterior to pharynx, pore situated near posterior extremity of posterior
pharyngeal bulb. Intestine cells with numerous round inclusions, most dense in cells immediately
posterior to pharynx (Fig. 4A).
Reproductive system diorchic with short, - 50 pm long, outstretched testes. Anterior testis on left of
intestine, posterior testis on right of intestine. Small, nucleated sperm cells, oval or elongated with
pointed ends, -6x2 pm. Spicules paired, curved, 1.5-1.7 abd long, widest in middle portion and
tapering distally. Gubernaculum small, slightly bent, median part (cuneus) with hook-shaped projection
pointing dorsally (Fig. 4F). Three, perhaps four pairs of ejaculatory glands situated anterior to spicules
(Fig. 4E). Mid-ventral row of 17-19 cup-shaped pre-cloacal supplements, - 5 pm wide and 5 pm deep,
situated 5-8 pm apart. Pre-cloacal supplements thickly cuticularised, with nerve entering anterior side
of cup. No pre-cloacal seta observed. Post-cloacal setae/papillae not observed. Tail short, conical, with
rounded posterior extremity and three small terminal setae. Three caudal glands and small spinneret
present.
Females
Similar to males, but with smaller amphideal fovea with circular outline. Reproductive system
didelphic-amphidelphic with reflexed ovaries. Anterior ovary on left of intestine, posterior ovary on
right of intestine. Vulva located slightly pre-median. Vaginal glands present, pars proximalis vaginae
surrounded by constrictor muscle.
Subfamily Choniolaiminae Schuurmans-Stekhoven & Adam, 1931
Diagnosis
Buccal cavity with broad, cup-shaped anterior portion and relatively narrow posterior portion, both
reinforced by radially arranged, cuticularised rhabdions. Mandibles absent.
Valid genera
Choniolaimus Ditlevsen, 1921
Choanolaimus De Man, 1880
Cobbionema Filipjev, 1922
14
LEDUC D., Selachinematidae from the continental slope of New Zealand
Gammanema Cobb, 1920
HalichoanolaimusDQMm , 1886
LatronemaWiQSQY , 1954
Genus Cobbionema Filipjev, 1922
Type species
Cobbionema acrocerca Filipjev, 1922
Diagnosis
Four cephalic setae conspicuously longer than the outer labial sensillae, buccal cavity surrounded by
anterior pharyngeal bulb. Male with two testes pointing anteriorly and reflexed posterior testis. Short
conico-cylindrical tail.
Remarks
Cobbionema cylindrilaimoides (Schuurmans-Stekhoven, 1950) was synonymised with C. acrocerca by
Gerlach (1964) in his review of the Selachinematidae. Species descriptions were until now all based on
female specimens only.
Valid species
C. acrocerca Filipjev, 1922
C. capense Furstenberg & Vincx, 1987
Cobbionema trigamma sp. nov.
Figs. 8-10, Table 2
urn:lsid:zoobank.org:act:06CDA8B6-C525-46E9-9D04-05C4923651D8
Diagnosis
Cobbionema trigamma sp. nov. is characterised by four long cephalic setae and six smaller outer labial
setae in one circle, amphideal fovea with 4.25 turns, six rhabdions surrounding anterior buccal cavity,
each with two pairs of pointed projections at their posterior extremities, posterior buccal cavity widening
posteriorly and with three pairs of rhabdions fused posteriorly and widening anteriorly, males with two
testes pointing anteriorly and with reflexed posterior testis, spicules 2.5 abd long, and no pre-cloacal
supplements.
Etymology
The species name is derived from the Greek letter y (gamma), and refers to the presence of three pairs
of rhabdions fused posteriorly (/. e. , gamma-shaped) in the posterior buccal cavity.
Material examined
Holotype
NEW ZEAFAND: NIWA 88359, 6 Apr. 2007, NIWA cruise TAN0705, station 45, southern flank of
Chatham Rise, 44.4864° S, 177.1407° E, 1238 m, silt/clay (93.9%).
Paratypes
NEW ZEAFAND: 1 c?,NIWA88360,8 Oct. 2001,TAN0116, station U2593A, southern flank of Chatham
Rise, 44.3333° S, 178.5000° E, 1200 m, silt/clay (63.8%), fine sand (16.0%), very fine sand (13.6%).
1 J, NIWA 88361, 26 Apr. 2007, NIWA cruise TAN0705, station 271, northern flank of Chatham Rise,
42.6216° S, 175.9262° E, 1210 m, fine sand (60.3%), medium sand (29.3%).
15
European Journal of Taxonomy 63: 1-32 (2013)
Fig. 8. Cobbionema trigamma sp. nov. A. Surface view of holotype head. B. Surface view of paratype
male head. C. Buccal cavity of paratype male. D. Holotype anterior body region. E. Spicule and
gubernaculum of holotype. F. Holotype posterior body region. G. Paratype male posterior body region.
H. Female posterior body region. Scale bar: A-C = 30 pm; D = 80 pm; E = 36 pm; F-G = 70 pm; H
40 pm.
16
LEDUC D., Selachinematidae from the continental slope of New Zealand
Fig. 9. Cobbionema trigamma sp. nov. A. Entire holotype. B. Entire female. C. Entire male paratype.
Scale bar =100 pm.
17
European Journal of Taxonomy 63: 1-32 (2013)
Description
Males
Body cylindrical, tapering slightly towards both extremities. Cuticle 1.5-3.0 pm thick, thickest in tail
region, with transverse rows of punctations, without lateral differentiation except in mid-body region,
where punctations are irregularly spaced and further apart; lateral rows of oval-shaped cuticle pores, 1.5-
2 x 2-3 pm, beginning from halfway down pharynx to anterior portion of tail (Fig. 10B). Somatic setae
short and sparse, irregularly distributed. Head blunt, not set off, with six lips surrounding mouth opening.
Inner labial papillae minute; six small outer labial setae situated slightly anterior to four conspicuously
longer cephalic setae, 0.3-0.5 cbd. Amphideal fovea multispiral with 4.25 turns, with circular outline.
Buccal cavity voluminous, divided into anterior and posterior portion. Anterior portion of buccal cavity
cylindrical, with six cuticularised rhabdions, each with two pairs of large, pointed projections at posterior
extremity (Fig. 10A). Posterior buccal cavity cone-shaped, widest at posterior extremity, with three pairs
of rhabdions fused posteriorly and gradually widening anteriorly (Fig. 10A). Pharynx with conspicuous
anterior bulb surrounding posterior portion of buccal cavity and part of anterior buccal cavity; pharynx
widens posteriorly but not forming true posterior bulb. Nerve ring at 45% of pharynx length from
anterior. Secretory-excretory (S-E) system present, cellular body of ventral gland situated immediately
posterior to pharynx, pore situated 0.1-0.5 cbd posterior to nerve ring. Intestine cells with numerous
round inclusions, most dense in cells immediately posterior to pharynx (Fig. 8D).
Reproductive system with two testes pointing anteriorly, with outstretched anterior testis and reflected
posterior testis. Anterior testis on left of intestine, posterior testis on right of intestine. Large globular
sperm cells, 6-9 x 10-13 pm. Spicules paired, 2.5 abd long, curved, swollen at proximal end and at ~
55% of spicule length from proximal portion, then tapering distally. Gubernaculum bent, with lateral
pieces (crurae) flanking distal ends of spicules. Pre-cloacal supplements absent; one small pre-cloacal
seta. Tail conico-cylindrical with short, sparse setae and pointed extremity. Three caudal glands and
spinneret present.
Female
Similar to male. Reproductive system didelphic-amphidelphic with reflected ovaries. Anterior ovary on
left of intestine, posterior ovary on right of intestine. Vulva located at ~ 40% of body length from anterior
Fig. 10. Cobbionema trigamma sp. nov. Light micrographs. A. Buccal cavity of holotype. B. Cuticle of
holotype, showing cuticle pores. Scale bar: A = 25 pm; B = 12 pm.
18
LEDUC D., Selachinematidae from the continental slope of New Zealand
extremity. Pars proximalis vaginae surrounded by constrictor muscle, vaginal glands not observed.
Anus not observed.
Remarks
Cobbionema trigamma sp. nov. is similar to C. acrocerca but differs from the latter in having a
posterior buccal cavity with three pairs of rhabdions fused posteriorly and widening anteriorly, whereas
C. acrocerca possesses a posterior buccal cavity with three irregularly-spaced rhabdions narrowing
posteriorly and bearing hooks at their anterior extremities. C. trigamma sp. nov. differs from C. capense
in the absence of denticles in the buccal cavity, and in the number (24 in C. trigamma sp. nov. vs. 7 in C.
capense) and orientation of pointed projections (all pointing posteriorly vs. some pointing anteriorly in
C. capense ; pointed projections referred to as “teeth” in Furstenberg & Heyns 1987).
There was a substantial (> 2-fold) difference in size between the holotype and the paratype male. The
two males also differed in the size of the amphid (0.28 vv 0.52 cbd) and tail length (2.2. vv 2.8 abd),
but were identical in the size and arrangement of head sensillae, buccal cavity structure, and copulatory
apparatus.
The buccal cavity of Cobbionema trigamma sp. nov. closely resembles that of Halichoanolaimus.
H. robustus (Bastian, 1865), H. consimilis Allgen, 1933, H. quattiiordecimpapillatus Chitwood, 1951
and H. dolichurus Ssaweljev, 1912, for example, all have an anterior buccal cavity surrounded by
rhabdions with pointed projections or hooks (the latter often in pairs) and a posterior buccal cavity
surrounded by three pairs of rhabdions fused posteriorly (see figs 6-9 in Gerlach 1964).
The female of Cobbionema trigamma sp. nov. appears to lack an anus, a feature that has also been
observed in several Halichoanolaimiis species (Gourbault & Vincx 1985). The absence of an anus
was also noted by Schuurmans-Stekhoven (1950) in C. cylindrolaimoides (“the anal cleft could not be
located”). The latter author cast doubt on the observations of Filipjev (1922), who drew the anus of C.
acrocerca very far posteriorly near the cylindrical portion of the tail, which could suggest that the anus
is in fact absent in C. acrocerca as well.
Cobbionema trigamma sp. nov. is unusual among the Selachinematidae in the structure of the testes (two
testes anteriorly with posterior testis reflexed), and Choniolaiminae in lacking pre-cloacal supplements.
Because this is the first time that male Cobbionema specimens are described, it remains unclear whether
these are characteristic of other species of the genus.
Genus Gammanema Cobb, 1920
Type species
Gammanema ferox Cobb, 1920 (junior synonym of Gammanema rapax (Ssaweljev, 1912)).
Diagnosis
Cuticle without lateral differentiation, four slender cephalic setae; outer labia either papillose or setose.
Amphideal fovea usually spiral, rarely loop-shaped. Anterior buccal cavity large, cup-shaped, surrounded
by rhabdions with pointed projections at their posterior ends; posterior buccal cavity smaller, often with
broad column-shaped rhabdions. Pharynx without anterior or posterior bulb. Pre-cloacal supplements
present, usually cup-shaped, rarely setose or tubular. Short conical tail.
Remarks
Gammanema paramenzeli (Allgen, 1935) was considered doubtful by Gerlach (1964), Trogolaimus
uniformis Cobb, 1920 was transferred to Gammanema by Tchesunov & Okhlopkov (2006) and
G. fennicum Gerlach, 1953 was re-established as a valid species by Okhlopkov (2002).
19
Table 2. Morphometries (pm) of Cobbionema trigamma sp. nov., Gammanema agglutinans sp. nov., and Bendiella thalassa gen. et sp. nov. —
a = body length/maximum body diameter; abd = anal body diameter; b = body length/pharynx length; c = body length/tail length; cbd = corresponding
body diameter; L = body length; n = number of specimens; V = vulva distance from anterior end of body; %V = V/total body length.
European Journal of Taxonomy 63: 1-32 (2013)
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approximate values only since no anus was observed in female specimens
LEDUC D., Selachinematidae from the continental slope of New Zealand
Valid species
G. anthostoma Okhlopkov, 2002
G. cancellatum Gerlach, 1955
G. curvata Gagarin & Klerman, 2007
G. conicauda Gerlach, 1953
G. fennicum Gerlach, 1953
G. kosswigi Gerlach, 1964
G. mediterraneum Vitiello, 1970
G. polydonta Murphy, 1965
G. rapax (Ssaweljev, 1912)
G. smithi Murphy, 1964
G. tchesunovi Gagarin & Klerman, 2007
G. uniformis (Cobb, 1920)
Gammanema agglutinans sp. nov.
Figs 11-13, Table 2
urn:lsid:zoobank.org: act:3 AEB ADO 1-7722-489F -B9FF-818C5B1B8617
Diagnosis
Gammanema agglutinans sp. nov. is characterised by short, stout body (a = 10-15), cuticle with minute
spines, leaf-shaped somatic setae with ducts, sexual dimorphism in the shape of the amphideal fovea
(loop-shaped in males and spiral in females), posterior buccal cavity with three pairs of broad, column¬
shaped rhabdions fused anteriorly, intestine cells conspicuous with orange-brown granules, slightly
curved spicules, 0.8-1.0 abd long, and small tubular pre-cloacal supplements.
Etymology
The species name is derived from the Fatin word glutino (= glue, paste together) and refers to the mucus
and debris adhering to cuticle of this species.
Material examined
Holotype
NEW ZEAFAND: 3, NIWA 88362, 20 Feb. 2011, NIWA cruise TAN1103, station 69, central Chatham
Rise, 43.331° S, 178.288° E, 350 m, sediment depth 1-5 cm, mean grain size 55-59 pm, 55-57% sand,
particle sorting (geometric) 4.1-4.3.
Paratypes
NEW ZEAFAND: 1 3, 1 $, NIWA 88363, same data as holotype. 1 ? NIWA 88364, 6 Apr. 2007,
NIWA cruise TAN0705, station 45, southern flank of Chatham Rise, 44.4864° S, 177.1407° E, 1238 m,
silt/clay (93.9%).
Description
Males
Body short, stout, cylindrical, tapering slightly towards anterior extremity, covered with thin layer
of adhering mucus and small detrital particles. Cuticle ~ 1.0-1.5 pm thick, with transverse rows of
punctations, without lateral differentiation, each punctation terminating into a minute spine (spines often
difficult to observe due to presence of adhering particles). Four sub-lateral rows of leaf-shaped somatic
setae (/.<?., with narrow base, wide middle portion, and tapering distal end), each with a central duct.
21
European Journal of Taxonomy 63: 1-32 (2013)
Fig. 11. Gammanema agglutinans sp. nov. A. Surface view of female head. B. Surface view of male
head. C. Female head, showing buccal cavity. D. Female head, showing buccal cavity. E. Entire male.
F. Spicule and gubernaculum. Scale bar: A-D = 30 pm; E = 40 pm; F = 18 pm.
22
LEDUC D., Selachinematidae from the continental slope of New Zealand
4-8 pm long and 2 pm wide (Fig. 13E). Head blunt, only slightly rounded, not set off Mouth opening
surrounded by six pairs of thin, leaf-shaped cuticle extensions, 3-4 pm long (Fig. 11 A, B). Labial
sensillae in three separate circles; inner and outer labial setae conical, ~ 2 pm long, each with central
duct; four cephalic setae, each with central duct, <0.3 cbd. Loop-shaped amphideal fovea, situated <0.2
cbd from anterior extremity. Buccal cavity divided into anterior and posterior portions; anterior portion
of buccal cavity large, funnel-shaped, with twelve cuticularised rhabdions, each with one pair of pointed
Fig. 12. Gammanema agglutinans sp. nov. A. Entire female. B. Entire male. Scale bar: A= 60 pm; B =
50 pm.
23
European Journal of Taxonomy 63: 1-32 (2013)
projections at posterior extremity (Fig. 13D). Posterior buccal cavity narrow, cylindrical, surrounded
by three pairs of broad, column-shaped rhabdions fused in anterior half (Fig. 13B). Pharynx without
anterior bulb; pharynx widens posteriorly but not forming true posterior bulb. Nerve ring at ~ 40% of
Fig. 13. Gammanema agglutinans sp. nov. Light micrographs. A. Entire male. B. Buccal cavity of
female, showing paired rhabdions in posterior buccal cavity. C. Posterior region of pharynx, cardia,
and anterior region of intestine of female. D. Buccal cavity of female, showing pointed projections at
posterior extremity of rhabdions in anterior buccal cavity. E. Cuticle of male, showing punctations,
spines, and somatic setae. Scale bar A= 30 pm; B, D = 15 pm; C = 12 pm; E = 7 pm.
24
LEDUC D., Selachinematidae from the continental slope of New Zealand
pharynx length from anterior. Secretory-excretory (S-E) system not observed. Intestine cells large, well-
defined, with numerous round, orange-brown inclusions (Fig. 13A).
Reproductive system diorchic with short, outsretched testes. Testes situated either both ventrally or with
anterior testis on left of intestine and posterior testis on right of intestine; small, globular to oval-shaped
sperm cells, 2-4 x 5 pm. Spicules paired, 0.8-1.0 abd long, slightly curved, with slight constriction near
proximal extremity and tapering distally. Gubernaculum small, slightly bent at proximal end, with lateral
pieces (crurae) flanking the distal end of the spicules and a small cuneus with two small, drop-shaped
projections anteriorly (not visible in paratype male). At least six small tubular pre-cloacal supplements,
difficult to observe due to adhering particles; pre-cloacal seta present. Tail short, conical, with few
sparse sub-dorsal setae. Three caudal glands and spinneret present.
Females
Similar to male, but with conspicuously smaller spiral amphideal fovea, 1.5 turns. Reproductive system
didelphic-amphidelphic, with reflected ovaries. Anterior ovary on left of intestine, posterior ovary on
right of intestine. Vulva located at two thirds of body length from anterior extremity. Pars proximalis
vaginae surrounded by constrictor muscle, vaginal glands not observed.
Remarks
G. agglutinans sp. nov. differs from all other species in the genus in having a cuticle with spines (vs.
spines absent in all other species), males with loop-shaped amphids (vs. multispiral amphids) and leaf¬
shaped somatic setae with ducts (vs. slender setae without ducts). In addition, species of the genus are
characterised by either cup-shaped or setose pre-cloacal supplements, whereas G. agglutinans sp. nov.
is characterised by tubular supplements.
Genus Bendiella gen. nov.
urn:lsid:zoobank.org:act:8E1879A0-8BBA-4564-AAC8-E6BF123EDF0E
Type species
Bendiella thalassa gen. et sp. nov.
Diagnosis
Cuticle with lateral differentiation in the form of longitudinal rows of larger punctations. Outer labial
sensillae and cephalic setae in one circle; cephalic setae slightly longer than outer labial sensillae. Buccal
cavity large; anterior portion of buccal cavity cylindrical to funnel-shaped, with twelve cuticularised
rhabdions, each with pointed projections at posterior extremity. Posterior buccal cavity narrower,
cylindrical, surrounded by three Y-shaped pairs of slender rhabdions. Pre-cloacal supplements absent.
Tail long.
Etymology
The genus is named after Bendis, the Thracian goddess of the hunt.
Remarks
Bendiella gen. nov. is most similar to Halichoanolaimus in the shape and arrangement of the head
sensillae, structure of the buccal cavity, and in having a relatively long tail. Bendiella gen. nov. differs
from the latter, and from all other genera of the family Selachinematidae, in having a cuticle with
lateral differentiation consisting of longitudinal rows of larger dots, and from all other genera of the
Choniolaiminae (except the species Gammanema anthostoma Okhloplcov, 2002) in lacking pre-cloacal
supplements.
25
European Journal of Taxonomy 63: 1-32 (2013)
Fig. 14. Bendiella thalassa gen. et sp. nov. A. Surface view of male head. B. Surface view of female head.
C. Female head, showing buccal cavity. D. Posterior body region of male. E. Spicule and gubernaculum.
F. Posterior body region of female. G. Anterior body region of male. Arrow shows position of
lateral hypodermal gland near posterior end of intestine. Scale bar: A-C, G = 25 pm; D, F = 32 pm;
E = 13 pm.
26
LEDUC D., Selachinematidae from the continental slope of New Zealand
Bendiella thalassa gen. et sp. nov.
Figs. 14-16, Table 2
um:lsid:zoobank.org:act:31AB5540-964C-41F2-B592-F329369969DC
Diagnosis
Bendiella thalassa gen. et sp. nov. is characterised by amphideal fovea with 5.25 turns, anterior buccal
cavity with twelve rhabdions, each with a pair of pointed projections at posterior extremity, posterior
buccal cavity with three Y-shaped pairs of slender rhabdions fused from two thirds of distance from
Fig. 15. Bendiella thalassa gen. et sp. nov. A. Entire male. B. Entire female. Scale bar = 50 pm.
27
European Journal of Taxonomy 63: 1-32 (2013)
anterior ends, spicules 1.4 abd, gubernaculum consisting of two detached lateral pieces (crurae) without
median portion (corpus or cuneus), and conico-cylindrical tail, 7.0 abd long.
Etymology
The species name is derived from the Greek word thalassa (= sea).
Fig. 16. Bendiella thalassa gen. et sp. nov. Light micrographs. A. Lateral view of male cuticle. B.
Female head, showing shape of buccal cavity. C. Female head, showing details of rhabdions in anterior
and posterior buccal cavity. Scale bar =10 pm.
28
LEDUC D., Selachinematidae from the continental slope of New Zealand
Material examined
Holotype
NEW ZEALAND: $, NIWA 88365, 6 Apr. 2007, NIWA cruise TAN0705, station 45, southern flank of
Chatham Rise, 44.4864° S, 177.1407° E, 1238 m, silt/clay (93.9%).
Paratypes
NEW ZEALAND: 1 3 ??, NIWA 88366, 4 Jun. 2007, NIWA cruise TAN0707, station 98, eastern
Challenger Plateau, 40.1264° S, 170.2217° E, 804 m, silt/clay (83.3%), very fine sand (6.6%).
Description
Males
Body cylindrical, tapering slightly towards anterior extremity. Cuticle ~1.5 pm thick, with transverse
rows of punctations, lateral differentiation beginning - 1.0 cbd posterior to amphid and ending at level
of cloaca, consisting of three longitudinal rows of slightly larger dots (Fig. 16A). Somatic setae short
and sparse, irregularly spaced. Head blunt, rounded, not set off. Inner labial papillae minute; six small
outer labial setae situated in same circle as four slightly longer cephalic setae, <0.1 cbd. Amphideal
fovea multispiral with 5.25 turns, situated - 0.5 cbd from anterior extremity. Buccal cavity large, divided
into anterior and posterior portions. Anterior portion of buccal cavity cylindrical to funnel-shaped, with
twelve cuticularised rhabdions, each with one pair of pointed projections at posterior extremity (Fig.
16B, C). Posterior buccal cavity narrower, cylindrical, surrounded by three Y-shaped pairs of slender
rhabdions fused from two thirds of distance from anterior ends (Fig. 16C). Pharynx without anterior
bulb; pharynx widens posteriorly but not forming true posterior bulb. Nerve ring at - 40% of pharynx
length from anterior. Secretory-excretory (S-E) system present, cellular body of ventral gland small,
situated at posterior end of pharynx, pore situated - 0.6 cbd posterior to nerve ring. Intestine cells with
numerous round inclusions, some cells differentiated by presence of more numerous and closely packed
inclusions (Fig. 15).
Reproductive system diorchic with short, - 40-45 pm long, outsretched testes. Anterior testis on right
of intestine, posterior testis on left of intestine; small, round sperm cells, 2 pm in diameter. Spicules
paired, 1.4 abd long, curved, tapering distally. Gubernaculum consisting of two detached lateral pieces
(crurae) tapering distally; median portion of gubernaculum (corpus and cuneus) apparently absent. Pre-
cloacal supplements and seta absent. Two round hypodennal glands situated laterally at level of cloaca,
each connected to short seta. Tail 7.0 abd long, conico-cylindrical, with short, sparse setae and pointed
extremity. Three caudal glands and spinneret present.
Females
Similar to male, but with slightly smaller amphid situated 1.0 cbd from anterior extremity. Reproductive
system didelphic-amphidelphic, with reflected ovaries. Anterior ovary on left of intestine, posterior
ovary on right of intestine. Vulva located slightly pre-median. Pars proximalis vaginae surrounded by
constrictor muscle, vaginal glands not observed. Anus not observed.
Discussion
The present study brings the total number of deep-sea selachinematid species to thirteen (Miljutin et
al. 2010). Of the species described in the present study, Gammanema agglutinans sp. nov. was by far
the most common, with records from fourteen sites on Chatham Rise and Challenger Plateau (Fig.
17). Bendiella thalassa gen. et sp. nov. was also recorded from Chatham Rise and Challenger Plateau
(three sites), whereas Cobbionema trigamma sp. nov., Pseudocheironchus ingluviosus sp. nov., and
Synonchiella rotundicauda sp. nov. were only recorded at Chatham Rise sites.
29
European Journal of Taxonomy 63 : 1-32 ( 2013 )
Acknowledgements
This research was funded by NIWA under Coasts and Oceans Research programme 2 (2013/14 SCI).
Sample data were generated under the Ocean Survey 20/20 Chatham-Challenger project for which
I thank the funding agencies. Land Information New Zealand, Ministry of Fisheries, Department of
f\ Challenger
*
Chatham Rise
"tL rt
'X
lOWm
ifn—
.y>-
S. rotundicauda
C. trigamma
i*H in—
- HXW
Fig. 17. Map of the New Zealand region with 1000 m water depth contours. A. Location of the sites
sampled on Chatham Rise and Challenger Plateau. - B-F. Distributions of individual species. - B.
Pseudocheironchus ingluviosus gen. et sp. nov. C. Synonchiella rotundicauda sp. nov. D. Cobbionema
trigamma sp. nov. E. Gammanema agglutinans sp. nov. F. Bendiella thalassa gen. et sp. nov.
30
LEDUC D., Selachinematidae from the continental slope of New Zealand
Conservation and NIWA, for permission to use the data and samples. I also acknowledge the other
participants of voyages TAN0116, TAN0705, TAN0707, TAN1103, and TAN1116, and the officers and
crew of the RV Tangaroa. I am grateful to Natalia Fadeeva and an anonymous reviewer for providing
constructive criticisms on an early draft of the manuscript.
References
Decraemer W. & Smol N. 2006. Orders Chromadorida, Desmodorida and Desmoscolecida. In: Abebe
E.-A., Transpurger W. & Andrassy I. (eds) Freshwater Nematodes: Ecology and Taxonomy. 497-573.
Cambridge, UK, CABI Publishing.
Fadeeva N.P. 1988. On the study of the nematodes of the family Selachinematidae (Chromadorida,
Chonlolaimoidea). Proceedings of the Zoological Institute, Leningrad 180: 33-42 (in Russian).
Filipjev I.N. 1922. New data about free-living nematodes of the Black Sea. Transactions of Stavropol
Agricultural Institute 1: 83-184 (in Russian).
Filipjev I.N. 1926. Freilebende marine Nematoden aus der Umgebung von Sebastopol. Travaux du
Laboratoire Zoologique et de la Station Biologique de Sebastopol pres de l Academie des Sciences de
Russie, Serie II (4).
Furstenberg J.P & Heyns J. 1987. Cobbionema capense n. sp. from Swartkops estuary. Port Elizabeth
(Nematoda: Selachinematidae). Canadian Journal of Zoology 65: 80-82.
GerlachS.A. 1964. Revision der ChoniolaiminaeundSelachinematinae (freilebende Meeres-Nematoden).
Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut ( Kosswig-Festschrift ): 23-49.
Gourbault N. & Vincx M. 1985. Nematodes abyssaux (campagne Walda du N/O “Jean Charcot”). V.
Especes nouvelles de Selachinematidae, depourvues d’anus. Cahiers de Biologie Marine 16: 87-97.
Hope W.D. & Murphy D.G. 1972. Taxonomic hierarchy and checklist of the genera and higher taxa
of marine nematodes. Smithsonian Contributions to Zoology 137: 1-101. http://dx.doi.org/10.5479/
si.00810282.137
Jensen P. 1987. Feeding ecology of free-living aquatic nematodes. Marine Ecology Progress Series 35:
187-196. http://dx.doi.org/10.3354/meps035187
Feduc D. & Gwyther J. 2008. Description of new species of Setosabatieria and Desmolaimus (Nema¬
toda: Monhysterida) and a checklist of New Zealand free-living marine nematode species. New Zealand
Journal of Marine and Freshwater Re search 42:339-3 62. http://dx.doi.org/10.1080/00288330809509962
Feduc D., Probert PK. & Nodder S.D. 2012a. Two new free-living nematode species (Comesomatidae)
from the continental slope of New Zealand, with keys and notes on distribution. Zootaxa 3348: 40-55.
Feduc D., Rowden A.A., Bowden D.A., Nodder S.D., Probert P.K., Pilditch C.A., Duineveld G.C.A. &
Witbaard R. 2012b. Nematode beta diversity on the continental slope of New Zealand: spatial patterns
and environmental drivers. Marine Ecology Progress Series 454: 37-52. http://dx.doi.org/10.3354/
meps09690
Forenzen S. 1981. Entwurf eines phylogenetischen Systems der freilebenden Nematoden.
Veroffentlichungen des Instituts fur Meeresforschung in Bremerhaven Supplement 7: 1-472.
Miljutin D.M., Gad G., Miljutina M.M., Mokievsky V.O., Fonseca-Genevois V., Esteves A.M. 2010.
The state of knowledge on deep-sea nematode taxonomy: how many valid species are known down
there? Marine Biodiversity 40: 143-159. http://dx.doi.org/10.1007/sl2526-010-0Q41-4
Neira C. & Decraemer W. 2009. Desmotersia levinae , a new genus and new species of free-living
nematode from bathyal oxygen minimum zone sediments off Callao, Peru, with discussion of the
31
European Journal of Taxonomy 63 : 1-32 ( 2013 )
classification of the genus Richtersia (Chromadorida: Selachinematidae). Organisms, Diversity & Evo-
lution9\ l.el-l.el5. http://dx.doi.Org/10.1016/j.ode.2008.09.004
Okhlopkov J.R. 2002. Free-living nematodes of the families Selachinematidae and Richtersiidae in the
White Sea (Nematoda, Chromadorida). Zoosystematica Rossica 11: 41-55.
Pastor de Ward C.T. & Lo Russo V. 2007. A review of the genus Richter sia (Nematoda:
Selachinematidae): new species from Golfo San Jose and Golfo San Mafias, Chubut (Argentina). Journal
of the Marine Biological Association of the United Kingdom 87: 1153-1160. http://dx.doi.org/10.1017/
S0025315407056755
Pereira T., Martinez-Arce A., Gingold R. & Rocha-Olivares A. 2009. Direct nematode predation in the
marine nematode Synonchiella spiculora (Selachinematidae: Nematoda). Marine Biodiversity Records
2: el 11. 4 pages. http://dx.doi.org/10.1017/S1755267209001Q92
Schuurmans-Stekhoven J.H. 1950. The freeliving marine nemas of the Mediterranean. I. The Bay of
Villefranche. Memoires de l 'Institut Royal des Sciences Naturelles de Belgique 37: 1-220.
Somerfield PJ. & Warwick R.M. 1996. Meiofauna in Marine Pollution Monitoring Programmes: a
Laboratory Manual. Ministry of Agriculture, Fisheries and Food, Towestoff
Tchesunov A.V. & Okhlopkov J.R. 2006. On some selachinematid nematodes (Chromadorida:
Selachinematidae) deposited in the collection of the Smithsonian National Museum of Natural History.
Nematology 8: 21-44. http://dx.doi.org/10.1163/156854106776179890
Warwick R.M. 1971. Nematode associations in the Exe estuary. Journal of the Marine Biological
Association of the United Kingdom 51: 439-454. http://dx.doi.org/10.1017/S00253154000319Q8
Manuscript received: 24 July 2013
Manuscript accepted: 27 September 2013
Published on: 13 November 2013
Topic editor: Rudy Jocque
Desk editor: Danny Eibye-Jacobsen
Printed versions of all papers are also deposited in the libraries of the institutes that are members of
the EJT consortium: Museum National d’Histoire Naturelle, Paris, France; National Botanic Garden
of Belgium, Meise, Belgium; Royal Museum for Central Africa, Tervuren, Belgium; National History
Museum, Tondon, United Kingdom; Royal Belgian Institute of Natural Sciences, Brussels, Belgium;
Natural History Museum of Denmark, Copenhagen, De nm ark.
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