365
Soil-inhabiting nematodes of the orders Araeolaimida, Chromadorida, Enoplida,
and Monhysterida from the Canadian highArctic1
R. H. M U L V E Y
EntomologyResearch Institute, Canada Departmentof Agriculture,Ottawa, Canada
Received December 3, 1968
MULVEY, R.H. 1969.Soil-inhabiting nematodesofthe orders Araeolaimida,Chromadorida, Enoplida,
and Monhysterida from the Canadian highArctic. Can. J.Zool. 47:365-382.
Fourteen soil-inhabiting species of nematodes, including twonewspecies, are recorded from the
Canadian high Arctic. Microlaimus arcticus n.sp.andHofmaenneria hazenensisn. sp., are described
and illustrated. Twogenera, Cylindrolaimusand Achromadora, arerevised. Most oftherecorded species
are illustrated and measurements presented. Taxonomie keystospeciesinthegenera Bastiania, Achromadora, Microlaimus, andTrischistoma arepresented. The taxonomieposition ofthe genusNannonchus
Cobb, 1913isdiscussed.
Introduction
were eventually prepared. Measurements were madeby
T
means of a "Visopan" projection microscope. IllustraD u n n g June-August 1962 I collected soil t i o n s wereprepared from camera lucida drawings.
samples from the Lake Hazen area of Ellesmere
All type material is maintained in the Canadian
Island (81°49' N . , 71°18' W.) in the Northwest National Collection of Nematodes (CNCN) at Ottawa,
Territories, Canada. Many of these samples C a n a d a contained male and female nematodes of soilTaxonomy
inhabiting genera belonging to the orders I. ORDER Araeolaimida D e Coninck & SchuurAraeolaimida, Chromadorida, Enoplida, and
mans Stekhoven, 1933
Monhysterida. The present paper contains
„ _ „ D .. . -, A/r
,0,,
. j
-
s
e
J
I
J
GENUS Bastiania de M a n , 1876
taxonomie descriptions of new and already
Thls
described species in these genera and also reviS e n u s Presently contains six species,
sions of two of the genera. In addition, the vlz -> R oralis
Cobb, 1893, B. exilis Cobb,
1914 R
taxonomie position of the genus Nannonchus
> Sracilis d e M a n > 1 8 7 6 > R longicaudata
de
Cobb 1913 is discussed
Man, 1880,B. parexilis D e Coninck, 1935,
and B. octopapillata Meyl, 1961(syn.B. gracilis
var. octopapillata Meyl, 1954). The species are
Materials andMethods
d o s d y r e l a t e d a n d difficult t o s e p a r a t e o n t h e
Specimens were killed by heat and then fixed for at basis of female characters. The males, which
least 24h in 5%formol, and permanent glycerin mounts h a v e b e e n r e p o r t e d for a l l s p e c i e s e x c e p t B.
•
longicaudata, are more easily identified, having
lAn investigation associated with theprogram studies oipnifjeant differences in number of sunnlements
on Arctic insects, Entomology Research Institute, sigmncant ainerences m numoer oi supplements
Canada Department ofAgriculture (Paper No. 36).
and length of the spicules.
KEY TO SPECIES
Genus Bastiania:Females
1. Vulva situated midway in body, K = 50%
longicaudata de Man
Vulva situated posterior tomid-body, V= 56%or more
2
2. Tails fairly long, c = 8-10
exilisCobb
parexilisDeConinck
3
Tails fairly short, c = 13-24
3. Vulva well posterior to mid-body, V= 67-68%
Vulva posterior tomid-body, V= 56-62%
octopapillata Meyl
gracilisdeMan
KEY TO SPECIES
Genus Bastiania:Males
1. Supplements numerous, 90ormore
Supplements much lessnumerous, 36orless
2
3
*^mmmmm
366
CANADIAN JOURNAL OF ZOOLOGY. VOL. 47, 1969
<&'TMbrelativelylong, c — 6.6
IfcDt relatively short,c - 12.5
Dts26or morein number
Ms13orless
»lengthabout 13u,c = 30
,lengthabout 20u, c = 20~22
australis Cobb
exilis Cobb
parexilis De Coninck
4
octopapillataMeyl
gracilis de Man
fkracills de Man, 1876
(Figs. 1-3)
The specimens from the Lake Hazen area are
kales).!. = 1.47mm(1.35-1.70);a = 70 similar to de Man's (1876) description and illus„. b - 5.2 (4.8-5.7); c = 16 (13-19); tration of the female. The body lengths of the
1
(56-61); tail length = 96\i (70-120).
former are much longer than those of de Man's
30|i
30(1
1-1,3
©
©
FIGS. 1-3. Bastianiagracilis, female. 1.Head region. 2.Tail. 3. Junction of esophagus and intestine.
MULVEY: SOIL-INHABITING NEMATODES FROM THE CANADIAN ARCTIC
specimens. Female didelphic, amphidelphic,
ovaries reflexed to nearly level of vulva.*
Hirschmann (1952) illustrated thebody ofher
specimenswithirregularly scattered shortbristles.
These areabsent ontheLake Hazen specimens.
No male was found.
Habitats—Grass, humus soil, very wetcondition; moss anddrysoil supporting tufted grass.
Collection Nos. 3024, 3028, 3039, 3040, 3042,
3059, and3075.
De Man (1880, 1884)first described andillustrated the male and female of this species.
Loof (1961, p. 193) examined deMan's original
specimens and reported that the amphid was
cryptospiral rather than circular as illustrated
GENUS Rhabdolaimus de Man, 1880
Rhabdolaimus terrestris deMan,1880
(10females).!, = 0.39 mm(0.37-0.41);a =24
(20-25); é = 5 (4.3-5.9); c = 2.9 (2.6-3.5);
V = 43 (40-46); tail length = 135 JJ. (130-180).
De Man (1880, 1884) described andillustrated
the male andfemale of this species. The female
specimens from Lake Hazen area fithisdescription well.
Habitats—Moist moss and soil, sandy clay,
wet grassy areas, drysoil. Collection Nos. 3029,
3039,3041, 3045,3047,3054,3062,3065,3076-1.
GENUS Cylindrolaimusde Man, 1880
Definition emended—Cylindrolaiminae. Cuticle with fine transverse striae, without lateral
wings or bristles. Head not offset, without lips
and papillae, butwith four short setae. Amphid
cryptospiral (presenting a circular appearance
at top level). Buccal cavity a straight cylinder
or prismatic tube lined with rhabdions. Esophagus cylindrical with slightly enlarged posterior
area. Vulva midway in body, female either
didelphic, or monodelphic, ovaries or ovary
outstretched. Monodelphic species with ovary
directed anteriorly or posteriorly. Male monorchic, spicules arcuate, without midrib, gubernaculum inconspicuous, onepreanal supplement.
Tails conoid, tapering to a rounded terminus,
caudal glands andterminal duct present.
Type species—Cylindrolaimus communis de
Man, 1880.
Cylindrolaimusmelancholicus as Man, 1880
(Figs.4-7)
(8females).L = 0.71 mm(0.63-0.81); a = 30
(25-37); b = 5.4 (4.9-6.1); c = 8.4 (8.1-8.8);
V = 51 (50-54); tail length = 96u (75-100).
*In his definition of this genus Goodey (1963) describes the female as didelphic, amphidelphic with
outstretched ovaries. However, de Man's illustration
(1876, fig. 43a) of the type species B. gracilis shows
reflexed ovaries.
©
FIGS. 4-7. Cylindrolaimusmelancholicus,female. 4.
Head region. 5.Tail. 6. Junction of esophagus andintestine.7.Reproductive tract.
367
368
CANADIAN JOURNAL OF ZOOLOGY. VOL. 47, 1969
by de Man. In addition, he stated that fresh
specimens of this species which he examined
contained two ovaries and not a single ovary as
reported by de Man.
The females in the Lake Hazen collection
conform closely to those described by Loof.
Amphid cryptospiral but appearing rounded at
the top level. Junction of the esophagus and
intestine (see Fig. 6) somewhat different than
that illustrated by de Man. Female didelphic,
amphidelphic, ovaries outstretched. In some
specimens either the anterior or the posterior
ovary was obscure.
Tail conoid with bluntly rounded terminus,
caudal glands obscure, terminal duct present.
Habitats—Wet grass, humus, and moss.
Collection Nos. 3024, 3053, 3064, 3078-2, and
3080-6.
Discussionof Species inthe GenusCylindrolaimus
Goodey (1963) lists 10 species belonging to
this genus of which I consider five are possibly
valid, viz., C. communis de Man, 1880, C.
baradalanusAndrässy, 1959, C.melancholicus de
Man, 1880, C. monhystera Schneider, 1937, and
C. obtusus Cobb, 1916. These can be separated
into two groups on the basis of stomatal-head
diameter ratio (Table I), but further separation
is somewhat difficult since there exists considerable confusion about the number of ovaries in
each species. De Man (1880, 1884) reported a
single ovary for both C. communis and C.
melancholicus while Loof (1961) found that
recent specimens of both specieshad two ovaries
(Table I). Therefore, on this basis, C. baradalanus and C. communis are possibly conspecific in
that differences between these two species are
not significant.
Transferred to OtherGenera
C. aberrans Micoletzky, 1915 was placed in
synonymy of Plectus pedunculata Hofmänner,
1913,by Micoletzky (1917, 1922).Filipjev (1930)
decided that Plectus pedunculata did not belong
to the genus Plectus and erected the genus Paraplectus to accommodate this taxon. However,
Paraplectus was preoccupied (Raffray 1898) and
the name Paraplectonema was proposed by
Strand (1934).Hopper (1968)presented complete
details of the history of this species and its
present taxonomie position.
C.abnormisAllgén, 1933waspoorly described
and illustrated and onthebasis ofa singlefemale.
Schuurmans Stekhoven (1951)placed this species
in the genus Cryptonchus Cobb, 1913, having
compared a specimen he found in the Congo
with that of Allgén. Goodey (1951) described
and illustrated specimens which he collected in
Java. However, he wrongly identified his material as Gymnolaimus exilis (Cobb, 1893).
Goodey (1963) corrected this mistake but unfortunately included C. abnormis under Cylindrolaimus as well as under Cryptonchus
where it rightly belongs.
TABLE I
Comparative measurements of female Cylindrolaimus species
Species
Author
Body length,
mm
Tail length,
Ovaries
c value
V,%
baradalanus
Andrässy, 1959
0.80
Paired
50
110
7.5
communis
de Man, 1880;
1884
Loof (1961)t
0.64
Single,
posterior
Obscure
56
80
7.9
54
60
7.8
58
80
7.5
50
130
10-12
55
80
50-54
75-100
62
75
obtusus
Cobb, 1916
melancholicus de Man, 1880;
1884
Loof (1961)t
Mulveyt
monhystera
Schneider, 1937
0.43, 0.52
0.60
1.3
0.91
0.63-0.81
0.55
Single,
posterior
Single,
posterior
Obscure
Paired
Single,
anterior
*Head diameter taken at level of amphid.
fLoof used de Man's specimens, recent specimens had two ovaries.
jThis paper.
11
7.3
Stomatal
length
2i X head
diameter*
2i X head
diameter
2i X head
diameter
2i X head
diameter
H X head
diameter
l i X head
diameter
If X head
diameter
1 X head
diameter
MULVEY: SOIL-INHABITING NEMATODES FROM THE CANADIAN ARCTIC
C.brachystomaHofmänner in Hofmänner and
Menzel, 1914 is obviously not a Cylindrolaimus.
Gerlach and Meyl (1957) established a new
genus Hofmaenneria with H. brachystoma (syn.
C. brachystoma) as the type species.
C. niddensis Skwarra, 1921 was transferred to
the genus Hofmaenneria by Gerlach and Meyl
(1957). Skwarra described and illustrated this
species on the basis of a single male specimen.
Schneider (1940, p. 93) first proposed the genus
Hofmaenneria to include C. brachystoma and C.
niddensis but did not give a generic description.
Goodey (1963) considered Hofmaenneria of
Schneider as nomen nudum and assigned the
authority for this genus to Gerlach and Meyl.
C. tristis Ditlevsen, 1911 was transferred to
Cryptonchus by Filipjev (1936). Goodey (1963)
considered C. tristis as the type species of
Cryptonchus.
Incertae sedis
Cylindrolaimus lacustris Hofmänner, 1913—
Hofmänner (1913) described this species on the
basis of four females. Cobb (1916) and Micoletzky(1922)considered this speciesas belonging
to the genus Ethmolaimus de Man, 1880. However, except for the indication of a stomatal
capsule (see Fig. 10, Hofmänner 1913), which is
characteristic of Ethmolaimus, the females of
this species appear to belong to Cylindrolaimus.
Therefore, I propose the above category for this
species until more specimens are found for the
purpose of ascertaining its true generic relationship.
Cylindrolaimus macrurus Daday, 1899—Described (1899) and illustrated (1901) by Daday.
Cobb (1916) suggested that C. macrurus did not
belong to this genus. Details of the head and
shape of the tail indicate that it does not belong
in the genus Cylindrolaimus and is possibly new
to science.
Cylindrolaimus politus Daday, 1905—Daday
(1905) described and illustrated this species. The
structure and details of the head and tail do not
conform with those of Cylindrolaimus.
Speciesinquirendae
Cylindrolaimus filicaudatus Allgén, 1933—
Allgén (1933) described and illustrated this
species on the basis of two juvenile specimens,
which is inadequate for placement in any genus.
I propose this species be placed in the above
category.
369
II. ORDER Chromadorida (Filipjev, 1917) Chitwood, 1933
GENUSAchromadora Cobb, 1913
Goodey (1951, 1963) lists the genus Nannonchus Cobb, 1913as a synonym of Achromadora.
I consider (see discussion elsewhere in this
paper) Nannonchus a valid genus. In addition,
Goodey presented the male characters of N.
granulatus Cobb, 1913 in his definition of the
genus Achromadora which, of course, are not
typical of this genus. I have therefore, emended
the generic definition to include the male
characters of A. ruricola.
Definition emended—Cyatholaiminae. Cuticle
with transverse striations, having rows of
punctations. Amphids spiral, located at level of
dorsal tooth to slightly posterior of base of
buccal cavity. Head continuous with body,
rounded, with six poorly developed lips, each
with a small apical papilla. Cephalic setae 10;
buccal cavity funnel-shaped with distinct dorsal
tooth anterior to midway in cavity and one or
two small subventral teeth posteriorly. Esophagus cylindrical with enlarged basal area
forming a pseudobulb. Female didelphic, amphidelphic, ovaries reflexed. Prerectum present
or absent. Tail conoid, tapering to a bluntly
rounded terminus. Caudal glands and terminal
spinneret present.
Males rare, diorchic. Spicules bulky, gubernaculum trough-like. Supplements absent.
Type species—Achromadoraruricola(de Man,
1880) Micoletzky, 1925.
Achromadora ruricola (de Man, 1880) Micoletzky, 1925
(Figs. 8-10)
(10 females). L = 0.56 mm (0.51-0.60);
a = 22 (20-27); b = 6.0 (5.6-6.4); c = 7.6
(7.0-7.9); V = 43 (42-48); tail length = 75 \i
(70-80).
(1 male). L = 0.50 mm; a= 25; b = 5.6;
c = 8; spiculelength = 20|a;taillength = 63u..
The Lake Hazen male and females fit de
Man's description (1880) and illustrations (1884)
of this species fairly well. De Man did not
illustrate a subventral tooth in illustration of the
head. However, this could have been easily
overlooked.
None of the many specimens of this species
which I examined had a prerectum.
370
CANADIAN JOURNAL OF ZOOLOGY. VOL. 47, 1969
Habitats—About the roots of grass, wet
humus and muck soil, wet and dry moss.
Collection Nos. 3024, 3031, 3041, 3053, 3055,
3057, 3058, 3061, 3064, 3065, 3075, 3076, and
3080.
Achromadora terricola(de Man, 1880) Micoletzky, 1925
(Figs. 11-14)
(10 females). L = 0.90 mm (0.75-0.95); a =
24(22-26); b = 6.6 (6.3-6.9); c = 9.0 (8.3-9.5);
V = 49 (47-50); tail length = 100 u (90-105).
FIGS. 8-10. Achromadoraruricola. 8. Female, anterior region. 9. Male tail, spicule, and gubernaculum.
10. Female tail.
t
MULVEY: SOIL-INHABITING NEMATODES FROM THE CANADIAN ARCTIC
FIGS. 11-14. Achromadora terricola, female. 11.Head region. 12.Enface view of head at level of dorsal
tooth. 13.Enface viewof head at level of lips. 14.Tail.
371
372
CANADIAN JOURNAL OF ZOOLOGY. VOL.47, 1969
De Man described (1880) and illustrated
Stefanski (1938) described and illustrated a
(1884) this species. The Lake Hazen females male (tail area, spicules, and supplements)
conform closely in size and other details to which he assigned to this species. This is the
those ofDe Man. Illustrations byde Man donot first male reported forthe species,buttheshape
show a subventral tooth. However, Loof (1961), of the spicules and presence of several wellwho examined de Man's material found a sub- developed supplements provides doubt about
ventral tooth inone ofthe specimens. Apparent- itsbelonging tothis genus,
lyit was overlooked bydeMan.
Habitats—About the roots of grass andwet
TheLakeHazenspecimensallpossessed along moss. Collection Nos. 3030, 3032, 3059, 3075,
distinct prerectum (see Fig. 14) which appears 3076, 3077, 3078, 3079, and3080.
to bea diagnostic character for this species.
KEY TO SPECIES
Genus Achromadora: Females
1. Dorsal tooth well anterior tosubventral teeth
Dorsal tooth slightly anterior tosubventral teeth
2. Amphid wellposterior tothe baseofbuccal cavity
Amphid atbaseofbuccal cavity oranterior toitsbase
terricola (de Man)
2
longicauda Schneider
3
3. Bodylength 1.0mmormore, buccalcavitylarge0ength 20u)
Bodylength 0.7 mm orless,buccal cavity small (length 11\iorless)
4. Prerectum present, amphid atlevelofsubventral teeth
Prerectum absent, amphidsat baseofbuccal cavity
longisetae Sch. Stek.
4
5
6
5. Prerectum plus rectum length equal to anal body diameter
pseudomicoletzkyi van der Linde
Prerectum plus rectum length about four to five times anal body diameter
steinen n.nova.
syn.A.micoletzkyi Steiner
6. Tail uniformly conoid tobluntly rounded terminus
Tail conoid then cylindroid toacutelyrounded terminus
Discussion of Species intheGenus Achromadora
(See Table IIfor measurements)
Goodey (1963)lists 10species(with synonyms)
inthegenusAchromadora and oftheseI consider
six as valid (seekeyto species). In addition, I
have listed Achromadora micoletzkyi n. comb.
(Syn. Cyatholaimus micoletzkyi Steiner, 1916)
also as a valid species. However, Cyatholaimus
micoletzkyi Stefahski, 1916(transferred to the
genus ChromadorabyMicoletzky in 1922andto
Achromadora byvanderLindein1938) preempts
Steiner's C.micoletzkyi. Therefore, I propose a
new name, Achromadora steinen, for this taxon.
Incertae sedis
Achromadora dubia (Bütschli, 1873) Micoletzky, 1925—Bütschli (1873) described and illustrated this species. Hisdescription is meager
and theillustration ofthe female head doesnot
conform to that of the genus Achromadora;
therefore, I propose this taxon be placed inthe
above category.
Goodey (1963) lists several poorly described
species,viz., Cyatholaimus micoletzkyi Stefariski,
ruricola (de Man)
ambigua (Altherr)
1916, Monhystera tenax of de Man,1884,and
Ethmolaimus buetschli Schneider, 1922, as
synonyms ofA. dubia. I have also placed these
in incertae sedis until further examination of
more specimens may reveal their generic
position.
Achromadora semiarmata Altherr,1952
Described and illustrated by Altherr (1952).
The position ofthe dorsal tooth (nearly basalin
the buccal cavity) and shape of the buccal
cavity differs significantly from the description
givenforthegenus.
In addition, I propose the following beplaced
in synonymy of Achromadora inermis Altherr,
1952:
Achromadora dubia ofMicoletzky,1925
Achromadora dubiaofSchneider,1937
Achromadora dubia ofStefariski,1938
GENUS Ethmolaimus de Man, 1880
Ethmolaimus pratensis deMan,1880
(5females).L = 0.86 mm(0.80-1.00); a =21
(26-29);b = 6.4(5.7-7.1); c = 9(8-10); V =52
(50-55); tail length = 100 \i (80-130).
373
MULVEY: SOIL-INHABITING NEMATODES FROM THE CANADIAN ARCTIC
TABLE II
Comparative measurements ofAchromadora species
Species
\
•I
j
1
!
Author
Body
length, mm
c value
50
48-51
7.6
7.3
76
120
41
50
Present
6.6
60-80
43-47
Present
8X4
8.0
100
53
Present
10X4
5.5-6.0
80
44
—
8X3
7.0
86
—
—
At level of dorsal
tooth
At base of stoma
6-7.4
60-80
43-50
—
7X4
As above
7.0-7.9
70-80
42-48
Absent
8X4
As above
8.0
63
•—
8X4
As above
8.0
Spicule,
20 u
160
7.8
8.3-9.5
130
90-105
inermis
Altherr,1952
0.39-0.44(3
9 9)
de Man, 1880, 1.3
1884
fLoof (1961)
1.0
*Mulvey
0.75-0.95 (10
9 9)
Position
of amphid
8-8.5
0.4-0.5(4 9 9) 5-8
terricola
Buccal
Prerectum cavity, n
46-48
Altherr,1938
Schneider, 1937 0.35(1 9)
Schuurmans
1.03(2 9 9)
Stekhoven,
1951
micoletzkyi Steiner, 1916 0.48-0.61 (10
9 9)
pseudomico- van der Linde, 0.72
letzkyi
1938
semiarmata Altherr,1952 0.45-0.46 (25
9 9)
de Man, 1880; 0.6
ruricola
1884
Micoletzky
0.36-0.62
(1925)
*Mulvey
0.51-0.60 (10
9 9)
0.5(1 &)
v,%
100
ambigua
longicauda
longisetae
Tail
length, n
Absent
• — •
9X4
• — •
—
20X7
Large
49
47-50
—.
Present
.—.
14X7
Base ofbuccal
cavity
Well posterior to
base of buccal
cavity
As above
At level of dorsal
tooth
At level of subventral teeth
As above
At level of dorsal
tooth
As above
As above
'This paper.
fLoof used deMan's material.
I have identified the females from Lake
Hazen as belonging to this species, which was
described (1880) and illustrated (1884) by de
Man and later in greater detail by Hirschmann
(1952).
Habitats—About the roots of grass, wet
humus soil, and wet moss. Collection Nos.
3024, 3029, 3047,and3076.
GENUS Microlaimus de Man, 1880
Microlaimus arcticusn.sp.
(Figs. 15-17)
(8females). L = 0.38 mm(0.32-0.40); a = 22
(20-32); 4 = 6 (5-7); c = 7.2(6.7-8.2); V = 50
(48-55); tail length = 51u (48-55).
Female {holotype)—L = 0.4 mm; a =20;
b = 5.6; c = 6.7; V = 50; tail length = 60 \i.
Collection No.3077 CNCof Nematodes. Type
slideNo. 166depositedintheCanadian National
Collection ofNematodes, Ottawa, Canada.
Head rounded, cephalic setae four. Glandular
area between esophagus and intestine (anterior
extension ofintestine)distinct. Female didelphic,
amphidelphic, ovaries renexed. Reproductive
tract short.
Tail conoid, tapering to acutely rounded
terminus. Caudal glands three, leading to a
terminal duct.
All species of Microlaimus (freshwater) described so far have outstretched ovaries. The
new species described here is an exception, but
there seems no doubt that it belongs to this
genus.
Differential diagnosis—M. arcticus n. sp.
resembles M. globiceps deMan, 1880but differs
in having renexed ovaries and an anterior
extension of the intestine. From M. setosus
(Hoeppli, 1926) Goodey, 1963 it differs in
having reflexed ovaries.
Paratypes—Eight females in the CNC of
Nematodes, Ottawa, Canada.
Type locality andhabitat—Swampy wet area,
about theroots ofgrass, near Skeleton Lake.
Goodey (1963) listsfivenon-marine speciesof
Microlaimus asvalid, viz., M. globicepsdeMan,
1880, M. honestus Meyl, 1954 {lapsus for M.
honestoides Meyl, 1954), M. (Microlaimoides)
lingi Hoeppli &Chu,1932, M. pygmaeus Meyl,
1954, andM. {Microlaimoides)setosus Hoeppli,
374
CANADIAN JOURNAL OF ZOOLOGY. VOL. 47, 1969
FIGS. 15-17. Microlaimus arcticus n. sp.,female. 15.Reproductive tract. 16.Tail. 17.Anterior region.
1926. He also considered the subgenusMicrolaimoides Hoeppli, 1926 a synonym ofMicrolaimus.
All except M. lingi appear to be valid species
belonging to the genus Microlaimus. M. lingi,
described and illustrated by Hoeppli and Chu
(1932)onthebasisofthreemales(nofemalewas
k
recorded) does not conform to the description
of the genus Microlaimus in either the number
of cephalic setae (10 for M. lingi)nor in tail
shape. Therefore, for the present it is best
regarded as incertae sedis. Andrâssy (1960)
suggested this species belonged to the genus
Theristus.
MULVEY: SOIL-INHABITING NEMATODES FROM THE CANADIAN ARCTIC
KEY TO NON-MARINE SPECIES
GenusMicrolaimus
1. Intestine with anterior extension
Intestine without anterior extension
2. Ovaries outstretched
Ovariesreflexed
3. Tail relatively long (c = 4.7)
Tail relatively short (c = 10-11)
4. Tail conoid with acutely rounded terminus
Tail conoid then cylindroid to a bluntly rounded terminus
2
3
setosus (Hoeppli)
arcticusn.sp.
.pygmaeus Meyl
4
globiceps de Man
honestoides Meyl
FIGS. 18-20.Tripylaaffinis,female. 18.Tailregion. 19.Headregion.20.Enfaceviewofheadatleveloflips.
375
376
III.
CANADIAN JOURNAL OF ZOOLOGY. VOL.47, 1969
ORDER
Enoplida (Baird, 1853) Chitwood,
1933
„, . , _, .
.„„
GENUS Tripyla Bastian, 1865
T. sheri, in this genus. In 1965 Brzeski synonymized Tripylina with Trischistoma and listed T.
pellucidum Cobb, 1913as the type species for
this
ug>
Goodey (1963) lists 18speciesasvalidforthis
genus butnotes that twoofthese, T. conicauda- Tripyla affinisdeMan, 1880
(Figs. 18-20)
turn (Sch. Stek., 1951) Goodey, 1963 and T.
( 1 0 females). L = 1.5 mm (1.4-1.7); a = 27
cornuta Skwarra, 1921, should be considered as (23-28); b = 5.3 (4.8-5.9); c = 6.4 (5.6-7.5);
species inquirendae. Brzeski (1964) revised the v = 5 1 (49-53); tail length = 235\x(200-250).
De M a n
genus Tripyla including a keyto the following
described (1880) and illustrated
1884 t h e m a l e a n d f e m a l e o f thi
species: T. affinis, T. cornuta, T. filicaudatus, T. (
)
s species.
glomerans, T. setifera, and a new species, T. Brzeski (1964) and Loof (1961) described and
tenuis. He redescribed and illustrated all the illustrated specimens which they considered as
previously described species. Other species, belonging to this species. The latter worker
previously considered valid species, were either u s e d d e Man's original material inhis consideraplaced in species inquirendaeorin synonymy of *ion °f T. affinisasa valid species,
The Lake Hazen
nominal species listed above.
specimens, of which only
Brzeski (1964) also described a new genus, females were found, are larger than those of
Paratripyla, for which he designated P. minuta e i t h e r Brzeski or of Loof but otherwise fit the
n. sp.as the type andtransferred Tripyla inter- description ofthis species adequately.
media Biitschli, 1873to this newgenus.
Habitats—Wet anddrymoss andgrass roots.
Goodey (1963) synonymized the genus Tris- Collection Nos. 3028, 3032, 3064, and3079.
chistoma Cobb, 1913with Tripyla but gave no
GENUS
reason. On the basis of information available
Trischistoma Cobb,1913
and examination of specimens which I consider Trischistoma arenicola (de Man, 1880)Schuuras belonging to the genus Trischistoma, I conmans Stekhoven, 1951
(Figs. 21-23)
sider Brzeski (1965) had good grounds for
DeMan described (1880)andillustrated (1884)
accepting itasa valid genus.
the female of this species. Brzeski (1963) deFemales of Trischistoma are monodelphic scribed and illustrated female specimens from
whilethoseofTripylaare didelphic.The cephalic Poland which heconsidered asbelonging to this
setaeinthe former are very long (generally more species.
than one-half the head width), while those of
The Lake Hazen specimens fit de Man's
the latter arevery short (with the exception ofT. description well but, on the average, have a
setifera, which has setae about one-third the much longer body. Female monodelphic, prohead width). Brzeski (1963) described a new delphic, ovary reflexed.
genus, Tripylina, designated T. arenicola (de
Habitats and locations—Moss and grass,
Man, 1880) as thetype species andincluded T. sandy soil. Collection Nos. 3028, 3042, 3045,
monohystera (deMan, 1880) anda newspecies, and3059.
KEY TO SPECIES
Genus Trischistoma
1. Vulva posteriad {V= 80%ormore)
Vulva 70%orlessofbody length
2
3
2. Bodylength about 0.6mm
Body length about 1.8mm
.pellucidum Cobb
monohysterade Man
3. Buccal cavity with a small subventral tooth forward ofdorsal tooth
Buccal cavity without small subventral tooth forward ofdorsal tooth
GENUS TobrilusAndrâssy, 1959
Tobrilusgracilis (Bastian, 1865) Andrâssy,1959
(6 females). L = 2 . 1 mm (1.8-2.7); a =46
(38-48); b = 5.1 (4.9-5.6); c = 8.7 (8.6-10.8);
sheriBrzeski
arenicola de Man
V = 49 (48-51); tail length = 210\i (180-250).
Bastian (1865) described and illustrated this
species.The female specimens from Lake Hazen
areafithisdescriptions very well.
377
MULVEY: SOIL-INHABITING NEMATODES FROM THE CANADIAN ARCTIC
30fi
30(i
-J 22
-121,23.
FIGS. 21-23. Trischistoma arenicola, female. 21. Head region. 22.Tail. 23.Enface viewofhead atlevel of
lips.
Habitats and locations—Wet humus soil,
moss, grass roots. Collection Nos. 3024, 3057,
3068, and3075.
IV. ORDER Monhysterida (Oerley, 1880) Sch.
Stek. &DeConinck, 1943
GENUS Monhystera Bastian, 1865
Monhystera disparBastian,1865
(10 females). L = 0.61 mm (0.46-0.70); a =
25 (20-30);b = 4.6(3.8-5.1); c = 5.6(4.2-6.5);
V = 64(59-66); tail length = 110u (100-115);
T/ABD = 7.
Bastian (1865) described and illustrated this
species. De Man (1880, 1884) described and
illustrated, in much greater detail than Bastian,
a female which he considered as belonging to
this species. The Lake Hazen specimens fit de
Man's description well.
378
CANADIAN JOURNAL OF ZOOLOGY. VOL. 47, 1969
Cephalic setae very short, possibly 10 in
number. Amphids very small, approximately
one-sixth width of head diameter. Body plump.
Female monodelphic, prodelphic, ovary outstretched. Tail conoid, caudal glands distinct,
tail terminus slightly expanded, acutely rounded
at tip.
Habitats—About the roots of grass growing
in wetareas, moss, and wethumus. Collection
Nos. 3024, 3028, 3039, 3047, 3055, 3058,and
3077.
Monhystera vulgarisdeMan, 1880
(10 females). L = 0.64mm (0.55-0.74); a =
32 (27-35);b = 4.2(3.8-4.9); c =4.0(3.7-4.6);
V = 61 (58-63); tail length = 160 LI(140-190);
T/ABD = 12.
De Man (1880, 1884)described and illustrated
the female of this species. The Lake Hazen
specimens fit de Man's description well but
differ intail length from those ofGoodey (1963)
which hada much shorter tail (c = 4.7-5.5 for
those of Goodey and c = 3.4 for those of de
Man).
Cephalic setae short, amphid approximately
one-quarter as wide as head diameter. Female
monodelphic, prodelphic, ovary outstretched.
Tail conoid, then tapering toanacutely rounded
terminus.
Habitats—About the roots of grass growing
in wet areas, wetmoss, and humus. Collection
Nos. 3024, 3075, 3079, 3080.
Monhystera paravillosa Meyl,1954
(10females).L = 1.2mm(1.15-1.30); a = 40
(38-46); b = 5.2 (4.7-6.0); c = 6.5 (5.8-7.2);
V = 80(76-82); tail length = 190 LI(170-240);
T/ABD = 9.
Meyl (1954) described andillustrated themale
and female of this species. The Lake Hazen
females differ from those of Meyl in having
fewer bristles along thebody.
Cephalic setae long, about one-half as long
as head width, at least 10in number. Amphid
wide, one-third width ofhead diameter. Female
monodelphic, ovary anterior, outstretched. Caudal glands three, tail conoid, tail terminus acutely rounded with spinneret.
Habitats—Dry and wet moss and soil about
grass roots. Collection Nos. 3028, 3029, 3030,
3075.
GENUS Hofmaenneria Gerlach and Meyl, 1957
Hofmaenneria hazenensisn.sp. (Figs. 24, 25)
(4females).L = 0.41 mm(0.37-0.46); a = 48
(46-55); b =4.3 (4.2-4.4); c =4.3 (4.0-4.6);
V = 59-60; tail length = 100LI(85-115).
Female (holotype)—L =0.46 mm; a =46;
b = 4.2; c = 4.0; V = 59; tail length = 115 u.
Collection No. 3065,CNCN, Ottawa, Canada.
Type No. 167 deposited in CNCN, Ottawa.
Head setae six,more than one-half width of
head, cuticle smooth. Amphid aperture circular,
about 3LI in diameter. Female monodelphic,
prodelphic, ovary outstretched.
Tail conoid, terminus acutely rounded, caudal
glands absent.
Differential diagnosis—H. hazenensis n. sp.
differs significantly from H. brachystoma (Hofmänner in Hofmänner and Menzel, 1914)
Gerlach and Meyl, 1957 in tail shape and relative length (c = 5.8-6.4 for the latter species).
Paratypes—Three, deposited in the CNCof
Nematodes, Ottawa, Canada.
Type locality andhabitat—About theroots of
Dryas sp., moist, sandy soil, near base camp.
GENUSPrismatolaimus de Man, 1880
Prismatolaimus intermedins (Biitschli, 1873)de
Man, 1880
(Figs. 26-29)
(4females).L = 0.72 mm(0.65-0.78); a = 53
(50-56); b = 4.4 (4-5); c = 2.7 (2.5-2.9); V =
45 (43-49); tail length = 260u (240-270).
Biitschli (1873) described and illustrated this
species with the following measurements: L =
0.4-0.6 mm; a = 35-45; c = 3.0; V = 47;
tail length = 140-200 u.
The Lake Hazen specimens, except for a
greater average body length, fit Biitschli's
description fairly well.
Cephalic setae 10, female monodelphic, ovary
anterior, reflexed. Tail cylindroid with a terminal projection.
Habitats—Wet humus soil and moss. Collection Nos. 3024, 3054, 3055,3064.
GENUS Nannonchus Cobb, 1913
Definition—Cyatholaiminae (?). Cuticle with
transverse striations, longitudinal striations
throughout entire length of body. Amphids
spiral, posterior to base of buccal cavity. Head
continuous, with three well-developed lips,
MULVEY: SOIL-INHABITING NEMATODES FROM THE CANADIAN ARCTIC
FIGS. 24,25.Hofmaenneria hazenensis n. sp., female. 24. Tail region. 25.Head region. FIGS. 26-29.Prismatolaimus intermedins, female. 26.Head region. 27.Tail. 28. Junction of esophagus and intestine. 29.Tail
area enlarged.
379
380
CANADIAN JOURNAL OF ZOOLOGY. VOL. 47, 1969
30(i
-J 3 1 , 3 2
20(i
'30
FIGS. 30-32.Nannonchusgranulatus. 30.Headregion,female. 31. Maletail,posterior area. 32. Spiculeand
gubernaculum, male. (From N. A. Cobb's original illustrations.)
without apical papillae. Cephalic setae 10,
finger-like. Buccal cavity irregularly conoid,
dorsal tooth midway in cavity. Subventral teeth
absent. Esophagus cylindroid, with enlarged
basal area but without valvular apparatus.
Distinct constriction between esophagus and
intestine. Female didelphic, amphidelphic, ovaries reflexed. Tail conoid then cylindroid to a
bluntly rounded terminus. Spinneret and caudal
glands present.
Male spicules straight, proximal ends not
cephalated. Gubernaculum well-developed, irregularly shaped.
Type species—Nannonchus granulatus Cobb,
1913.
Nannonchus granulatus Cobb, 1913
(Figs. 30-32)
Female—L = 1.1 mm; a = 23; b = 5.9; c—
11.1 ; V = 52 (after Cobb, 1913).
Male—L = 1.3 mm; a = 27; b = 6.6; c =
5.5; spicule length = 37 LI(after Cobb, 1913).
Cobb (1913)described and illustrated the male
and female of this species. He erected a new
genus, Nannonchus, to accommodate the new
species. Goodey (1951) considered this genus as
a synonym of the genus Achromadora Cobb,
1913. However, the significant differences in
buccal cavity structure, in shape and size of the
male spicules and gubernaculum, and in details
of the tail between these two genera is, in my
MULVEY: SOIL-INHABITING NEMATODES FROM THE CANADIAN ARCTIC
opinion, sufficient to consider Nannonchus a
valid genus. Gerlach (1957) described and
illustrated a male and a female which he considered as belonging to this species.
Cobb's description (1913, p. 442) did not
include some pertinent information which is
contained in his original notes. He remarked
that the reflexed, tapering ovaries reached about
halfway back to the vulva and contained six or
more developing ova. The thin-shelled eggs were
more or less ellipsoidal, about as long as the
body is wide. The tail was conoid in the anterior
half and thence onward cylindrical to the
terminus, which was rounded, unarmed, and
with a well-developed spinneret. The tail of the
malewas like that of thefemale in form, except
that the posterior cylindroid portion was relatively shorter.
Habitat and localities—Roots of aquatic
plants, Potomac River, Arlington, Virginia, and
Long Key, Florida, U.S.A.; mangrove district
of Cananéia, Brazil (marine).
Acknowledgments
I am indebted to the Defence Research Board,
Ottawa, and to Dr. G. Hattersley-Smith, the
leader of Operation Hazen, for making available the facilities at Hazen Camp. Thanks also
to Dr. A. M. Golden, Section of Nematology,
U.S. Department of Agriculture, Beltsville,
Maryland, for the loan of N. A. Cobb's original
notes concerning the genus Nannonchus.
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