Leptolaimids (Nematoda, Leptolaimina) from the Canary Islands

              Rev. Acad. Canar. Cienc, XXIII (Num. 3), 1 1-24 (201 1 ) (publicado en abril de 2012)
LEPTOLAIMIDS (NEMATODA, LEPTOLAIMLNA)
FROM THE CANARY ISLANDS
R. Riera *, J. Nunez- & >1.C. Brito-
' Centro de Investigaciones Medioambientales del Atlantico (CIMA SL)
Arzobispo Elias Yanes. 44. 38206 La Laguna. Tenerife. Canar\ Islands. Spain
- Benthos Lab. Department of .Animal Biology. Faculty of Biology
University of La Laguna. 38206 La Laguna. Tenerife. Canan. Islands. Spain
*corresponding author: rodrigo(a cimacanarias.com
RESUMEN
Siete especies pertenecientes al suborden Leptolaimina fueron colectadas durante un
estudio ecologico de los fondos blandos en la costa sur de la isla de Tenerife (islas Canarias).
Dos de estas especies {Dasyuemoides sp. y Metadasynemella sp.) fueron detenninadas a ni\el
generico por la falta de material en buenas condiciones. Las especies restantes fueron Cama-colaimus
tardus De Man, 1889. Ceramonema yiinfengi Piatt & Zhang, 1982, Diodontolaimus
sabulosits Southern. 1914 Tanriia aff. peruvensis Nichols & Musselman. 1979 y Southeruia
zosterae AWgQn, 1929. Se realiza una descripcion detallada. figuras y datos meristicos de cada
una de las especies, asi como datos autoecologicos de las localidades de muestreo.
Palabras clave: Nematoda. Leptolaimina. \ida libre. fondos blandos. Tenerife. islas
Canarias.
ABSTR.\CT
Seven species belonging to the suborder Leptolaimina were collected during an eco-logical
study of the soft-bottoms on the south coast of Tenerife. Canar\' Islands. Two of these
species {Dasyuemoides sp. Metadasynemella sp.) were detemiined to genus le\ el due to the
lack of material in good conditions. The remaining species were Camacolaimus tardus De
Man, 1889, Ceramonema yunfengi Piatt & Zhang. 1982. Diodontolaimus sahulosus Southern.
1914 Tanaia aff. peruvensis Nichols & Musselman. 1979 and Southernia zosterae Allgen,
1929. Descriptions, figures and meristic data of each species are presented, as well as. auto-ecological
data of the sampling stations.
Key words: Nematoda. Leptolaimina. Free-li\ ing. soft-bottoms. Tenerife. Canary Islands.
INTRODUCTION
The suborder Leptolaimina Lorenzen. 1981 comprises a heterogeneous group of gen-era
with rather few characters in common, that are all those taxa of the order Chromadorida
11
which do not belong to the suborders Chromadorida and Desmoscolecina (Lorenzen [9]).
Some common features could be cuticle always striated, labial sensilla minute or inconspic-uos,
outer labial and cephalic setae in different circles and cephalic ones usually longer than
outer labial setae. In addition, amphids are ventrally-spiral or non-spiral, buccal cavity minute
and, in most of the cases, tubular. Males have two testes and females two ovaries.
During an ecological study of the intertidal and shallow subtidal soft-bottoms from
two stations on the south coast of Tenerife, several specimens belonging to the suborder Lep-tolaimina
were collected. A more detailed study revealed that those individuals belong to 7 dif-ferent
taxa: Camacolaimus tardus De Man, 1889, Ceramonema yunfengi Piatt & Zhang, 1982,
Dasynemoides sp., Diodontolaimus sabulosus Southern, 1914, Metadasynemella sp., South-ernia
zosterae AWgQn, 1929 and Tarvaia aff. peruvensis Nichols & Musselman, 1979.
MATERIAL AND METHODS
Samples were collected in soft-bottoms of the intertidal and shallow subtidal (3 m
deep), of Los Abrigos (SE Tenerife) and Los Cristianos (SW Tenerife). 4.5 inner diameter
PVC cores were taken to a depth of 30 cm in the sediment. These samples were fixed with 10%
formaldehyde in seawater for one day and decanted through a sieve of 63 mm mesh size, and
posteriorly preserved in 70% ethanol. Specimens were mounted in glycerine gel and drawings
of these were done using a camera lucida on a Leica DMLB microscope equipped with No-marski
interference contrast. All measurements are in micrometers and curves structures are
measured along the arc.
To assess the granulometric composition of the sediment, ca. 1 00 g of sediment from
each monthly sample was oven dried at 105°C, passed through a graded series (2 mm, 1 mm, 0.5
mm, 0.25 mm, 0.125 mm and 0.063 mm) of sieves, and then weighted (Buchanan [5]). The
method of Walkley & Black [17] was used to determine the organic matter content (% OM) of
the sediment. Total nitrogen (%) was determined following the Kjeldahl method (Bradstreet [4]).
SYSTEMATICS
Subclass CHROMADORIA Pearse, 1 942
Order CHROMADORIDA Chitwood, 1 933
Suborder LEPTOLAIMINA Lorenzen, 1981
Family Leptolaimidae Orley, 1880
Genus Camacolaimus De Man, 1889
Camacolaimus tardus De Man, 1889
(Fig. l,Tab. 1)
Camacolaimus tardus De Man [6] 184, fig. 2 a-e; Wieser [18] 27, fig. 198 a-g; Vitiello [16]
681,fig. 24a-d.
Camacolaimus australis AWgQn [2] 125, fig. 17 a-e.
Meristic data and studied material.- Tenerife, Abrigos intertidal: august 2000, 1 male ((j\) and 1 ju-venile
(Juvenil 1).
12
Description.- Male. Body slender, tappering towards both ends. Head slightly round and not
set off. Cuticle annulated, lacking lateral differentiation. Amphids are 46% of the correspon-ding
body diameter in width, round and unispiral. located at 1 \im from the anterior end. Buc-cal
cavity narrow, with a style-like tooth. Inner and outer labial setae absent. 4 cephalic setae
0.9 anal diameters long, located in the anterior part of the head. Subcephalic setae lacking.
Pharynx slender and cylindrical.
The reproductive system is diorchic with two anterior testes. Spicules 1.4 anal diam-eters
long, paired, arcuated and without capitulum. Gubemaculum 0.6 anal diameters long,
with a dorsoventrally directed apophysis. Precloacal supplements absent. Tail 4.4 anal diam-eters
long, cylindrical with posterior tip consisting of thin cuticle. Caudal setae lacking. Spin-neret
developed.
Discussion.- Canarian specimens present a larger gubemaculum and a dorsolaterally directed
apophysis, being dorsocaudally directed in individuals from other geographical areas. Cephalic
setae are larger (0.9 cephalic diameters) compared to british specimens (0.6 cephalic diame-ters)
(Piatt & Warwick [12]).
1 Juvenile 1
Total body length 1433 1314.3
a 33.4 33.5
b 6.3 5.9
c 12.6 15.3
Cephalic diameter 16 39.3
Outer labial setae — 7.1
Cephalic setae 14.3 8.6
Buccal cavity diameter 2.9 7.1
Amphid diameter 5.7 5.7
Amphid height 5.7 5.7
Amphid from anterior 2.9 4.3
Pharynx length 228.6 221.4
Phar\'nx cbd 39.3 39.3
Maximum body diameter 42.9 39.3
Spicule length 37
Gubemaculum length 17
s' 1.4
Tail length 114 85.7
Anal body diameter 26 32.1
c" 4.4 2.7
Spicule length/Tail length 0.3
Table 1.- Measurements of Camacolaimus tardus in |.im.
Ecology.- This species was collected in medium sands (Qs^ = 0.38). with a ver\' good selec-tion
(Sq = 0.87). The organic matter content was 1.11 % and carbonates percentage was 5. 1 3%.
13
Distribution.- Cosmopolitan (Lorenzen [9]). This species is first recorded from the Canary Islands.
B
Figure 1.- Camacolaimus tardus. Male. A. Anterior end. B. Posterior end. Scale A = 12 |im, B = 19 fim.
Diodontolaimus sabulosus Southern, 1914
(Fig. 2, Tab. 2)
Diodontolaimus sabulosus Southern [15] 31, fig. 11; Piatt & Warwick [12] 420, fig. 196;
Palacin[ll]319.
Meristic data and studied material.- Tenerife, Abrigos intertidal: June 2000, 1 male (c5^1) and 1 juve-nile
(Juvenile 1), april 2001, 1 male {S2).
Description.- Male: Body slender, attenuating on both ends. Head set off Cuticle annulated,
without lateral differentiation. Amphids 26% of the corresponding body diameter in width,
unispiral, located at 2 \m\ from the anterior end. Buccal cavity conical, with a noticeable dorsal
tooth. Inner and outer labial setae lacking. 4 cephalic setae 0.9 cephalic diameters long, situated
in the median part of the head. Subcephalic setae absent. Ventral gland and nerve ring not seen.
Reproductive system not discernible. Spicules 1 anal diameter long, paired, arcuated
with a capitulum. Gubernaculum 0.3 anal diameters long, with a dorsoventrally directed
apophysis. 13 precloacal supplements 23 |im long, being the posteriormost located at 29 jam
from the cloaca. Tail 1.8-2.1 anal diameters long, conical with an acuminated tail tip. Caudal
setae lacking. Spinneret inconspicuous.
Discussion.- Canarian specimens bear 13 precloacal supplements, being observed 9 or 11
precloacal supplements in this species (Southern [15]; Vitiello [16]). Moreover, a papilla lo-cated
between 4°-5° precloacal supplement (Vitiello [16]) is lacking in the studied material.
Ecology.- This species was collected in medium sands (Q50 = 0.32-0.36), with a very good se-lection
(Sq = 0.79-0.84). The organic matter content ranged from 0.96% to 1.30% and car-bonates
percentage varied between 4.44% and 6.15%.
Distribution.- Amphiatlantic (Hopper & Myers [7]; Piatt & Warwick [12]). Mediterranean
Sea(Palacin[ll]).
14
1 2 Juvenile 1
Total body length 3442.9 2714.3 1600
a 45.9 42.2 26.7
b 11.5 31.1 7.5
c 37.1 47.5 21.3
Cephalic diameter
14 14.3 10
Cephalic setae
13 13.1 17.1
Buccal ca\ ity diameter 5.7 7.1 4.3
Amphid diameter 7.1 7.1 7.1
Amphid height 7.1 5.7 4.3
Amphid from anterior 4.3 4.3
Pharynx length 300 87.1 214.3
Pharynx cbd 64.3 57.1 57.1
Maximum body diameter 75 64.3 60
Spicule length 53 44.3
Gubemaculum length 16.1 12.4
s' 1 1.1
Tail length 92.9 87.1 75
Anal body diameter 51 41.5 53.6
c' 1.8 2.1 1.4
Spicule length Tail length 0.6 0.5
Table 2.- Measurements of Diodontolaimiis sabiilosus in |im.
Distribution.- This species is first recorded from the Canary Islands.
Figure 2.- Diodontolaimiis sahiilosiis. Male. A. Anterior end. B. Posterior end. Scale A = 10 um. B = 15 }.un.
15
Family Tarvaiidae Lorenzen, 1981
Tarvaia 2iii. peruvensis Nichols & Musselman, 1979
(Fig. 3; Tab. 3)
Taj-vaia peruvensis Nichols & Musselman [10]: 125, fig. 1 a-c; Lambshead [8]: 67, fig. 8 a-f.
Meristic data and studied material.- Tenerife, Abrigos subtidal: June 2000, 1 juvenile (Juvenile 1).
Description.- Juvenil: Body slender, tappering towards both ends. Head round, slightly set off
with a cephalic capsule. Cuticle ornamented with transversal annulations, lateral differentia-tion
lacking. Amphids are 86% of the corresponding body diameter in width, large, "U-in-verted"
shape, located at 4 |im from the anterior end. Buccal cavity small and enlarged, without
noticeable teeth. Inner and outer labial setae absent. 4 cephalic setae 1 .3 head diameters long,
situated in the anterior half of the cephalic capsule. Subcepahlic setae lacking. Pharynx slen-der
and cylindrical.
Reproductive system not devel-oped.
Precloacal supplements absent.
Tail 3.9 anal diameters long, cylindrical,
with posterior tip truncated. Caudal setae
lacking. Spinneret developed.
Discussion.- The examined specimen
closely resembles Tarvaia peruvensis
Nichols & Musselman, 1979 in amphid
shape, the presence of a anterior cuticu-larized
shield and having amphids inside
the cephalic capsule. This species was
determined as Tan^aia aff. pruvensis due
to the lack of aduh specimens.
Ecology.- This species was collected in
medium sands (Q50 = 0.26), with a very
good selection (Sq = 0.75). The organic
matter percentage was 1 .54% and 6.84%
of carbonates content.
Distribution.- East Pacific (Nichols &
Musselman [10]). This species is first
recorded in the Atlantic Ocean.
Juvenile 1
Total body length 1342.9
a 44.8
b 10.5
c 18.4
Cephalic diameter 46.4
Inner labial setae 15
Cephalic setae 19
Amphid height 12.9
Amphid from anterior 30
Pharynx cbd 128
Maximum body diameter 35
Vulva from anterior 35
%V nd
Spicule length nd
Gubemaculum length
Tail length
Anal body diameter 72.9
c' 18.6
Spicule length/Tail length 3.9
Total body length
Table 3.- Measurements of Tarvaia aff. peruvensis in |am;
nd= no discernible.
16
Figure 3.- Tonaia aff. peruvensis. Juvenil. A. Anterior end. B. Posterior end. Scale = 15 urn.
Family Aegialoalaimdae Lorenzen, 1981
Soiithernia zosterae Allgen. 1929
(Fig. 4. Tab. 4)
Southenua zosterae W\%Qn [1] 427, fig. 3; Allgen [3] 148. fig. 74 a. b.
Soiithernia rubra Schulz [14] 405, fig. 41 a-e.
Meristic data and studied material.- Tenerife. Abrigos siibtidal: October 2000. 1 male (fl)-
Description.- Male: Body slender, slightly tappering towards both ends. Head round and not
set otY. Cuticle annulated with trans\ ersal striations. lacking lateral differentiation. Amphids
are 63% of the corresponding body diameter in widht. simple, strongly cuticularised (in
plaque) and round, located at 5 um from the anterior end. Buccal ca\ity minute and unarmed.
Inner and outer labial setae absent. 4 cephalic setae 0.5 head diameters long, located at the me-dian
part of the head. Subcephalic setae absent. Phar\'n.\ short, poorly de\ eloped and without
define posterior bulb.
Reproducti\ e system not discernible. Spicules 0.4 anal diameters long, paired, arcu-ated,
proximally cephalated. Tail 2.3 anal diameters long, cylindrical \\ ith a rounded posterior
tip. Precloacal supplements and caudal setae absent. Spinneret poorly developed.
Discussion.- This species is characterized by ha\ ing an amphid in plaque, gubernacular
apophyses dorsocaudally directed and tail cylindrical with a rounded end.
Ecology.- This species was collected in tuie sands (Qso = 0.24). with a \er\' good selection (Sq
= 0.73). The organic matter content was 0.51% and 4.61% of carbonates percentage.
Distribution.- East Atlantic Ocean (Piatt & Wanvick [12]). This species is first recorded in
the Canary Islands.
17
-n
Total body length 1342.9
a 31.3
b 30.3
c 15.9
Cephalic diameter 20
Cephalic setae 10
Amphid diameter 22.9
Amphid height 21
Amphid from anterior 7.1
Pharynx length 44.3
Pharynx cbd 32.9
Maximum body diameter 42.9
Spicule length
Gubemaculum length 47
s' 20
Tail length 1.3
Anal body diameter 84.3
c' 36
Spicule length/Tail length 2.3
Total body length 0.6
Table 4.-. Measurements of Soiithernia zosterae in |im.
Figure 4.- Soiithernia zosterae. A. Anterior end. B. Posterior end. Scale A = 25 |im, B = 32 [im.
18
Family Ceramonematidae Cobb, 1933
Ceramonema yunfengi Piatt & Zhang, 1982
(Fig. 5, Tab. 5)
Ceramonema yunfengi Piatt & Zhang [13]: 236, fig. 5; Piatt & Warwick [12]: 466, fig. 219.
Meristic data and studied material.- Abrigos subtidal: July, 1 female (^ 1), October, 1 female ( ^2).
Description.-
Female: Body slender, attenuating on both ends. Head slightly round, not set off and with a
cephalic capsule. Cuticle ornamented with transversal ridges, lateral differentiation lacking.
Amphids are 30% of the corresponding body diameter in width, "U-inverted" shape, located
at 16 |im from the anterior end. Buccal cavity and inner labial setae absent. 6 outer labial setae
0.7 cephalic diameters long and 4 cephalic setae 0.8 cephalic diameters long, situated in the
media part of the head capsule. Subcephalic setae lacking. Pharynx slender and cylindrical.
Reproductive system not discernible. Vulva located at the level of the 38% of the total body
length. Tail 3.8-5.4 anal diameters long, slender and cylindrical, with conical posterior tip.
Caudal setae absent. Spinneret poorly developed.
x\ ^2
Total body length 1200 1671.4
a 28 34.9
b 10.2 12.8
c 6.2 12.2
Cephalic diameter 23 35.7
Inner labial setae 17.1 21.4
Cephalic setae 11.9 12.9
Subcephalic setae 14.6 15
Amphid diameter 7.1 10
Amphid height 11.4 10.7
Amphid from anterior 15.7 14.3
Pharynx length - 14.3
Pharynx cbd 117.9 130.7
Maximum body diameter 39.3 28.9
Vulva from anterior 42.9 47.8
%V 457.1 nd
Spicule length 38.1 nd
Tail length
Anal body diameter 192.9 137.1
c' 35.7 35.4
Spicule length/Tail length 5.4 3.8
Table 5.- Measurements oi Ceramonema yunfengi in |.im; nd= no discernible.
19
Discussion.- This species is characterized by having amphids "U-inverted" shape, cuticular
ornamentation formed by ridges, and by the outer labial and cephalic setae arrangement. Ca-narian
specimens have a De Man index (a= 28-35) shorter than british individuls (a=54-78),
and females tail length (4-5 anal diameters long) are less developed than british ones (11-12
anal diameters long) (Piatt & Zhang [13]).
Figure 5.- Ceramonema yiinfengi. Male. A. Anterior end. B. Posterior end. Scale = 12 fim.
Ecology.- This species was recorded in median sands (Q50 = 0.24), with a very good seclec-tion
(Sq = 0.73-0.75). The organic matter content ranged from 0.51% to 0.78% and carbon-ates
percentage varied between 4.61% and 5.47%.
Distribution.- East Atlantic (Piatt & Zhang [13]). This species is first recorded in the Canary
Islands.
Dasynemoides sp.
(Fig. 6, Tab. 6)
Meristic data and studied material.- Tenerife, Cristianos subtidal: October 2000, 1 female ($1).
Description.-
Female: Body slender, tappering towards both ends. Head round, slightly set off, with a cephalic
capsule. Cuticle ornamented with transveral striations. Amphids 40% of the corresponding
body diameter in width, unispiral and located at 10 fim from the anterior end. Buccal cavity and
inner labial setae lacking. Six outer labial setae, 1 . 1 cephalic diameters long. Four cephalic
setae, 1.6 head diameters long, situated in the median part of the cephalic capsule. Subcephalic
setae absent. Pharynx slender and cylindrical. Ventral gland and nerve ring not seen.
20
The reproductive system is diorchic
with two reflexed ovaries. Vulva located
at the level of 56% of the total body length.
Tail 5.5 anal diameters long, cylindrical,
with round posterior end. Caudal setae ab-sent.
Spinneret poorly developed.
Discussion.- The studied specimen re-sembles
Dasynemoides alhaensis (War-wick
& Piatt, 1973) in total body length
and the arrangement of outer labial and
cephalic setae as well as in amphid size
and shape. However, females of D. al-baensis
present a larger and more cuticu-larized
cephalic capsule. Canarian
specimen was determined to genus level
due to former reasons and due to the lack
of males in good conditions.
Ecology.- This species was collected in
fine sands (Q50 = 0. 1 6), with a very good
selection (Sq = 0.58). The organic matter
percentage was 0.67% and carbonates
content was 24.52%.
1
Tola! body length 1385.7
a 35.3
b 10.2
c 15.7
Cephalic diameter 11
Outer labial setae 12
Cephalic setae 18
Amphid diameter 5.7
Amphid height 10
Amphid from anterior 15.7
Pharynx length 135.7
Phar>nx cbd 32.1
Maximum body diameter 39.3
Vuh a from anterior 771.4
«/0 V 55.7
Tail length 88
Anal body diameter 16
c" 5.5
Spicule lengthTail length
Distribution.- This genus is
recorded in the Canarv Islands.
first
Table 6.- Measurements of Dasynemoides sp in fim.
Figure 6.- Dasynemoides sp. Female. A. Anterior end. B. Posterior end. Scale A = 15 \xm. B = 30 ^m.
21
Metadasynemella sp.
(Fig. 7, Tab. 7)
Meristic data and studied material.- Tenerife, Abrigos intertidal: november 2000, 1 female ($1); Cris-tianos
subtidal: february 2001, 1 female ($2).
Description.-
Female: Body slender, tappering towards posterior end. Head not round, not set off with a de-veloped
cephalic capsule. Cuticle ornamented with transversal striations. Amphids are 24%
of the corresponding body diameter, round and simple, located at 14 |im from the anterior
end. Buccal cavity and inner labial setae absent. Outer labial and cephalic setae situated in the
same level. Outer labial setae 0.6 cephalic diameters long and 4 cephalic setae 0.2 cephalic
diameters long, located at the anterior part of the head capsule. Subcephalic setae lacking.
Pharynx slender and cylindrical. Ventral gland and nerve ring not seen.
Reproductive system and vulva not discernible. Tail 4.6 anal diameters long, cylindri-cal
with acuminated posterior tip. Caudal setae absent. Spinneret poorly developed.
$1 $2
Total body length 1757.1 1857.1
a 43.8 43.3
b 12.6 14.9
c 14.9 13.7
Cephalic diameter 22.9 24.6
Cephalic setae 13.8 14.3
Subcephalic setae 6 5.7
Amphid height 10 11.4
Amphid from anterior 11 10
Pharynx length 14 14.5
Pharynx cbd 139.3 125
Maximum body diameter 39.3 35.7
Vulva from anterior 40.1 42.9
%V
Spicule length nd nd
Gubemaculum length nd nd
s
Tail length
Anal body diameter 117.9 135.7
c' 26.1 28.7
Spicule length/Tail length 4.5 4.7
Table 7.- Measurements of Metadasynemella sp in (im.
Discussion.- The studied specimens are closely related to Metadasynemella picrocephala
(Haspeslagh, 1973) in amphid shape and cephalic setae length. However, M. picrocephala
22
has a more cuticularised cephalic capsule and broaden transversal striations. The remaining
species of the genus are characterized by having shorter cephalic setae (< 0.5 head diameters
long) and amphids ''U-inverted" shape. Canarian specimen has been determined to genus
level due to the lack of males.
Ecology.- This species was recorded in the intertidal of Los Abrigos in medium sands (O5,,
=
0.38), with a very good selection (Sq = 0.87). The organic matter content was 1.07% and
5.12% of carbonates percentage. In the subtidal of Los Cristianos was recorded in fine sands
(Q50 ^ 0.18), with a very good selection (Sq = 0.73). The organic matter content was 0.33%
and 23.08% of carbonates percentage.
Distribution.- This senus is first recorded in the Canarv Islands.
Figure 7.- Metadasynemella sp. Female. A. Anterior end. B. Posterior end. Scale A = 20 |.im. B = 25 \xm.
ACKNOWLEDGEMENTS
The first author (R.R.) thanks P.J. Somerfield (Plymouth Marine Laboratory. UK) for
taxonomical advice during the beginning of his research on free-living marine nematodes.
Authors also acknowledge Dr. Catalina Pastor de Ward (Centro Nacional Patagonico, Ar-gentina)
for interchange of ideas and encouragement.
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