Contributions to Zoology, 70 (2) 73-84 (2001)

SPB Academic Publishing hv, The Hague

First data of Iberian , with redescription of aquaticus Linnaeus, G. plicatulus Heinze, wolterstorffii

(Camerano) and tricuspidatus (Dufour)

¹ Leonor+Cristina de Villalobos Ignacio Ribera² & David+T. Bilton³

1 Facultad de Ciencias Naturales y Museo, Universidad National de La Plata, 1900 La Plata, Argentina;

2 3 Department ofEntomology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK; De-

& partment of Biological Sciences Plymouth Environmental Research Centre (PERC), University of Ply-

mouth, Drake Circus, Plymouth PL4 8AA, UK

Keywords: Nematomorpha, Gordiidae, Gordius, Gordionus, Paragordius, parasites, , Spain

Abstract speciosus (Janda, 1894), considered to be of a

dubious taxonomic status by Schmidt-Rhaesa

from Galizia Four species of Nematomorpha are recorded from NE Spain, (1997), was described (Poland), and

the first reliable data the in the Iberian representing on group its inclusion in Iberia must be a confusion with

peninsula. Gordius aquations Linnaeus, 1758, G. plicatulus the Spanish Galicia. The Iberian records of Gordius Heinze, 1937, Gordionus wolterstorffii (Camerano, 1888) and pioltii Camerano, 1887, Parachordodes tolosanus Paragordius tricuspidatus (Dufour, 1828) are redescribed based (Dujardin, 1842), and Gordionus violaceus (Baird, on scanning electron microscope observations. Notes on 1853) were not considered by Schmidt-Rhaesa intraspecific morphological variation and ecology of the spe- cies in his of are given. (1997) recent revision the European fauna

of Nematomorpha, which included only Parachor-

dodes gemmatus (Villot, 1885), recorded from the Contents French Pyrenees. Other records are generic (e.g.

Gordionus spp. From Portugal, Schmidt-Rhaesa, Abstract 73 1997), or have no reliability (e.g. Codina, 1925). Introduction 73 Recent of adults of Nemato- Material and methods 73 captures free-living in Systematics 74 morpha NE Spain by the junior authors allowed

Gordius aquations 75 detailed study, for the first time, of Iberian repre-

Gordius plicatulus 76 sentatives of this interesting group. Four species Gordionus wolterstorffii 79 of Gordiidae are redescribed, Paragordius tricuspidatus 82 Linnaeus, 1758, G. plicatulus Heinze, 1937, Gor- Acknowledgements 84 dionus and References 84 wolterstorffii (Camerano, 1888) Para-

gordius tricuspidatus (Dufour, 1828). Males of G.

plicatulus are described for the first time, and the Introduction redescription of G. plicatulus, G. wolterstorffii and

P. tricuspidatus includes also for the first time of the in the Knowledge phylum Nematomorpha scanning electron microscope observations. Some Iberian and in the southern Mediterra- and peninsula, comments on the ecology intraspecific vari-

nean area in is still limited. In included. general, extremely ability of the species are Gerlach’s (1978) checklist five species are recorded b'om the Iberian peninsula south of the Pyrenees,

and Material and methods one from the Pyrenean area. Of these, Gordius

angulatus Linstow, 1906 should be excluded be-

cause All collected in their free, adult it was described from Madeira, not from specimens were post-parasitic

stage, and preserved in 70% ethanol. Fragments of cuticle from continental Portugal. Similarly, Parachordodes

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for the medial part ofthe body were extracted from specimens Systematics

light microscopy. Cuticle fragments were washed in lactophenol

for 24 hours, mounted and observed with a Wild Mka 2 Phylum Nematomorpha microscope aftercleaning and removing the remains ofmuscular Gordiidae tissue. For the study with scanning electron microscopy (SEM) Family Genus Gordius 1758 fragments of the specimens (mid-body, posterior and anterior Linnaeus,

ethanol end) were dehydrated in a series of increasing

concentrations,critical dried, mounted, coated, point gold-argon Linnaeus (1758: 647)

and observed and photographed with a Jeol SLM 1000 SEM.

All specimens were studied with both SEM and lightmicroscope.

Specimens studied are deposited in the Facultad de Ciencias G. Linnaeus, 1758 Naturales Museo the Natural Museum Type species aquaticus y (La Plata), History

(London) and the authors’ collections (see Table 1 for the

ofthe depository specimens). The genus Gordius is characterised by the presence

of a postcloacal crescent, anterior end acuminated,

posterior end round in females and with two lobes

in males, and cuticular areoles flat or absent

(Schmidt-Rhaesa, 1997). It has about 70 described

I. Gordius male. terminal lobes and of terminal Fig. aquations, A, postcloacal crescent; B, apex the lobes; C, cuticle, b, bristles; co,

cloacal I, tubercle. A= 1.000 B= 100 10 opening; lobes; pc, postcloacal crescent; t, Scale bar of pm; pm, C= pm.

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them have Table I. and of the species, although a large number of an Dimensions, locality depository specimens studied (see Table 2 for descriptions ofthe localities). FCNM, uncertain taxonomic status.

Ciencias Naturales Museo The Facultad de y (La Plata); NF1M,

Natural Flistory Museum (London); DEC, David Bilton collection Gordius aquations Linnaeus (Plymouth). (Fig. 1) Sex Length Maximum Locality Depository

(mm) Diameter (mm)

- in 75 Diagnosis. Dimensions as table 1, from to

987 colour mm. Male: body uniform pale brown Gordius aquaticus

Female 83 0.56 1 NHM (the specimens studied had no pale spots or dark FemaleFemale 987 1.1 4 FCNM in ring behind the calotte, but see comments Female 119 0.700.70 4 FCNM Schmidt-Rhaesa, 1997). Anterior end acuminate, FemaleFemale 115 0.650.65 9 FCNM with subterminal mouth Cloacal opening. opening Female 112112 0.61 99 FCNM

oval. Postcloacal crescent with a total length from Female 117 0.65 99 FCNM

62.2 and maximum width from 12.5 Male 350 0.79 44 FCNM to 723.3 pm, a

Male 75 0.49 9 NHM to 87.0 in the studied. Posterior lobes pm specimens Male 244 0.80 9 DECDBC short and broad, between 42.3 x 33 and 400 x 73.3 Male 420 0.95 9 DECDBC pm (Fig. 1A); apex round, with sparse spiniform

15 in the inner area of the lobe, processes pm long Gordius plicatulus

0.82 4 FCNM no bristles or other spiniform structures on the lateral Male 265 0.82 4 FCNM

Male 465 0.94 4 NHM sides of the lobes (Fig. IB). Cuticle smooth, only Male 480480 1.09 4 FCNM marked with fine subcuticular lines (Fig. 1C), with FemaleFemale 810 0.93 2 FCNM scattered acuminate tubercles no higher than 5.3 FemaleFemale 270 0.870,87 4 NHM

pm. Female 268 0.63 4 FCNM

Female: anterior end acuminate. Posterior end Female 164 0.67 4 FCNM

Female 267 0.79 5 FCNM not bilobed, with a central cloacal opening. Cuticle Female 164 0.61 5 FCNM as in males. See tables 1 and 2 for the material Female 920 1.72 6 FCNM studied. Female 270 0.72 7 FCNM

Remarks. - The Iberian specimens of G. aquaticus Gordionus wolterstorffii

differ de- Male 40 0.510.51 3 NHM in some characters with respect to the

scription given in Schmidt-Rhaesa (1997) (e.g. Paragordius trimtricuspidalusspidatus cloacal opening not round, with some tubercles and Male 117 0.81 8 NHM bristles on the tail lobes, only visible using SEM,

Fig. IB). We consider these differences attribut- able to incomplete descriptions or to intraspecific ferences between the measured males and females

variation. The of our as G. measured with two-tailed > identity specimens (as a t-Studcnt, p 0.5). smooth aquaticus was established based on the The species is distributed in western and central cuticle and char- the type of post-cloacal crescent, Europe (excluding UK) (Schmidt-Rhaesa, 1997). acters which present a higher constancy.

There is variation the a strong length among Ecological notes. - Most of the specimens were specimens from studied, even among specimens collected either in ponds in a mountain pasture (with the It if same locality (Table 2). is unknown this small streams nearby) (locality 4) or in a mountain

variation in corresponds to differences the host or stream (locality 9), on different types of substratum to other environmental factors or genetic (although and vegetation (Table 2). Known hosts include large previous studies that there is correla- suggest no species of Dytiscidae and Carabidae (Coleoptera) tion between the size of the host and the length of (Schmidt-Rhaesa, 1997). the parasite, Schmidt-Rhaesa, 1997; de Villalobos ct ah, 1999). There are no significant length dif-

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Table 2. Description of the localities in which specimens ofNematomorpha were found.

No. Station

11 Province of Barcelona, Cakies de Montbui, 2.12.1984,1. Ribera & J, I.I. Checa leg. Small stream onon a substratum of coarsesandsand

and and pebbles, no aquatic vegetation.vegetation.

2 Province of del Torrente Ribera Small in 30 2 Province Barcelona, Montseny, Turo Home, Torrente Castella, 23.8.1988,1. leg. Small pond in openopen area, ca. 30

diameter, Beech forest with abundant litter, substratum of sand and stones. cm diameter, 2 cmcm depth.depth. Beech forest with abundant litter, substratum of litter, sand and stones. 33

Province of Val d’Aran, river Pallaresa,2.7.1989,1, Ribera Lateral ca. m diameter and Province of Lleida, Val d’Aran, Montgarri, river Noguera Pallaresa,2.7.1989,1. leg. Lateral pond ca. 2 m diameterand

15 cm depth, connected to the main river.river. Substratum of silt and fine detritus,detritus. pH 8,0, conductivity 110 pS.

4 Province of Lleida, Val d’Aran, Pla de Beret, 24.9.1988,1. Ribera leg. Ponds in pasture, near the source of the rivers Garona

- - and Noguera Pallaresa, 1800-19001800-1900 m. a.s.l., pH 7.7 - 12.4;12.4; conductivityconductivity 130130 - 320 pS, substratum of silt with fine detritus,

with or without vegetation, visited by cattle.

55 Province ofGirona, Riera de Torrefies,Torrelles, 10.9.1994,1.Ribera & P.P. Aguilera leg. Residual pondpond in temporarytemporary river,river, ca, 5 x 3 m,

anoxic water black 30 cm depth. Substratum of coarse sand, with macrophytes, with anoxic water andand black silt.silt,

6 Province of Huesca, river Esera, 10.9.1988,1. Ribera Lateral at ca. 10 m of the main channel, 10 xx 6 Huesca, Benasque, Esera, 10.9.1988,1. leg. pond ca. 10 m the main channel, 10 2 m,

20 cm depth. Substratum of silt with some stones.

77 Province ofHuesca, Sabifianigo,Sabihanigo, river Guarga, La Calama,Calama, 14.5.1995, I.1. Ribera & P. Aguilera leg. Slightly running water,

shallow - shallow pools over stones and gravel, 5 15 cm depth. With filamentous algae.algae, pH 7.0. (remains of 1 ex.).

88 Province of Burgos, river Arlazon, south of Pineda dede la Sierra, Sierra de la Demanda. 22.07.1998, I. Ribera leg.leg. Mountain

stream, ca. 5 m wide, subtratumof pebbles and sand.

9 of of 1000m S ofPineda de Sierra de lala Demanda. D. Bilton Province Burgos, tributary ofriver Arlazon, ca. belowpass la Sierra, D.

leg. Small mountain stream with gravel in the margins, partly shaded by Quercus trees.

Gordins plicatulus Heinze with poorly definededges, perpendicular to the body

with (Figs. 2, 3) axis, a length from 10.7 to 11.5 pm, and a

from of height 7.3 to 11.25 pm. In some parts the

Heinze (1937: 326) cuticle these denticles are irregularly arranged, but

in the medial region (Fig. 2D) they are more or

Diagnosis. - Dimensions as in table 1, from 164 less regular. Among the areoles there are scattered 920 to mm. Male: anterior acuminate, white, tubercles with round 8.7 apex apices, pm height (Figs. in bordered by a dark collar. Mouth opening a 2D, E).

terminal Posterior end bilobed 2A), position. (Fig. Anterior apex of females acuminate, with a dark cloacal opening oval with short circumcloacal collar behind the calotte. Mouth opening in sub- bristles (3.6 2A, Postcloacal pm height) (Figs B). terminal position. Posterior end not bilobed, round

crescent ca. half the parabolic, elongated, length (Fig. 3A). Cloacal opening round, in a medial of the with total and width of each lobe, a length depression. When observed with light microscope, of the sides varying (in the specimens studied) the cuticle similar to that of males. With appears between 22 * 5.5 and 40 x l() and a maximum the pm, SEM cuticular foldings appear narrower and

width to ca. 10 Lobes with a from up pm. length more protruding, like denticles, and more densely

57.7 to 90.0 and maximum width from 24.3 pm a arranged than in males (Fig. 3B).

to 38.0 pm. The apex of the lobes forms a spoon

in which small bristles - shaped cavity, very (1.9 Remarks. The species was described with females

can be observed of the males pm) (Fig. 2A). One from Freiburg, Tuttlingen and Darmstadt in Ger- had a spermatic cord (or drop) 154 long and later sperm pm many (Fleinze, 1937), recorded by (Figs 2B, C). Canadjija (1956) from Zagreb, in Croatia, who also

Cuticle with small, narrow and scat- irregularly provided a (incomplete) description of males. There tered cuticular projections, in a trans- generally are no further records of the species, and the hosts

verse orientation with to the axis. respect body are unknown. As with happened in the previous Under SEM 2D, E) these variation (Figs. projections ap- species, there is a large in size of un- pear as denticles or thin cuticular very foldings, known origin, but no significant differences in

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2. Fig- Gordius male. terminal lobes cloacal with the detail of plicatulus, A, and postcloacal'trescent; B, opening, sperm drop; C, the

sperm D, cuticle with transverse detail of the cuticular and tubercles, b, cloacal drop; foldings; E, foldings bristles; co, opening; cs,

circumcloacal lobes; crescent; sd, cuticlar folds; tubercles. Scale bars ofA= 500 B and spines; 1, pc, postcloacal sperm drop; sf, t, pm; D= 100 C and E= 10 pm; pm.

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3. Gordius female. cuticle the and like in Fig. plicatulus, A, posterior apex; B, (note narrower more densely packed folds, denticles,

= 100 comparison to those of the males, Fig. 2E). co, cloacalopening. Scale bars pm.

males and females. The of as this is the first time length among identity ticularly interesting, they

noted our specimens was established based on the origi- are for a species of the genus Gordius.

nal description, which included enough detail to allow an unequivocal identification. Ecological notes. - All the specimens were found

Gordius plicatulus seems to be most similar to in small pools associated with mountain rivers or

G. tirolensis Heinze, 1937. In this species the cu- streams, or directly in the streams (Table 2).

ticle has elevated structures of different shapes,

transversely arranged with respect to the body axis.

However, in G. tirolensis these structures are wider Genus Gordionus Muller and The lobes of the male Gordius violaceus Baird more sparse. apical are Type species (1853: 36) also shorter, and only 1/4 longer than wider, in

comparison to that of G. plicatulus. Muller (1927: 198- 199)

According to the original description by Heinze

Diagnosis. - Anterior end not (1937, 1941) the cuticle of G. plicatulus would usually tapered. Mouth terminal subterminal. Posterior not have true areoles, but small short foldings opening or end of the males with lobes tranverse to the body axis, irregularly arranged two usually longer

through the body surface. Our observations with than wide. Cloacal opening rounded, with or without

the circumcloacal bristles; with two light microscope agree with this description, precloacal both for bristleficlds formed males and females. The dorsal and ven- by long, linearly arranged

tral line bristles short and mentioned by Heinze (1937) could not be bristles; postcloacal pointed. observed. Females with round Cuticle with apex. a single

The of circumcloacal bristles of areoles, either flat or presence is par- type protruding, poorly

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of with delimited in some species because the fusion of in the interareolar furrows, an irregular rect-

from width the anterior and posterior margins (e.g. in G. angular shape (length 20.5 to 23.3 pm,

strigatus Muller, 1927). Usually with spiniform from 7 to 14 pm) (although in the posterior end of

structures in the interareolar sulcus. the body they also form longitudinally arranged

strings in which the anterior and posterior limit of

Remarks. - of males of each individual areole difficult The posterior apex are to distinguish).

Gordionus is similar that of the of In the extreme of the ventro-lateral very to species posterior area

Parachordodes, but the structure of the cuticle is (Figs 4F, G) there are oval structures (“lateral

clearly different: species of Parachordodes have blumps” according to Cham et ah, 1983; “adhesive

in the of two well defined types of areoles, one moderately warts” more recent terminology Schmidt-

and the second with central in a distance about mm an- protruding large a pore. Rhaesa, press), at 0,6

These two types of areoles are found through the terior to the cloacal openning. These structures

body surface, without modifications in the ventral become larger, oval, longitudinally aligned, and

lateral with in the interareolar or areas. depressions spaces (as

observed with SEM), with length from 17.6 to 26.5

pm and width from 4.0 to 6.2 pm. They are sur-

Gordionus wolterstorffii (Camerano, 1888) rounded by a deep sulcus, and usually occur in

(Fig. 4) pairs, alternate or aligned (but not contiguous), with

spiniform structures between them.

Camerano (1888: 6)

Gordius pleskei Camerano (1896) Remarks. - Although the the species of Gordionus Parachordodes wolterstorffii Camerano (1897) have only one type of areoles, Gordionus wolter- Parachordodespleskei Camerano (1904) has transitional in the Gordionus storffii some changes type wolterstorffii Heinze (1937)

of areoles across different regions of the body

(without defining clear - 1. Diagnosis. Dimensions as in table Body pale types). It is interesting to note the different interpreta- brown. Anterior end pointed (Fig. 4A). Posterior tion of the granulated structures of the areoles. end bilobed, with lobes (in the studied specimen)

Camerano and Cham et al. note a 413 146 wide Precloacal (1888) (1983) pm long and pm (Fig. 4B). large of these structures in the area (Fig. 4C) with bristle fields formed by long quantity granulated

interareolar depressions on most of the cuticle. setae (some of them bifurcated). The bristle fields

do According to our observations with the light mi- not join above the cloacal opening. Cloacal in croscope, the cuticle the dorsal region seemed opening oval, surrounded by short and sparse

to have elevated criss- circumcloacal bristles; distance between cloacal long ridges separated by

lobes Area crossing rows with granules. When observed with opening and the base of the 60 pm.

they as areoles with defined Posterior to the cloacal opening and internal side SEM, appeared poorly

of with lateral instead of the lobes to the middle of their with edges, projections granules up length be discarded the that the numerous 13 (it cannot possibility bristles with acuminate apices, pm observed areoles transition form ventral 'ong (Figs 4D, E). were a to

what to be in the Areoles of the cuticle with some variations de- areoles). Similarly, appear pores

be between flat areoles proved to a con- pending on the region of the body (as seen with spaces light tinuous sulcus them. In the ventral side microscope), some large andothers shallower, surrounding

v flat the interareolar have both lateral projec- ery in appearance, with or without defined spaces

edges. In tions and small seta, more like granules. We the dorsal region (Fig. 4H) the flat ar- very eoles fuse thus with Cham et al. (1983) in the observa- to form long strings, with almost indis- agree hnguishable tion of differences in the structure of the areoles limits between them, and separated by in different of the very irregular interareolar furrows. In the ven- parts body.

tral the cuticular areoles The apex of Gordionus region (Figs 4F, G) are posterior wolterstorffii

better has the same general structure as that of G. defined, with granules and rounded apex setae

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4. Gordionus male. A, anterior B, bristles or bristle fields (note the bifurcated Fig. wolterstorffii, apex; posterior apex; C, precloacal

of some of internal side ofthe terminal lobes with cloacal interareolar apex them); D, postcloacal spines, co, opening; if, furrow; mg,

adhesive “lateral Scale bars warts (or blumps”); me, areoles; 1, lobes; p, pores; pb, precloacal bristles; ps, postcloacal spines; s, spines.

ofA= 500 F and G= 100 E= 10 H= 20 pm; B, C, D, pm; pm; pm.

violaceus, G. linourgos de Villalobos, Ribera & and the cuticle is covered with transversal striae;

Downie, 1999 and G. diligens de Villalobos, Ribera and G. diligens has round areoles connected be-

& Downie, 1999 (de Villalobos et al., 1999), with tween them by cuticular projections crossing the bristle fields at the sides and anterior to the cloa- interareolar sulci.

The cal opening, and postcloacal spiniform structures species was previously recorded from Brit-

along the inner side ofthe terminal lobes. The cuticle ain, Belgium, north Italy and central Europe of all these species is, however, clearly different: (Schmidt-Rhaesa, 1997).

G. violaceus has well defined round and polygonal

with areoles, a large number of short hairs in the Ecological notes. - The single studied specimen

interareolar G has oval areoles found in with sulcus; linourgos was a marginal pond associated a

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rig- 4. Gordionus male. detail and wolterstorffii, E, ofthe postcloacal spines; F G, cuticle ofthe lateroventral area; H, cuticle ofthe dorsal area ofthe cloacal interareoiar furrow; adhesive warts “lateral body, co, opening; if, mg, (or blumps”); me, areoles; 1, lobes; p, pores; pb, precloacal bristles; Scale bars ofA= 500 B, C, D, F and G= 100 E= 10 Fl= 20 ps, postcloacal spines; s, spines. pm; pm; pm; pm.

mountain river (Table 2). Known from a number Diagnosis. - Anterior end distinctly tapered. Pos- of Colcoptera Carabidae hosts, mainly (Schmidt- terior apex of males bilobed, with long and narrow Rhaesa, 1997). lobes. Cloacal opening oval, withoutcircumcloacal

but with short spines or bristles, acute postcloacal

bristles covering also the inner side ofthe terminal Genus Paragordius Camerano lobes. Some species (e.g. the European P. tricuspi- Type Filaria species tricuspidata Dufour, 1828 datus (Dufour, 1828), and the American P. varius

(Leidy, 1851) and P. esavianus (Carvalho, 1942)) Camerano (1897: 400) have precloacal bristles extending anteriorly along

the longitudinal ventral sulcus. Posterior end of

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with females trilobed, terminal cloacal opening a central depression, surface covered with tubercles

the lobes. Cuticle similar in both with 3.3 with the of among sexes, pm height, appearance scales, ar-

poorly defined, shallow areoles. ranged transversely with respect to the body axes.

Interareolar spaces with pores of different sizes

(from 3.7 to 11.8 pm), surrounded by a cuticular

rim formed circular fibres and Paragordius tricuspidatus (Dufour, 1828) by very scarce tu-

(Fig- 5) bercles with an acute apex. Cuticle covering the

terminal lobes with a different structure, with less

Filaria Dufour (1828: tricuspidata 228) well defined areoles and a smoother, more homo- “Dragonneau de Claix” Charvet (1834) geneous appearance (Fig. 5D). Gordius tricuspidatus Meissner (1856)

Gordius gratianopolensis Schneider (1866) Remarks. - The of the Gordius trilobus Villot (1874) placement European spe- cies of is Paragordius tricuspidatus Camerano (1897) Paragordius controversial, as already

noted Schmidt-Rhaesa (1997), partly due to the

Diagnosis. - Dimensions as in Table 1. Male: body lack of detail in the original descriptions, which

colour dark brown, with an evident longitudinal were all based on observations with light micro-

ventral - which in sulcus, particularly at the posterior apex scope are agreement with our observa-

Medial sulcus well defined tions 1 in with (Fig. 5A). longitudinal (see e.g. Fig. Camerano, 1887, groups

on the posteroventral side, flanked with compact of areoles forming lines or clusters). However, as

lines of bristles in its apical third; central and an- seen above, the details of the structure appear very

terior parts of the body with less well developed different when studied with SEM.

The ventral sulcus, with no marginal bristles (Fig. 5E). two European species, P. tricuspidatus and

Dorsal sulcus not evident. White calotte, bordered P. stylosus (Linstow, 1883), were considered to

a darker on the anterior Mouth be Camerano and Dorier by collar, apex. synonyms by (1897)

subterminal. Posterior On the Heinze apex bilobed, with two very (1930). contrary, (1941) noted clear

lobes and differences in the end of the with long cylindrical (533 pm long 166 pm posterior males,

wide in the specimen studied) (Fig. 5A). Cloacal P. stylosus lacking precloacal bristles but with

58.6 x 27.5 in in the opening oval, dimensions pm the numerous spines postcloacal region extend-

specimen studied, without circumcloacal bristles, ing to the ventral side of the terminal lobes, while

surroundedby smooth cuticle (Fig. 5B). Small (7.4 P. tricuspidatus has lines of bristles flanking the

pm) conical adhesive warts, regularly aligned, cloacal opening, extending anteriorly and posterior-

extending anteriorly for approximately 40 mm at ly on the internal side of the terminal lobes, as both sides of the ventral sulcus (Fig. 5A). Sparse well as postcloacal bristles. The cuticle is similar

bristles in both acute extending towards the apex of the species, although P. stylosus does not have

lobes their inner side on (Figs. 5A, B). pores.

As observed with the light microscope, cuticle These differences allow us to identify the speci-

P. apparently not totally covered with areoles, which men studied as tricuspidatus, although more

studies are arranged in small groups of 8 to 10, sometimes on the taxonomic status of European

Interareolar in linearly disposed. space granulated, Paragordius are clearly needed, particular SEM with a with round of the cuticle of very irregular surface, pores. study P. stylosus.

Short and broad tubercles on the surface of the Dorier (1930) considered P. varius (so far re-

which corded from areoles, are in general polygonal and irregular only America, see e.g. Leidy, 1851;

(some of them appear round). Montgomery, 1898, 1903; May, 1919; Carvalho

When observed with SEM the cuticle has Miralles & de Villalobos de Villalobos a very 1942; 1993; different appearance: areoles not well defined, et al., 2000) to be a synonym of P. tricuspidatus. forming irregular elevations of the cuticle with However, the cuticle of both species is clearly

from 15.8 to with length 21.6 pm, and width from 8.3 different, P. varius having bristles and pores to 12.5 of the in the areoles and in the interareolar pm (Figs. 5C, E). Many areoles with spaces, and

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F‘S- 5. Paragordius tricuspidatus, male. A, posterior end; B, cloaca.l opening, with precloacal and postcloaca! bristles; C, cuticle of

■dorsal of defined ventral furrow, side the medial part of the body; D, terminal lobe, with poorly areoles; E, longitudinal a, areole; b,

britles; ventral furrow. Scale bars of co, cloacalopening; pb, precloacal bristles; p, porus; ps, postcloacalbristles; vf, A= 1,000 pm; B,

Band D= 100 C= 10 pm; pm.

Downloaded from Brill.com10/05/2021 06:12:16AM via free access 84 L.C. de Villalobos, I. Ribera & D.T. Bilton - Iberian Nematomorpha

form Codina 1925. El cas d’un Gordius (Venn.: cuticular rims which seem to stripes some- A. Nematoides)

extret del cos d’un Stauroderus (Orth.: Acrydiinae). Bull. times higher than the areoles themselves. This Inst, catal. Hist. nat. 25: 61-64. species also has well delimited ventral and dorsal Charvet 1834. du Nouv. M. Deux Especes genre Dragonneau. with numerous bristles longitudinal sulci, long Ann. Mus. Hist. Nat. Paris 3: 37-46.

the ventral sulcus its entire flanking along length. De Villalobos C, Ribera I, Downie S. 1999. Hairworms

The species has a predominantly south and cen- found in Scottish agricultural land, with descriptions of

two new species of Gordionus Muller (Nematomorpha: tral European distribution (France, Switzerland, Gordiidae). J. Nat. Hist. London 33: 1767- 1780, north Italy, Bulgaria, Rumania) (Schmidt-Rhaesa, De Villalobos C, Ramirez G, Chavarria S, Zanca F. 2000. 1997). Cuticular ultrastructure ofParagordius esavianus Carvalho

and P. varius (Leidy). Proc. Acad. Nat. Sci. Philadelphia

Ecological notes. - The single studied specimen 150: 135- 144.

Dorier A. 1930. Recherches biologiques et systematiques was collected in a mountain river among pebbles sur les Gordiaces, Trav. Lab. Hydrob. Pise. Univ. Grenoble and sand (Table 2). The hosts of the species are 22 anne; 1-183. not known with it is certainty, although suspected Dufour ML. 1828. Observations nouvelle de sur une espece

to be on du parasitic (Schmidt-Rhaesa, vers genre Filaria. Ann. Sc. Nat. Se.l 14: 228.

1997). Gerlach SA. 1978. Nematomorpha. In lilies J. (ed.) Limno-

Gustav 50-53. fauna Europaea. Sttutgart: Fischer, pp

Heinze K. 1937, Die Saitenwiirmer () Deutschlands.

Acknowledgements Eine systematisch-faunistische Studie iiber Insektenparasiten

aus der Gruppe der Nematomorpha, Z. Parasitenk. 9: 263-

344. We thank the Electronic Microscope Service ofthe Museo de Heinze K. 1941. Saitenwiirmer oder Gordioidea (Nemato- la Plata(Argentina) for their help, and Andreas Schmidt-Rhaesa morpha). In Dahl F, ed. Die Tierwelt Deutschlands. Vol. and Iain Downie for their useful comments on the manuscript. 39.3. Jena: Gustav Fischer, 1-78.

Leidy J. 1851. On the Gordiaceae. Proc. Acad. Nat. Sci.

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