First Data of Iberian Nematomorpha, with Redescription of Gordius Aquaticus Linnaeus, G. Plicatulus Heinze, Gordionus Wolterstorffii (Camerano) and Paragordius Tricuspidatus (Dufour)
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Contributions to Zoology, 70 (2) 73-84 (2001) SPB Academic Publishing hv, The Hague First data of Iberian Nematomorpha, with redescription of Gordius aquaticus Linnaeus, G. plicatulus Heinze, Gordionus wolterstorffii (Camerano) and Paragordius 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, taxonomy, 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, Gordius aquaticus 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 Downloaded from Brill.com10/05/2021 06:12:16AM via free access 74 L. C. de Villalobos, I. Ribera & D. T. Bilton - Iberian Nematomorpha 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. Downloaded from Brill.com10/05/2021 06:12:16AM via free access - Contributions to Zoology, 70 (2) 2001 75 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- Downloaded from Brill.com10/05/2021 06:12:16AM via free access 76 L. C. de Villalobos, I. Ribera & D. T. Bilton - Iberian Nematomorpha 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.