Paragordius is a genus of Gordiida with a worldwide distribution, but with a scarce specific diversity. Sixteen species of the genus Paragordius have been described so far. In many cases, as with the other genera of Gordiida, the original descriptions of the species are insufficient due to the limitations of the techniques employed. In this work the holotypes of P. minusculus and P. esavianus are redescribed by scanning electron microscopy (SEM), a new species of Paragordius is described, the distribution for P. esavianus and P. varius is enlarged and a new host record of P. esavianus is presented.Facultad de Ciencias Naturales y Muse

Villalobos, Leonor Cristina de

Zanca, Fernanda Mariel

Acta Parasitologica

English

El Servicio de Difusión de la Creación Intelectual

DOI: 10.2478/S11686-006-0034-4
© 2006 W. Stefa risk! Institute of Parasitology, PAS
Acta Parasitológica, 2006, 51(3), 217-222; ISSN 1230-2821 VERSITA
South American species of Paragordius Camerano, 1897 
(Gordiida, Nematomorpha), with redescription of Paragordius 
minusculus and a description of a new species
Fernanda Zanca1’2* and Cristina de Villalobos1’3
*Corresponding author: finzanca@fcnym.unlp.edu.ar
'Facultad de Ciencias Naturales y Museo, UNLP, Paseo del Bosque S/N, La Plata, "Consejo Nacional de Investigaciones Científicas y 
Técnicas, CONICET, "Comisión de Investigaciones Científicas, CIC: Argentina
Abstract
Paragordius is a genus of Gordiida with a worldwide distribution, but with a scarce specific diversity. Sixteen species of the 
genus Paragordius have been described so far. In many cases, as with the other genera of Gordiida, the original descriptions 
of the species are insufficient due to the limitations of the techniques employed. In this work the holotypes of P. minusculus 
and P. esavianus are redescribed by scanning electron microscopy (SEM), a new species of Paragordius is described, the dis­
tribution for P. esavianus and P varius is enlarged and a new host record of P. esavianus is presented.
Key words
Paragordius, Gordiida, Nematomorpha, SEM
Introduction
The Gordiida or hairworms have a worldwide distribution, 
inhabiting mainly tropical and subtropical areas. At present 19 
genera of freshwater nematomorphs are known (Zanca and 
Schmidt-Rhaesa 2006).
In spite of being one of those genera among Gordiida 
which have the widest worldwide distribution (together with 
Gordius, Gordionus and Chordodes), Paragordius has a 
scarce specific diversity. Sixteen species of the genus Para­
gordius have been described so far. Nine species are from Afri­
ca: P. areolatus Linstow, 1906; P. cinctus Linstow, 1906; P dar- 
tevellei Sciacchitano, 1958; P. flavescens Linstow, 1906; 
P. laurae Sciacchitano, 1958; P. marlieri Sciacchitano, 1958; 
P mulungensis Sciacchitano, 1958; P. somaliensis Sciacchi­
tano, 1962; P. tanganikensis Sciacchitano, 1958 (Linstow 1906; 
Sciacchitano 1958, 1962); two are from Europe: P. stylosus 
(Linstow, 1883); P. tricuspidatus (Dufour, 1828) (see Schmidt- 
Rhaesa 1997); two are from Asia: P. enteryi (Camerano, 1895) 
(Camerano 1895); P. stylosus Linstow, 1883 (Linstow 1883, 
Camerano 1915); one is from North America: P. varius (Lei- 
dy, 1851) (see Schmidt-Rhaesa et al. 2003); two are from 
Central America: P. diversolobatus Heinze, 1935; P. varius 
(Heinze 1935, Schmidt-Rhaesa and Menzel 2005); and four 
species are known for South America: P. esavianus (Carvalho 
1942, de Villalobos et al. 2000); P. flavescens Linstow, 1906 
(Linstow 1906); P. minusculus Carvalho, 1944 (Carvalho 
1944) and P. varius (see Miralles and de Villalobos 1993, de 
Villalobos et al. 2000).
The genus Paragordius is characterized by a trilobed pos­
terior end in females and two long and narrow lobes in males. 
The cuticle varies between different species being able to 
form transverse irregular cords with knoblike structures on 
top (Schmidt-Rhaesa et al. 2003) or with poorly defined, shal­
low areoles (de Villalobos et al. 2001). Areoles are cuticular 
structures in compartments which may be flat, polygonal or 
more elevated and elaborated (Schmidt-Rhaesa 2002).
In many cases, as with the other Gordiida genera, the orig­
inal descriptions of the species are insufficient due to the lim­
itations of the techniques employed. In this work the holo­
types of P. minusculus and P. esavianus are redescribed by 
scanning electron microscope (SEM), a new species of Para­
gordius is described, the distribution for P. esavianus and/J var­
ius is enlarged and a new host record of P. esavianus is pre­
sented.
Materials and methods
We examined the holotypes of Paragordius minusculus (MNRJ 
container 118, in vial without accession number) and Para­
gordius esavianus (MNRJ container 118, in vial without ac­
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218 Fernanda Zanca and Cristina de Villalobos
cession number) deposited in Museu Nacional of Rio de Ja­
neiro. Brazil. Also, we investigated specimens of P. esavianus, 
P. varius and Paragordius sp. housed in the Museu Nacional 
of Rio de Janeiro. Brazil (MNRJ), the Museo de Ciencias 
Naturales de La Plata. Argentina (MLP), Fundación Miguel 
Lillio, Instituto de Zoología, Tucumán, Argentina (IML) and 
Facultad de Tecnología y Ciencias Aplicadas. Universidad Na­
cional de Catamarca (FTyCA). All the preserved specimens 
were fixed in ethanol.
Body measurements were made with outstretched worms 
using a ruler. Diameters were measured under dissecting mi­
croscope using a calliper ruler.
In order to preserve the holotype of P. minusculus and 
P. esavianus we removed a tangential section of the middle 
region of the body with a razor blade. The posterior ends of the 
above mentioned specimens were only investigated under 
light and stereomicroscope.
Specimens were dehydrated in an increasing ethanol se­
ries. critical point-dried, mounted on bronze blocks and gold 
sputter-coated. Observations were performed using a JEOL 
JSM 6360 LV scanning electron microscope. All preparations, 
i.e. SEM stubs, are stored together with the preserved speci­
mens in the respective museums.
Results
Paragordius minusculus Carvalho, 1944 (Fig. 1)
Description: Light brown body. 70 mm long and 0.5 lmn in 
diameter. Anterior end rounded with dark collar behind the 
white tip. The mouth opening terminal. The posterior end with 
two long and narrow lobes with postcloacal spines on the ven­
tral and inner side. The cloacal opening oval.
The cuticle of midbody (Fig. 1A-C) presents a velvet-like 
aspect as it is mostly covered by digit-like cuticular projec­
tions. like bristles, with blunt apex. These projections are dif­
ferent in height (1.3-3.2 pm) and are not uniformly distrib­
uted. In spite of the cuticle surface being fully covered with 
bristles in some sectors remnants of areole borders can be 
observed (Fig. 1C).
Holotype: Male.
Type locality: Viscosa, Minas Gerais, Brazil.
Host: Unknown.
Material investigated: Holotype (MNRJ vial 118, without 
accession number) (stereomicroscope, posterior end; SEM 
midbody).
Distribution: Viscosa. Minas Gerais. Brazil.
Remarks: Carvalho (1944), when describing the cuticle of
Fig. 1. Paragordius minusculus. A. General view of midbody cuticle. B. Detail of cuticle showing cuticular projections like bristles. 
C. Midbody cuticle showing rounded structures strange to the holotype. Scale bars = 50 pm (A), 5 pm (B), 100 pm (C)
Unauthenticated
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South American species of Paragordius 219
P. minusculus, points out the presence of conic projections and 
isolated areoles. Our SEM investigations allowed detailed 
description of the bristle-like projections distributed over the 
whole cuticle but the areoles mentioned by this author were 
not observed. It is possible that Carvalho (1944) when observ­
ing the cuticle at low optical resolution described those round­
ed structures scattered over most of the cuticle, which corre­
spond to foreign materials representing contamination of cuti­
cle surface of the holotype, as areoles (see Fig. 1 A, B).
Paragordius andreasii sp. nov. (Fig. 2)
Description: Body light brown, 134 lmn long and 0.8 mm in 
diameter. The anterior end rounded with terminal mouth and a 
dark neck behind the white tip. The posterior end (Fig. 2A) 
bilobed with 2 lateral lobes 263 pm long and 100 pm wide. 
The distance between the bifurcation of the lobes and the cloa- 
cal opening 129 pm. The cloacal opening rounded and devoid 
of circumcloacal bristles (Fig. 2A). The cuticle around the
Fig. 2. Paragordius andreasii sp. nov. A. Posterior end: c - cloacal opening; 1 - lobe. B. Ventral furrow with a pair of long rows of tuber­
cles. C. General view of midbody cuticle. D. Detail of lateral view of cuticle: d - depression, e - cuticular elevation, t - tubercle. Scale bars 
= 100 pm (A), 10 pm (B, C), 5 pm (D)
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220 Fernanda Zanca and Cristina de Villalobos
cloacal opening and in the internal surface of the lobes smooth 
with sharp conical spines reaching half of the lobes. The rest 
of the cuticle at the posterior end rough with abundant and 
small depressions very close to each other (Fig. 2A), being a 
modification of the cuticular pattern of the midregion of the 
body. Anterior to the cloacal opening and on both sides of the 
longitudinal ventral furrow pair of long rows of short single or 
ramified tubercles (Fig. 2A). The cuticle between the tuber­
cle rows structured by transversal cord-like folds (Fig. 2B).
The midbody cuticle shows oval or rounded depressions 
(4.1-6.7 pm in diameter), arranged in pairs or forming per­
pendicular lines to the axis of the body. The space between 
these depressions is generally wide (between 2.2 and 12.3 pm), 
with scattered cuticular blunt elevations and tubercles (3.4 pm 
long) (Fig. 2C, D).
Holotype: Male.
Type locality: Arroyo Piedra Blanca (32°19'00.8"S, 
65°00'18.4"W) Merlo, SanLuis, Argentina.
Host: Unknown.
Material investigated: Holotype (MLP 3573), (SEM pos­
terior end and midbody).
Distribution: San Luis, Merlo, Argentina.
Etymology: The name of this species is dedicated to Dr 
Andreas Schmidt-Rhaesa that is a great specialist in Nemato- 
morpha.
Remarks: The presence of oval or rounded depressions in 
the cuticle arranged in pairs or forming perpendicular lines to 
the axis of the body and generally separated by a wide space is 
unique and justifies the description of a new species.
Paragordius esavianus Carvalho, 1942 (Fig. 3A)
Description (holotype female): Body light brown, 211 mm 
long and 1 ímn in diameter. Anterior end pointed with a dark 
ring behind the calotte. The posterior end with three long 
lobes (155 pm). The ultrastructural characteristics of the cu­
ticle (Fig. 3 A) are the same as pointed out by de Villalobos et 
al. (2000) for specimens of this species.
Holotype: Female.
Type locality: Cachoeira do Itapemirim, Estado Espirito 
Santo, Brazil.
Host: Eidmanacris sp. (Orthoptera, Grylloidea) (new re­
cord) (MLP 5037).
Material investigated: Holotype (MNRJ vial 118, without 
accession number) (stereomicroscope, posterior; SEM mid­
body); 1 ? (MLP 5037) Cuña Pint river, Aristóbulo del Valle, 
Misiones, Argentina.
Distribution: Argentina: Salta: Arenales river. Department 
Capital (de Villalobos et al. 2000), Escoipe river (de Villalo­
bos et al. 2000); Misiones: Aristóbulo del Valle, Cuña Pin! 
river (new record). Brazil: Estado Espirito Santo, Cachoeira 
do Itapemirim (Carvalho 1942).
Paragordius varius (Leidy, 1851) (Fig. 3B)
Type locality: Philadelphia, U.S.A.
Host: Undetermined Grillydae (MNRJ container 118, vial 
No. 10) (new record).
Material investigated: 3d'd', 5? ? (MLP 5043) Córdoba, 
El Durazno; 1 ? (MLP 5040) Córdoba, Villa Rosas; 1 V (MLP
Fig. 3. General view of midbody cuticle. A. Paragordius esavianus holotype. B. Paragordius varius (MLP 5042). Scale bars = 20 uni (A), 
10 |im(B)
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South American species of Paragordius 221
3562), Córdoba, Cabana stream; lcf (MLP 3563) Córdoba, 
Mina Clavero; 1? (MLP 3565) Córdoba, Valle Hermoso, 
Villa Yacouna; lcT (MLP 3568) Córdoba, San Antonio river; 
1 ? (MLP 3570) Córdoba, Río Primero; 1 ? (MLP 3572) Men­
doza, Chacras de Coria; 1 specimen sex unknown (MLP 3569) 
Mendoza, Los Reyunos; 1 ? (MLP 3571) Mendoza, San Ra­
fael; lcf (MACNBR without collection number, 6/47) Mi­
siones, Cerro Azul; 1 ? (MLP 5042) Buenos Aires, Sierra de la 
Ventana, El Negro stream; lcf (MLP 5044) Buenos Aires, 
Sierra de la Ventana, El Loro stream; 1 cf (Museo de San Ni­
colás, without accession number) Buenos Aires, Ramallo; 
2? ? (MLP 5042) Río Negro, General Conesa; lcf (MLP 
5045) Río Negro, Villa Manzana; 1 ? (MLP 3566) Río Negro, 
Cipolletti; lcf (MLP 3560) Salta, Campo Quijano; 1? (MLP 
3564) San Luis, Merlo; lcf, 1 ? (IML 02441) Tucumán, Bur- 
ruyacu; lcf (IML 01514) Tucumán, Potrero de las Tablas; lcf 
(IML 00788) Salta, San Martin department, Campari river; I ? 
(FTyCA no accession number) Tres Puentes, del Valle river; 
3? ?, lcf (MNRJvial 118, No. 10), Minas Gerais, Patos; Id1 
(MNRJ vial 118, No. 29) Rio de Janeiro, Villa Seropédica.
South American distribution: Argentina: Buenos Aires: 
Ramallo (new record); Sierra de la Ventana: El Loro stream 
(new record). El Negro stream (new record). Córdoba: (Mi- 
ralles and de Villalobos 1993), El Durazno (de Villalobos et al. 
2000), Villa Rosas (new record). Cabana (new record), Mi­
na Clavero, San Lorenzo stream (new record); Villa Yacouna, 
Valle Hermoso (new record), San Antonio river (new record), 
Río Primero (new record). Catamarca: Tres Puentes, Del Valle 
river (new record). Jujuy: Unspecified location (Miralles 1969). 
Mendoza: Chacras de Coria (new record). Los Reyunos (new 
record), San Rafael (new record). Misiones: Cerro Azul (new 
record). Rio Negro: (Miralles and de Villalobos 1993), Gen­
eral Conesa, Villa Manzana (new record), Cipolletti (new re­
cord). San Luis: Unspecified location (Miralles and de Vil­
lalobos 1993), Merlo (new record). Salta: Unspecified loca­
tion (Miralles and de Villalobos 1993), Campo Quijano (new 
record), San Martin department, Campari river (new record). 
Tucumán: Unspecified location (Miralles 1969), Burruyacu 
(new record), Potrero de las Tablas (new record). Brazil: Mi­
nas Gerais, Patos (new record). Rio de Janeiro, Villa Seropé­
dica (new record).
Remarks: The characteristics of the posterior end and cuti­
cle in males and females are coincident with the redescription 
carried out by de Villalobos et al. (2000) (see Fig. 3B).
Discussion
The South American species of Paragordius studied have 
characteristics of their own at the cuticle level which make 
them valid species. The cuticle of P. minusculus is covered by 
digit-like cuticular projections producing a velvet-like aspect. 
In P. esavianus the cuticular surface has small cuticular ele­
vations, round tubercles perpendicular to the axis of the body 
and some long bristles. P. varius has irregular areoles with a 
central tubercle or a central pore, arranged perpendicularly to 
the axis of the body and cuticular rims between the areoles. In 
P. andreasii sp. nov. oval or rounded depressions are present 
generally arranged in pairs or forming lines perpendicular to 
the axis of the body generally separated by a wide furrow. The 
most widely distributed species of the genus Paragordius is 
P. varius. with registers in Europe (Schmidt-Rhaesa 1997), 
Central and North America (Schmidt-Rhaesa et al. 2003, 
Schmidt-Rhaesa and Melzer 2005) and South America (de 
Villalobos et al. 2000). P. esavianus, P. minusculus and P. an­
dreasii sp. nov. is found only in South America. The distribu­
tion ofP. flavescens is doubtful. This species was described by 
Linstow (1906) from two females, one of them from Tucumán 
(Argentina) and the other from Costa Rica. Camerano (1915) 
considers the description as insufficient and assumes an even­
tual correspondence with P. varius and defines it as an “uncer­
tain species”. Heinze (1935) studies Linstow’s (1906) speci­
mens and finds that the specimen coming from Tucumán 
coincides with the description of P. flavescens and transfers 
the other specimen to a new species, P. diversolobatus. On the 
other hand, Carvalho (1944) assigns two female specimens 
from Sao Paulo (Brazil) to P. flavescens. and Sciacchitano 
(1958) assigns one female from Kalimbenge, Uvira (Kivu) in 
the former Belgian Congo (Africa) to/J flavescens. Given that 
the descriptions are insufficient and the distribution offered by 
the literature is curious a reinvestigation of all these speci­
mens is necessary in order to establish their real status.
References
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(Accepted .Time 29,2006)
Unauthenticated
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South American species of Paragordius Camerano, 1897 (Gordiida, Nematomorpha), with redescription of Paragordius minusculus and a description of a new species

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South American species of Paragordius Camerano, 1897 (Gordiida, Nematomorpha), with redescription of Paragordius minusculus and a description of a new species

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