Aplectana artigasi n.sp. (Nematoda: Cosmocercidae) from the Frog Eupsophus calcaratus (Anura: Leptodactylidae) in Southern Chile

Vol. 92(6): 767- 770

Sonia Puga⁺, Patricio Torres

Instituto de Parasitología, Universidad Austral de Chile, Isla Teja, Casilla 567, Valdivia, Chile

A new species of nematode found in the intestine of Eupsophus calcaratus (Anura: Leptodactylidae) from Yaldad, Chile (45°5'S;73°43'W) is described. This new nematode is compared with other South American species of the genus. Aplectana artigasi differs from the only known Chilean species, Aplectana chilensis, as the former has a greater number of postanal papillae and a double papilla in the ventral region of the tail.

Key words: Aplectana artigasi n.sp. - Nematoda - intestine - Leptodactylidae - frogs - Chile

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Nematode species of the genus Aplectana Railliet & Henry, 1916 are intestinal parasites of reptiles and amphibians (Travassos 1931, Yorke & Maplestone 1969, Baker 1980, 1987). In Chile, the genus is represented by Aplectana chilensis Lent & Freitas, 1948 from the toads Rhinoderma darwinii Dumeril & Bibrón, 1841 (Puga 1994) and Pleurodema thaul (Benavides et al. 1996). Aplectana spp. are found in North America, Europe, Asia, South America and Africa (Travassos 1931, Baker 1980, Adamson & Baccam 1988, Dyer 1990). In South America about 19 species of Aplectana have been described from toads (Travassos 1931, Lent & Freitas 1948, Baker 1980, 1987, Baker & Vaucher 1986, Adamson & Baccam 1988).

In the present paper a new species of Aplectana is described from Eupsophus calcaratus (Günther, 1881) (Leptodactylidae), a toad of the temperate forests of Chile.

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MATERIALS AND METHODS

DESCRIPTION

REMARKS

REFERENCES

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MATERIALS AND METHODS

Twenty six female and five male nematodes of the genus Aplectana were removed from the intestine of three adults of E. calcaratus from Yaldad (45°5'S; 73°43'W), on the Isla Grande of Chiloé, Chile. The nematodes were fixed in 70% ethanol and cleared in lactophenol for morphological study. Measurements are in µm, unless otherwise indicated. Ranges are followed by averages in parenthesis.

The following type material from the Helminthological collection of the Instituto Oswaldo Cruz, Brazil was studied: A. crucifer Travassos, 1925 (coll. No. 5173), A. bonariensis (Gutiérrez, 1945) (coll. No. 16600 a,b,c), A. crossodactyli (Baker, 1980) (coll. No. 30466 c,d) and A. delirae (De Fabio, 1971) (coll. No. 30591 m, j). Specimens of A. chilensis (coll. No. 231555) from Museo of Zoología de la Universidad de Concepción, Chile, were also studied.

 

DESCRIPTION

Aplectana artigasi n.sp.

(Figs 1-5)

Small slender worms. Cuticle bearing transverse striations from posterior to lips to tail. Triangular oral opening surrounded by one dorsal and two subventral lips. Each lip with a cuticular flap on anterior edge. Cephalic sense organs consisting of inner circle of 6 min papillae and a circle of four outer submedian papillae, one on each subventral lip and two on dorsal lip. Two large amphids present. Lateral alae narrow extending from 70-74 posterior to cephalic extremity to anal region in female and in males, beyond the anus. Anterior part of oesophageal corpus small compared to posterior one; isthmus small and bulb provided with valvular apparatus. Excretory pore a broad transverse slit with fringed border situated between anterior and medial region of the bulb.

Female (11 specimens). Body 3.8-6 (5.2) mm long. Maximum width 350-490 (414.9). Buccal cavity 7-28 (12.5) long, anterior part of oesophageal corpus 28-56 (40.7) long, posterior region of oesophageal corpus 364-546 (427) long, isthmus 14-28 (25.2) long. Bulb 112-168 (133) long with 126-196 (155.6) wide. Nerve ring 174,5-227 (191.8) and excretory pore 434-546 (492.8) from anterior end, respectively. Vulva to anterior 2.3-3.3 (2.8) mm and posterior extremity 2.1-2.9 (2.5) mm, respectively. Tail 690-952 (823.3) long, slender, sharply pointed. Eggs in uteri, thin shelled with embryos in different stages of development up to larvae, 69-124.2 (100.8) long 41.4-82.8 (67.9) wide.

Male (3 specimens). Length 3-4 (3.4) mm. Maximum width 294-350 (322). Buccal cavity 14 long, anterior part of oesophageal corpus 28, posterior region of oesophageal corpus 294-378 (340.7) long. Isthmus 14 long. Bulb 98-182 (126) long, 112 maximum wide. Nerve ring 150.7 and excretory pore 378-434 (406) from anterior end, respectively. Spicules 322-364 (345.3) long, curved ventrally in distal part. Without gubernaculum. Tail 528-780 (619.3) long, slender, sharply pointed. Preanal region with up to 14 pairs of papillae. One unpaired papilla on anterior lip of anus and one pair adanal. Ten to 14 pairs of papillae on the tail, from this, 6 last pairs were constant in number and position. One unpaired double papilla on ventral region of tail.

Host type: Eupsophus calcaratus (Günther, 1881) (Anura: Leptodactylidae)

Site of infection: intestine

Locality: Yaldad (43°5'S;73°43'W), Isla Grande de Chiloé, Chile

Type material: deposited in the Instituto de Parasitología Collection, Universidad Austral de Chile (IPUAT) No. 0249 (Holotype male), No. 0250 (Allotype female) and No. 0251 (Paratypes).

Etymology: this species is dedicated to our professor Dr Jorge Artigas Jara in recognition of his contributions to the development of Parasitology and Public Health in Chile.

 

REMARKS

A study of one female and one male of A. chilensis (coll. No. 231555), from P. thaul (Benavides et al. 1996) showed the characteristics of the original description of Lent and Freitas (1948), but the male specimen showed one unpaired papilla on the anterior lip of the anus, a characteristic that was not mentioned in the original paper.

Examination of the poorly processed type material of A. crossodactyli (coll. No. 30466 c, d), A. delirae (coll. No. 30591 m, 30591 j) and A. crucifer (coll. No. 5173) did not reveal details of the spicules and gubernaculum. Specimens of A. bonariensis (coll. No. 16600 a, b, c), considered by Baker (1987) as a synonym of A. hylambatis, showed a gubernaculum and spicules.

The type material of A. chilensis and A. meridionalis was requested for study from the Museo de Montevideo, Uruguay, but unfortunately it was not received.

Compared with descriptions of the above mentioned species by Miranda (1924), Travassos (1931), Lent and Freitas (1948), da Silva (1954), Pallarés and Maciel (1974) Baker (1980), Baker and Vaucher (1986) and Dyer (1990), the new species can be distinguished from A. membranosa, A. micropenis, A. vellardi, A. hylambatis, A. lopesi, A. elenae, A. paraelenae, A. pudenda, A. travassosi, and A. macintoshii because it does not have a gubernaculum. A. artigasi n.sp. has a smaller number of caudal papillae than A. crucifer and A. meridionalis with 11 and 14 pairs of papillae respectively. The new species differs from A. chilensis because it has a larger number of postanal papillae, and it has an unpaired double papilla on the ventral region of the tail. The described species also differs from A. crucifer because it presents a prominent papilla on the anterior border of the anus and from A. meridionalis because its spicules are two or three times longer.

 

REFERENCES

• Adamson M, Baccam D 1988. Systematic revision of the Atractidae sensu Chabaud (1978) (Nematoda; Cosmocercoidea): Maracaya belemensis n. sp. and Aplectana albae n. sp. from Amphisbaena alba in Brazil. Can J Zool 66: 1857-1864.
• Baker M 1980. Revision of Old World species of the genus Aplectana Railliet and Henry, 1916 (Nematoda, Cosmocercidae). Bull Mus Natn Hist Nat Paris Ser 4 Sect A 2: 955-998.
• Baker M 1987. Synopsis of the Nematoda Parasitic in Amphibians and Reptiles. Memorial University of Newfoundland, Occasional Papers in Biology, 325 pp.         [ Links ]
• Baker M, Vaucher C 1986. Parasitic helminths from Paraguay. XII: Aplectana Railliet & Henry, 1916 (Nematoda: Cosmocercoidea) from frogs. Rev Suisse Zool 93: 607-616.         [ Links ]
• Benavides M, Ortíz JC, Jerez V 1996. Primer registro parasitológico en Pleurodema thaul, Lesson, 1826 (Anura; Leptodactylidea). Parasitol al Día 20: 59-62.
• da Silva J 1954. Nova espécie do gênero Aplectana Railliet & Henry, 1916 (Nematoda, Cosmocercidae). Mem Inst Oswaldo Cruz 52: 415-418.         [ Links ]
• Dyer WG 1990. Augmented description of Aplectana travassosi (Nematoda: Cosmocercidae) from leptodactylid frogs of Ecuador. J Parasitol 76: 639-640.
• Lent H, Freitas JFT 1948. Uma coleção de nematódeos, parasitos de vertebrados do Museu de Historia Natural de Montevideo. Mem Inst Oswaldo Cruz 46: 1-71.         [ Links ]
• Miranda C 1924. Alguns nematódeos do género Aplectana Railliet & Henry, 1916. Mem Inst Oswaldo Cruz 17: 45-49.         [ Links ]
• Pallarés R, Maciel S 1974. Helminthes en batracios del Paraguay (1^era parte), con descripción de una nueva especie, Aplectana pudenda (Oxyuridae: Cosmocercinae). Rev Paraguaya Microbiol 9: 55-60.
• Puga S 1994. Fauna helmintológica en anuros chilenos. Bol Chil Parasitol 49: 81-84.         [ Links ]
• Travassos L 1931. Pesquizas helminthologicas realizadas em Hamburgo. IX Ensaio monographico da familia Cosmocercidae Trav., 1925 (Nematoda). Mem Inst Oswaldo Cruz 25: 237-298.         [ Links ]
• Yorke W, Maplestone PA 1969. The nematode parasites of vertebrates. Hafner Publishing Company, New York and London, 536 pp.         [ Links ]

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This work was supported by Grant no. S-94-34 (Dirección de Investigación y Desarrollo, Universidad Austral de Chile).

⁺Corresponding author. Fax: +56-63-214475

Received 9 January 1997

Accepted 30 July 1997

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