Mem Inst Oswaldo Cruz, Rio de Janeiro, Vol. 95(1): 81-82, Jan./Feb. 2000

Short communication

Francisco Brusa⁺, María Cristina Damborenea

Departamento Científico Zoología Invertebrados, Facultad de Ciencias Naturales y Museo, UNLP, Paseo del Bosque s/nº, 1900 La Plata, Argentina

Received 15 July 1999
Accepted 11 November 1999

Temnocephala brevicornis Monticelli 1889, ectosymbiont of Hydromedusa tectifera Cope 1869, is reported for the first time for Argentina. Numerous temnocephalans from Arroyo Villoldo in the locality of Magdalena, Buenos Aires, Argentina were stained in toto to be studied. This commensal species in turtles was originally cited in association with Hydromedusa maximiliani (Mikan) and Hydraspis radiolata Mikan in Brazil. Afterwards, it was found on other fresh water turtle species in Brazil and Uruguay.

Key words: Temnocephala - Hydromedusa tectifera - South America - Argentina

The Temnocephalidae includes symbiotic turbellarians from Australia, New Zealand, New Guinea, Madagascar, Central and South America (Williams 1981). The first Temnocephalan described was Temnocephala chilensis (Moquin-Tandon, 1846) found in association with an anomuran crab, Aegla laevis (Laitreille, 1818), from near Santiago, Chile. Since then, 19 species of Temnocephala have been reported in South and Central America associated with a large variety of hosts (crustaceans, molluscs, insects and turtles). Nine of these have been found in Argentina (Damborenea 1992).

The present short communication represents the first record of T. brevicornis for Argentina. This species was found on the surface of Hydromedusa tectifera Cope 1869. This turtle has a wide distribution in South America; from the states of Rio Grande do Sul and Santa Catarina in Brazil, Paraguay and Uruguay. In Argentina H. tectifera can be found from the northeast (Formosa, Chaco, Santa Fé, Córdoba, Misiones, Corrientes and Entre Ríos) to the latitude of 37º South in the basin of the Salado river, Buenos Aires (de la Fuente 1992)

T. brevicornis Monticelli, 1889 is the only species to have been found on a turtle. It was first described associated with H. maximiliani (Mikan) and Hydraspis radiolata Mikan in Brazil. Subsequently, other hosts and localities have been reported, as follows:

H. maximiliani (Mikan) from Teresópolis, Rezende, Angra dos Reis, Rio de Janeiro, and Viçosa, Minas Gerais, Brazil (Pereira & Cuocolo 1940, 1941);

H. tectifera Cope from São Paulo, Brazil (Pereira & Cuocolo 1941); Valle Edén, Tacuarembó, Uruguay (Dioni 1967);

Mesoclemmys (Schw.) (=Hydraspis Schw.) Brazil (Monticelli 1899);

Acanthochelys spixii (Duméril et Bibron, 1835) Viamão, Rio Grande do Sul, Brazil (Ferreira Yuki et al. 1993);

Trachemys dorbigni (Duméril et Bibron, 1835) Viamão, Rio Grande do Sul, Brazil (Ferreira Yuki et al. 1993).

Thus, the presence of T. brevicornis is known from Brazil and Uruguay. Moreover it has also been refereed in association to Pseudotelphusa sp. (Crustacea) in Venezuela and in El Salvador (Lamothe Argumedo 1974). However, this reference is in some doubt since it is the only one for a crustacean host.

Numerous temnocephalans were found on the surface of three specimens of H. tectifera, from Arroyo Villoldo and Ruta 11, in the locality of Magdalena, Buenos Aires, Argentina (35º 15.936'S-57º15.536'W). Owing to their large size and active movements, these commensals are very evident when they alive. Approximately 50 young and adult specimens were fixed in 10% formaldehyde, stained with hydrochloric carmine and mounted in Canadian balsam. The specimens have been deposited in the Helminthological Collection of the La Plata Museum (MLP 4585) Argentina.

T. brevicornis has been well described by Pereira and Cuocolo (1940). These authors described the penis, now considered most relevant in specific identification (Cannon 1993), as a conical elongated structure 360 µm long, 100 µm of basal diameter and 40 µm of distal diameter. The distal end is slightly dilated. The inner distal surface has several rows of small thorns. These features and measurements have also been reported by Ferreira Yuki et al. (1993).

The specimens studied here presented similar structural characteristics to those studied by Pereira and Cuocolo (1940), but were smaller ( Table).

In particular the penis is shorter and narrower but it demonstrates the same morphology.

Supported by CIC and Conicet.

REFERENCES

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