SEASONAL MATURATION OF Catadiscus propinquus (DIGENEA: DIPLODISCIDAE) IN Lysapsus limellus (ANURA: PSEUDIDAE) FROM AN ARGENTINEAN SUBTROPICAL PERMANENT POND.

HAMANN MONIKA INÉS

PHYSIS - A

Estudio Sigma S. R. L.

Lugar: Buenos Aires; Año: 2004 vol. 59 p. 29 - 36

0325-0342

From December 1995 to November 2000, seasonal maturation of Catadiscus propinquus, Freitas & Dobbin, 1956, in its definitive host, the frog Lysapsus limellus Cope, 1862, was studied in a subtropical permanent habitat in the northeast of Argentina. The objectives of this study were: 1) to study the infrapopulation dynamics of parasites analyzing the seasonal maturation cycle throughout the years, and, 2) to examine the relationship between intensity of trematode infection at different developmental stages (recruitment, growth and maturation) and host body length. From 1,400 frogs examined over 60 months (5 years), 30% were found infected with C. propinquus, and the intensity of infection was 1 - 22 trematodes per frog. Specimens of C. propinquus were present in L. limellus throughout the years but did not show a pronounced seasonal cycle of maturation. Invasion of hosts by parasites (stage I) occurred in autumn and spring, coincidentally with the time of greatest frog activity and highest concentration of metacercariae. Growth of parasite specimens (stage II) was observed throughout the seasons. Gravid parasites (stage III) were mainly registered in autumn, winter and spring. The frequency of parasites of different developmental stages increased with increasing frog size.