Ecological and reproductive aspects of Neoechinorhynchus pimelodi Brasil-Sato & Pavanelli (Eoacanthocephala, Neoechinorhynchidae) of Pimelodus maculatus Lacépède (Siluroidei, Pimelodidae) of the São Francisco River, Brazil

Ecological and reproductive aspects of Neoechinorhynchus pimelodi Brasil-Sato & Pavanelli, 1998, in Pimelodus maculatus Lacépède, 1803 collected in the São Francisco river during periods of drought (July 1995 and 1996) and floodings (January 1996 and 1997) of this river basin are provided. In tropical regions where the amount of rainfall alters the hydrological regimen of limnological systems water temperature has not had an important role in infections of N. pimelodi in P. maculatus. Prevalence was somewhat higher during drought periods. Intensity of infection varied slightly between collecting periods. Mature male and female acanthocephalans were present in all periods. Females were predominant. Mature females were present in higher numbers during flooding periods with a corresponding decrease in juvenile acanthocephalans. Recruitment and constant losses of N. pimelodi seem to be controlled by transmission mechanisms independently of density. Mechanisms may consist of infected prey availability (potential intermediate hosts) and changes of preferred alimentary items in the diets of juvenile and mature P. maculatus

Helmintos parásitos de Telmatobius jelskii (Peters) (Anura, Leptodactylidae) de Lima, Perú Helminth parasites of Telmatobius jelskii (Peters) (Anura, Leptodactylidae) from Lima, Peru

<abstract language="eng">A quantitative research of parasites of 67 endemic frog Telmatobius jelskii (Peters, 1863) collected from Laguna Tucto (76°46'11"W, 10°39'11"S) where Pativilca River is originated was conducted, and was located in the Province of Oyon, high Andean area from the Department of Lima, Peru during September-October 2000. Of the frogs collected, 23 were females and 44 males. Male showed a length between 5.2 ± 0.5 cm (range = 4.0-6.4 cm) and female between 5.5 ± 1 cm (range = 3.9-7.6 cm) and were not found differences between both sexes. 86 specimens of parasite and three species in total during all the survey were collected. 28 hosts were infected (41.8%). twenty-five hosts (37.3%) showed infection with one parasite species, and three (4.5%) had two parasite species. Three parasite species were found: Gorgoderina parvicava Travassos, 1922 (Digenea: Gorgoderidae) (Prevalence = 40.3%; mean Intensity = 3.1; mean abundance = 1.2), Cylindrotaenia americana Jewell, 1916 (Cestoda: Proteocephalidae) (Prevalence = 3%; mean Intensity = 1; mean abundance = 0.02) and Aplectana hylambatis (Baylis, 1927) (Nematoda: Cosmocercidae) (Prevalence = 3%; mean Intensity = 1; mean abundance = 0.02). G. parvicava had an overdispersed distribution and was the dominant species. An effect of sex and length with prevalence and mean abundance of infection of G. parvicava was not found. The relationship of helminthes parasites with T. jelskii is discussed. G. parvicava and C. americana are new records for T. jelskii