Aline Rodrigues Paraguassú

Community ecology of the metazoan parasites of pink cusk-eel, Genypterus brasiliensis (Osteichthyes: Ophidiidae), from the coastal zone of the State of Rio de Janeiro, Brazil

Fifty-five specimens of pink cusk-eel, Genypterus brasiliensis Regan, 1903 (Osteichthyes: Ophidiidae) collected from the coastal zone of the State of Rio de Janeiro, Brazil (approx. 21-23 degrees S, 41-45 degrees W), from September 2000 to January 2001, were necropsied to study their parasites. All fish were parasitized by one or more metazoan. Fourteen species of parasites were collected. G. brasiliensis is a new host record for nine parasite species. The larval stages of cestodes and the nematodes were the majority of the parasite specimens collected, with 38.4% and 36.5%, respectively. Cucullanus genypteri was the dominant species with highest prevalence and/or abundance. The parasites of G. brasiliensis showed the typical overdispersed pattern of distribution. Six parasite species showed correlation between the hosts total body length and prevalence and abundance. Host sex did not influence prevalence and parasite abundance of any parasite species. The mean diversity in the infracommunities of G. brasiliensis was H= 0.364 +/- 0.103, with correlation with the hosts total length and without differences in relation to sex of the host. One pair of adult endoparasites (C. genypteri and A. brasiliensis) showed positive covariations between their abundances. Negative association or covariation was not found. Differences between the qualitative and quantitative aspects of the parasite community of G. brasiliensis from Rio de Janeiro and Argentina suggest the existence of two population stocks of pink cusk-eel in the South America Atlantic Ocean.

A new species of Anoplodiscus (Monogenea: Anoplodiscidae) parasitic on Pagrus pagrus (Osteichthyes: Sparidae) from the coastal zone of the State of Rio de Janeiro, Brazil

A new species of Anoplodiscus (Monogenea, Anoplodiscidae), parasitic on gills of the red porgy, Pagrus pagrus, from the coastal zone of the State of Rio de Janeiro, Brazil, is described and illustrated. The new species can be differentiated from the other species of this genus by the shape of the accessory piece of the copulatory complex, and the length of the vagina. This is the first record of a species of Anoplodiscus in the Neotropical region.

Metacercárias de Clinostomum marginatum (Digenea: Clinostomidae) em acará-bandeira Pterophyllum scalare (Osteichthyes: Cichlidae) no estado do Rio de Janeiro, Brasil

The present study recorded by the first time metacercariae of the digenetic Clinostomum marginatum (Clinostomidae) infecting specimens of the ornamental fish Pterophyllum scalare, from the State of Rio de Janeiro, Brazil. Parasites were found encysted on the fins of the fish, forming small, white-yellowish, nodules

Aspectos ecológicos de las infrapoblaciones de Cucullanus genypteri (Nematoda: Cucullanidae) parásito del congrio rosado, Genypterus brasiliensis (Osteichthyes: Ophidiidae) del litoral del estado de Rio de Janeiro, Brasil

Entre septiembre de 2000 y enero de 2001 fueron necropsiados 55 especimenes de congrio rosado, G. brasiliensis procedentes de la costa del estado del Rio de Janeiro (21-23° S, 41-45° W), Brasil. Todos los congrios examinados estaban parasitados por C. genypteri, colectandose un total de 1.312 especimenes; con abundancia media de 23,8 ± 26,7. Cucullanus genypteri presento un tipico patron de distribucion sobredispersa o contagiosa. La abundancia de C. genypteri presento correlacion positiva con el tamano corporal del hospedador. El sexo de los peces no influencio en la abundancia del parasito.