Este trabalho apresenta o estudo cienciométrico dos parasitos de peixes de cultivo do Brasil, incluindo significativa revisão da literatura. A metodologia adotada se baseou na pesquisa dos artigos feita no mês de maio de 2012 em três bancos de dados: ISI (Institute for Scientific Information), SciELO (Scientific Electronic Library Online) e Google Acadêmico. O número de artigos sobre parasitos de peixes cultivados está aumentando (autalmente mais de 110), havendo um crescimento a partir de 1995. Entretanto o número ainda é baixo se comparado ao número de artigos de parasitos de peixes de ambientes naturais. No Brasil, os peixes de cultivo mais estudados são pacu, tilápia e tambaqui. Os monogenéticos foram os grupos mais prevalente, seguido de protozoários e crustáceos. As regiões mais pesquisadass foram o sudeste e sul, perfazendo 84% da produção bibliográfica total. O principal assunto abordado nos artigos foi patologia, seguido por tratamento e registro. Conclui-se que os tratamentos das parasitoses de peixes de piscicultura no Brasil ainda são incipientes, ressaltando a importância e utilidade das boas práticas de manejo para evitar o aparecimento de problemas sanitários.

This paper presents a science metric study of parasites of fish farming in Brazil, including a significant review of the literature. The methodology used was based on researching articles in three different databases, carried out on May 2012: ISI (Institute for Scientific Information), SciELO (Scientific Electronic Library Online), and Google Academic. The number of articles on fish parasites is mounting (currently over 110), having much increased since 1995. However, the quantity is still low compared with the amount of papers on parasites of fish from natural environments. In Brazil, the farmed fish that have been studied the most are pacu, tilapia and tambaqui. Monogeneans represent the most prevalent group, followed by protozoa and crustaceans. The regions most researched were the southeast and south, making up 84% of the total literature. The main issue addressed in articles was pathology, followed by treatment and record. In conclusion, the treatment of parasitic diseases of farmed fish in Brazil is still incipient, highlighting the importance and usefulness of management practices to prevent the occurrence of health problems.

Specimens of monogeneans parasites found in the nasal cavities of Pimelodus maculatus from the São Francisco and Paraná rivers were identified as Pavanelliella pavanellii. Prevalence, mean intensity and mean abundance this species are presented. An ecological analysis of the results related to the drought periods and full of the river Paraná evidences that P. pavanellii is more abundant in the rainy station, whose temperature is higher. Pavanelliella pavanellii from P. maculatus is for the first time registered to São Francisco river, southeast Brazil.

Espécimes de monogenóideos parasitos das cavidades nasais de Pimelodus maculatus dos rios São Francisco e Paraná foram encontrados e identificados como Pavanelliella pavanellii. Prevalência, intensidade média e abundância média de P. pavanellii em P. maculatus são apresentadas para os dois sistemas hídricos. Resultados da análise ecológica relacionados à períodos de seca e cheia do rio Paraná evidenciaram elevação da abundância média de P. pavanelli no período de cheia, no qual a temperatura é mais alta. Pavanelliella pavanellii é o primeiro registro de monogenóideos das cavidades nasais de P. maculatus e é pela primei-ra vez encontrada no rio São Francisco, Brasil.

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.

Rhinoxenus bulbovaginatus n. sp. is described from the nose of Salminus maxillosus (Characidae) collected in the basin of the rio Paraná, near the city of Porto Rico, state of Paraná, Brazil. The new species can be differentiated from the other three species in the genus by the morphology of the copulatory complex, vagina, and ventral anchor. The sister group relationship of the known species of Rhinoxenus was determined using techniques of Phylogenetic Systematics (Cladism). The resulting cladogram (C.I.=100%) indicates that the new species is most closely related to R. piranhus Kritsky, Boeger and Thatcher, 1988. The other two species of the genus, R. arietinus Kritsky, Boeger and Thatcher, 1988 and R. nyttus Kritsky, Boeger and Thatcher, 1988, both parasites of Anostomidae fishes, have a paraphyletic position in the cladogram, suggesting that the origin of at least one of them can not be associated to cospeciation.

Two species of the genus Proteocephalus (Cestoda: Proteocephalidae) were collected in fishes from the Paraná River. Proteocephalus vazzolerae n. sp. from Piaractus mesopotamicus and Proteocephalus chubbi, n. sp. from Gymnotus carapo are new species, and are described and illustrated. Proteocephalus vazzolerae n. sp. is characterized mainly by the number of testes and the development of vitellaria. Proteocephalus chubbi n. sp. can be differentiated from its congeners by a combination of characters which include, number of testes, number of proglottids, strobila length, scolex shape and disposition of vitellaria. This is the first record of proteocephalidean in P. mesopotamicus and G. carapo.

One hundred and ten specimens of Pseudoplatystoma corruscans (Agassiz, 1829) (Pimelodidae), "pintado", and 582 specimens of Schizodon borelli (Boulenger, 1900) (Anostomidae), "piava", collected in the floodplain of the high Paraná River were analyzed. P. corruscans presented 74.54% of parasitism while S. borelli presented 19.42%. Results of the present research show that in the case of P. corruscans, two species of proteocephalideans presented a significant relationship with the type of environment with regard to prevalence. Spasskyelina spinulifera (Woodland, 1935) was the only species that presented a relationship between the intensity of infection and the environment. In S. borelli only Cucullanus pinnai Travassos. Artigas & Pereira, 1928 presented a relationship with the environment. In this case the mean intensity was greater in lentic environments. The high values of the similarity index in the three environments studied indicate a considerable homogeneity of the endohelminths' species with regard to P. corruscans and S. borelli. This is probably due to what occurs with environments during the high water period when they are interlinked. The hydrological level was a less influential variable in endoparasitic infrapopulations of the hosts studied. In P. corruscans only three species, S. spinulifera, Nomimoscolex sudobim Woodland, 1934 and Megatnylacus travassosi Pavanelli & Rego, 1992 presented higher mean intensities in the high water period. This fact was also observed in the case of C. pinnai in S. borelli.