New host records and a checklist of fishes infected with Austrodiplostomum compactum (Digenea: Diplostomidae) in Brazil

Abstract

This study reports the infection of fishes by Austrodiplostomum compactum metacercariae in the Chavantes reservoir, medium Paranapanema River, municipality of Ipaussu, São Paulo State, Brazil. Twenty-three fish species were analysed, and 13 were infected with A. compactum metacercariae (56.5%) in their eyes. The following six fish species are new hosts for this metacercaria: Crenicichla haroldoi (1/1), Eigenmannia trilineata (11/6), Hoplosternum littorale (11/1), Iheringichthys labrosus (17/2), Leporinus amblyrhynchus (11/1), and Piaractus mesopotamicus (3/1). These new species increase the number of Brazilian fish species infected with this parasite to 36. Based on these findings, we hypothesise that the metacercariae larval stage of the parasite has a low specificity for the second intermediate host (fish). The majority of fish species infected in Brazil belong to the Loricariidae and Cichlidae families. For the fish species with higher mean abundances in Brazil, six are non-native species, and currently, Plagioscion squamosissimus has the highest mean abundance. The majority of fish species infected with A. compactum in Brazil are concentrated in the Paraná basin, although this may be related to the distribution of researchers.Keywords: Freshwater fishes, parasite, Trematoda, metacercariae, infection, Paraná basin. ResumoEste estudo relata a infecção por metacercárias de Austrodiplostomum compactum em peixes do reservatório de Chavantes, médio Paranapanema, Ipaussu, São Paulo, Brasil. Vinte e três espécies de peixes foram analisadas, e 13 estavam infectadas com metacercárias (56,5%) em seus olhos. Seis espécies de peixes foram registradas como novos hospedeiros: Crenicichla haroldoi (1/1), Eigenmannia trilineata (11/6), Hoplosternum littorale (11/1), Iheringichthys labrosus (17/2), Leporinus amblyrhynchus (11/1), and Piaractus mesopotamicus (3/1), aumentando para 36 o número de peixes brasileiros infectados por este parasita. Assim, inferimos que este estágio larval do parasita possui baixa especificidade parasitária em relação ao seu segundo hospedeiro intermediário (peixes). No Brasil, a maioria das espécies de peixes infectadas pertence às famílias Loricariidae e Cichlidae. Quanto às espécies de peixes com as maiores abundâncias médias no Brasil, seis são espécies não-nativas, sendo Plagioscion squamosissimus a espécie com a maior abundância média. Ainda, a maioria das espécies de peixes infectadas por A. compactum no Brasil, estão concentradas na bacia do Paraná, sendo este fato possivelmente relacionado com a distribuição de pesquisadores.Palavras-chave: Peixes de água doce, parasita, Trematoda, metacercária, infecção, bacia do Paraná.

Digenea of Hoplias intermedius and Hoplias malabaricus (Actinopterygii, Erythrinidae) from upper São Francisco River, Brazil

“…In the case of metacercariae of Austrodiplostomum sp., which were already recorded in several fish (a generalist species at that stage of development) in the São Francisco River and other basins (see RAMOS et al, 2013), they were able, as active cercariae, to infect fish (which acted as a second intermediate host) and achieved a good distribution among them across the aquatic environment. In this study, the fact that cercariae of the Austrodiplostomum sp.…”

“…The parasites were processed and preserved according to Amato et al (1991) The prevalence (P) of Austrodiplostomum sp. varied among Siluriform fish (omnivorous adult representatives of Pimelodidae) from São Francisco River, and their rates were occasionally lower than that of adult digenean species in the parasite communities (P. maculatus: P=20.5%, lower than that of Plehniella coelomica Szidat, 1951(= Sanguinicola coelomica (Szidat, 1951 RAMOS et al, 2013). In some studies, those metacercariae showed a higher prevalence rate than the trahiras from the upper São Francisco River (P=60.7% in the Paraná River (SANTOS et al, 2012), and P=57.1% in the mid-Doce River, State of Minas Gerais (BELEI et al, 2013).…”

“…or Diplostomum sp.) in the eyes of fish, their parasitic indices in different water systems were compiled by Ramos et al (2013).…”

Helminth fauna parasitizing Pimelodus pohli (Actinopterygii: Pimelodidae) from the upper São Francisco River, Brazil

“…Studies on parasitism in pimelodids have been also conducted in other localities of Brazil, such as some helminth parasites of species of Pimelodus Lacepède, 1803: P. blochii Valenciennes, 1840in Paraná River (KOHN et al, 1997; P. fur (Lütken, 1874) in Paraná River ; P. maculatus in Amazon Basin in Guaiba River (KOHN;FRÓES, 1986;FORTES et al, 1993;SARMENTO et al, 1995); in Guandu River (SANTOS et al, 2007;ALBUQUERQUE et al, 2008;AZEVEDO et al, 2010); in Itajaí-Açu River (BACHMANN et al, 2007); in Mogi Guaçu River (TRAVASSOS; KOHN, 1965;KOHN et al, 1985;FERNANDES, 1987;AGUIAR et al, 2011); in Paraiba do Sul River (VENANCIO et al, 2010); in Paraná River (TRAVASSOS; KOHN, 1965;MACHADO DOS SANTOS, 1992;MORAVEC et al, 1993MORAVEC et al, , 1997KOHN et al, 1997;PAVANELLI, 2004;KOHN, 2008;KOHN et al, 2011;LOPES et al, 2011); in Paranapanema River (RAMOS et al, 2013); Pimelodus microstoma Steindachner, 1877 in Mogi Guaçu River (AGUIAR et al, 2011) [note of the authors: this fish species was cited by the authors as P. heraldoi Azpelicueta, 2001, that is a junior synonym of P. microstoma Stein., sensu Ribeiro and Lucena (2010) KOHN, 2001;KOHN et al, 2011); Pimelodus sp. in Amazon Basin (VICENTE et al, 1978).…”

Austrodiplostomum compactum metacercariae (Digenea: Diplostomidae) in Schizodon intermedius (Characiformes: Anostomidae) from Jurumirim reservoir, Brazil

“…These results corroborate the observations of Yamada et al (2008), who hypothesized that the larval stage of the parasite species has low specificity for the second intermediate host (fish). According to Ramos et al (2013), the majority of fish species infected with A. compactum metacercariae in Brazil belong to the orders Perciformes (12 species), Siluriformes (13 species) and Characiformes (nine species), and to the families Cichlidae (10 species) and Loricariidae (eight species). Moreover, with the record of the present study, the number of fish species infected with metacercariae of A. compactum in the order Characiformes has now increased to 10.…”