Novas ocorrências de metacercária de Austrodiplostomum compactum (Lutz, 1928) (Platyhelminthes: Digenea) parasito de olhos de peixes da Bacia do Rio Paraná

Digenea of Hoplias intermedius and Odhner, 1902, and Pseudosellacotyla lutzi (Freitas, 1941) Yamaguti, 1953. The prevalence of the metacercariae was higher than that of the adult digeneans of erythrinids from the upper São Francisco River as a result of piscivorous feeding habits of these adult erythrinids. The presence of metacercariae and adult digeneans indicate that they act as intermediate and definitive hosts, respectively, in their biological cycles. Hoplias intermedius is a new host for the four species of Digenea, and the São Francisco River basin is a new location for the known geographical distributions of P. spatula and P. lutzi.

Section: Resultssupporting

confidence: 89%

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

Costa

Monteiro

Brasil-Sato

2015

“…The number of Brazilian fish species infected by A. compactum, including this record, has now increased to 37. 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).…”

supporting

confidence: 91%

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

Ramos

Franceschini

Zago

et al. 2016

This study reports the occurrence of Austrodiplostomum compactum metacercariae in the freshwater fish Schizodon intermedius (ximborê/piava) from a Neotropical reservoir in the Paranapanema River, state of São Paulo, Brazil. From a total of 75 fish collected, we found 38 infected with A. compactum metacercariae (prevalence = 50.67%) in the eyes. The mean intensity of infection and mean abundance were 9.05 ± 4.26 (1-155) and 4.59 ± 2.20 (0-155), respectively. Poulin's Discrepancy Index was 0.87 and four specimens presented more than 10 metacercariae in their eyes. No correlation was observed between parasite abundance and standard length, total weight and condition factor (p>0.05). These metacercariae are reported for the first time in S. intermedius.Keywords: Freshwater fish, eyefluke, ximborê, Paranapanema River, Paraná River basin. ResumoEste estudo reporta a ocorrência de metacercárias de Austrodiplostomum compactum na espécie de peixe de água doce Schizodon intermedius (ximborê/piava), oriunda de um reservatório Neotropical no rio Paranapanema, Estado de São Paulo, Brasil. Um total de 75 peixes foram coletados, sendo que 38 estavam infectados com metacercárias de A. compactum (prevalência = 50,67%) nos olhos. A intensidade média de infecção e abundância média foram 9,05 ± 4,26 (1-155) e 4,59 ± 2,20 (0-155), respectivamente. O Índice de Discrepância de Poulin foi de 0,87, e quatro exemplares apresentaram mais do que 10 metacercárias em seus olhos. Não foram observadas correlação entre abundância média e comprimento padrão, peso total e fator de condição (p>0,05). Esse é o primeiro registro dessa espécie de metacercária para S. intermedius.Palavras-chave: Peixe de água doce, trematódeo parasita de olho, ximborê, rio Paranapanema, bacia do rio Paraná. (KARVONEN et al., 2006;VIOLANTE-GONZÁLEZ et al., 2009). Adults of diplostomids release their eggs into water via the feces of infected piscivorous birds, and hatching of free-swimming larva (miracidia) can occur up to 22 days later, depending on the water temperature (GROBBELAAR et al., 2014). In Brazil, miracidium actively infect aquatic snails of the genus Biomphalaria Preston, 1910 (PINTO & MELO, 2013, and polyembriony occurs in the digestive gland and liver of snails (CROWDEN & BROOM, 1980;HOFFMAN & HUNDLEY, 1957). Infected snails release cercariae, which actively infect fish (second intermediate host), preferentially through their gills and mouth (HAAS et al., 2007), although penetration may also occur through their fins and body surface (GROBBELAAR et al., 2014).In fish, the parasites develop to the metacercariae, which generally parasitize the eyes ) and brain (GROBBELAAR et al., 2014). The adult/reproductive form of this parasite species is found in the digestive system of piscivorous birds, when these birds feed on infected fish. Neotropical cormorants, Phalacrocorax brasilianus (Gmelin, 1789), which are a widespread generalist species, are considered to be the definitive host of this diplostomid in Brazil (MONTEIRO et al., 2011).According to Grob...

“…Thus, the number of Brazilian fish species infected by A. compactum increased to 36, and the number of families parasitised for 13. Based on these observations, we hypothesise that this larval stage of the parasite has a low specificity for the second intermediate host (fish), similar to that reported by Yamada et al (2008). In addition, the six new hosts identified in the present study demonstrates that parasitological studies with fish communities should significantly expand the list of fish identified as second intermediate hosts for A. compactum.…”

Section: Discussionsupporting

confidence: 88%

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

Ramos

Franceschini

Zago

et al. 2013

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.