The occurrence of Austrodiplostomum compactum (Lutz, 1928) (Digenea: Diplostomidae) metacercariae in the eyes of loricariid fish (Siluriformes: Osteichthyes: Loricariidae) from Brazil

Abstract

The aim of this study was to report the occurrence of Austrodiplostomum compactum metacercariae in the eyes of 98 specimens of loricariid fish (Hypostomus ancistroides, H. hermanni, H. iheringii, H. margaritifer, H. regani, H. strigaticeps, Hypostomus sp. and Megalancistrus parananus) from the Chavantes reservoir (23807 0 36 00 S and 49837 0 35 00 W) located in the rio Paranapanema, upper Paraná river basin, municipality of Ipaussu, São Paulo State, Brazil. Fish were collected from October 2007 to February 2009 using nylon monofilament gill nets and transported to the field laboratory where they were euthanized and the eyes were taken and examined under a stereomicroscope. Hypostomus ancistroides and M. parananus were not infected by this diplostomid. Hypostomus hermanni and H. margaritifer were represented by only one specimen but both had a high intensity of A. compactum metacercarie (27 and 35, respectively). Hypostomus strigaticeps (n ¼ 45) and H. iheringii (n ¼ 28) were the most representative specimens and the prevalence, mean intensity of infection and mean abundance were 24.4%, 10.3 and 2.7, and 64.2%, 13.1 and 8.4, respectively. No correlation was observed between the intensity of infection and the standard length (r ¼ 2 0.223; P ¼ 0.827) and weight (r ¼ 0.03; P ¼ 0.779) of studied fish. Similarly, linear regression among these variables showed a poor correlation and indicated that the infection by A. compactum metacercariae occurs similarly in small and large fish specimens. A seasonal pattern of infection was not observed. Hypostomus hermanni, H. iheringii, H. margaritifer and H. strigaticeps were new hosts recorded for A. compactum metacercariae. A review of morphometric data of A. compactum metacercariae is presented.

The helminth community ofGeophagus proximus(Perciformes: Cichlidae) from a tributary of the Paraná River, Ilha Solteira Reservoir, São Paulo State, Brazil

“…In Brazil, A. compactum metacercariae have been reported in several fish species (Santos et al, 2002;Machado et al, 2005;Yamada et al, 2008;Takemoto et al, 2009;Zica et al, 2009Zica et al, , 2011Paes et al, 2010a, b), and were recently found in G. proximus from the Nova Avanhandava Reservoir, Medium Tietê River, Brazil (Zica et al, 2010). In the present study, the prevalence of A. compactum in G. proximus was lower than that found by Zica et al (2010).…”

Unilatus unilatus Mizelle & Kritsky, 1967 (Monogenea, Ancyrocephalinae) in Hypostomus spp. (Siluriformes, Loricariidae) from the Chavantes reservoir, São Paulo State, Brazil

“…The Chavantes reservoir is located in the middle of the Paranapanema River, between the São Paulo and Paraná States (Zica et al, 2009). The gills were removed from the hosts and placed in vials containing hot water (about 70 -75 ºC).…”

Endohelminths in Cichla piquiti(Perciformes, Cichlidae) from the Paraná River, São Paulo State, Brazil

“…Many fish species are intermediate or definitive hosts of several parasites (ANDERSON, 2000). Austrodiplostomum compactum metacercariae have been found in different hosts in several countries in the Neotropical region (see ZICA et al, 2009ZICA et al, , 2010ZICA et al, , 2011PAES et al, 2010 and references therein), and many Brazilian fish species have previously been found to be infected by these metacercariae (MACHADO et al, 2005 and references there in; KOHN et al, 1995;NOVAES et al, 2006;YAMADA et al, 2008;ZICA et al, 2009ZICA et al, , 2010ZICA et al, , 2011PAES et al, 2010). A high intensity of infection by this parasite in the eyes of fish can cause exophthalmia, retinal detachment, cataracts and blindness (YAMADA et al, 2008), making these fish easy prey and facilitating the transmission of the parasite to the definitive host.…”

“…Moreover, C. piquiti was found to be a new host for parasites, including A. compactum, that were previously introduced into the reservoir through allochthonous host species. This parasite was most likely introduced along with its hosts (MACHADO et al, 2005), and it is able to infect a number of new hosts due to its low host specificity (ZICA et al, 2011).…”