Diplostomum (Austrodiplostomum) compactum (Lutz, 1928) (Platyhelminthes, Digenea) metacercariae in fish from the floodplain of the Upper Paraná River, Brazil

Abstract

Diplostomum (Austrodiplostomum) compactum (Lutz, 1928) metacercariae (Platyhelminthes, Digenea) were found in six fish species, belonging to two orders (Characiformes and Perciformes) and three families (Erythrinidae, Sciaenidae and Cichlidae). A total of 477 individuals were collected, from August 1999 to May 2001, in the upper Paraná River floodplain, Brazil. The metacercariae were infecting the eyes of six host species and the brain of five of them. Plagioscion squamosissimus, Satanoperca pappaterra and Cichla monoculus presented the highest values of prevalence, mean intensity and mean abundance. Diplostomum (A.) compactum was over-dispersed in the population of Hoplias aff. malabaricus, S. pappaterra, P. squamosissimus, Crenicichla britskii and C. monoculus. No significant difference was observed in the metacercariae distribution in the right and left eyes. The abundance of D. (A.) compactum metacercariae was positively correlated with the host's relative condition factor in H. aff. malabaricus and S. pappaterra. No significant difference of the abundance of parasitism between the sex of the hosts was evidenced. In relation to the prevalence, significant difference was observed only in C. britskii. Positive correlations were verified between the prevalence of infection and the standard length of the specimens in C. britskii and the intensity of infection and the standard length of the hosts in P. squamosissimus and C. monoculus. In relation to parasite abundance and the standard length class of the host, significant differences were observed in P. squamosissimus, C. britskii and C. monoculus.

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

“…Studies of the infection of A. compactum in P. squamosissimus showed a prevalence greater than 90% and a mean intensity of infection greater than 20 (KOHN et al, 1995;SANTOS et al, 2002SANTOS et al, , 2012MACHADO et al, 2005;PAES et al, 2010a, b), whereas in the current study, the prevalence was 66.6% and the mean intensity of infection was 13.1±6.1. According to Karvonen et al (2006), the infection dynamics of D. spathaceum in fish is related to the snail population variance.…”

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).…”

Effects of the flood regime on the body condition of fish of different trophic guilds in the Upper Paraná River floodplain, Brazil

“…In this study, our choice to use the mean residuals, obtained from a general equation whose parameters were estimated for each species, resulted from our desire to compare the temporal trends of variation in the body conditions of fish belonging to different trophic guilds; this was done without intending precision. The body condition shown by fish is a result of many environmental factors, such as: physical and chemical variables of the water (Holmes and Yousen, 1994); biotic variables, such as intra-and interspecific interactions (competition, Wyttenbach and Senn, 1993;predation, Dannewitz and Petersson, 2001; diseases and parasitism, Machado et al, 2005;Hoffnagle et al, 2006); factors peculiar to all the species that comprise a guild (e.g., feeding strategies and tactics, reproduction, asymptotic size, Engelhard and Heino, 2006), the availability and quality of food (Luz- Agostinho et al, 2008), and the interactions among these variables (Asaeda et al, 2007). Therefore, a lack of consistency in some results is expected, seeing that some trophic guilds are composed of species with different reproductive strategies, dietary flexibility, or even tolerance to certain environmental conditions, such as fluctuations in oxygen or water levels.…”