Relative condition factor and parasitism in anostomid fishes from the floodplain of the Upper Paraná River, Brazil

Abstract

Individuals of four species of Leporinus were captured in the floodplain of the Upper Paraná River and their metazoan parasites were collected. Fifty-eight taxa of ectoparasites and endoparasites were recorded: 31 in Leporinus lacustris, 32 in Leporinus friderici, 28 in Leporinus obtusidens and 25 in Leporinus elongatus. The aim of this paper was to study the relationship between the host's condition and the parameters of infrapopulations and infracommunities. The health of the host was represented by the relative condition factor (Kn). Richness and number of individuals in the infracommunities of ectoparasites covariated with the Kn of the hosts in one species of fish. Some infrapopulations of ectoparasites covariated negatively and/or the mean Kn of parasitized individuals was lower than those without parasites. The abundance in some infrapopulations of endoparasites covariated positively with the Kn and/or the mean Kn of parasitized fish was better. These results may be related to different transmission strategies used by ecto and endoparasites.

A new species of Tereancistrum (Monogenea, Dactylogyridae) from the gills of three Leporinus species (Characiformes, Anostomidae) and a revised description of Tereancistrum parvus

“…The prevalences of this monogenean in L. friderici (12.5%) and L. elongatus (10%) were similar to those reported by Guidelli et al (2011) in the floodplain of the Upper Paraná River, Brazil (3.8% and 17.9%, respectively).…”

“…Ventral bar. ALINE C. ZAGO et al reported in L. fasciatus (Kritsky et al 1980), Leporinus lacustris (Amaral Campos, 1945), Leporinus obtusidens Valenciennes, 1847(Guidelli et al 2011), S. borellii (Karling et al 2014, and L. friderici, L. elongatus, and S. nasutus (present study); T. paranaensis in S. borellii (Karling et al 2014), L. obtusidens (Wendt et al 2015) and Schizodon intermedius Garavello andBritski, 1990 (Abdallah et al 2016), and T. flabellum n. sp., reported in L. friderici, L. elongatus and L. amblyrhynchus.…”

Morphological and morphometric features of nematode-cysts in Gymnotus inaequilabiatus liver in the Brazilian Pantanal

“…Consequently, different histopathological aspects are observed and reported in the literature based on the degree of infection, tissue affected, host immune system, and magnitude of inflammatory response (POOLE & DICK, 1984;ALVAREZ-PELLITERO, 2008;ROBERTS, 2012). Microscopic examinations have revealed insignificant tissue changes despite evidence of considerable infection in most histological sections, indicating the complex interactions between the pathogen and host as well as the difficulty in establishing pathological patterns related to lethality in fish under natural conditions according to Poulin (1992) and Guidelli et al (2011). In addition, samples of larvae in the L3 stage remained in the tissue with irrelevant deleterious effect, reducing the pathogenicity and probably the mortality in this fish species.…”

Diversity of parasites in wild Astronotus ocellatus (Perciformes, Cichlidae), an ornamental and food fish in Brazil

“…Fish are hosts to diverse ecto -and endoparasite species that can significantly affect their behavior, metabolism, fecundity, growth, survival and body condition. Studies on body condition or welfare generally use length and body mass relationships of hosts, assuming that heavier fish of a given length are in better condition (Guidelli et al 2011, Losee et al 2014, Lagrue and Poulin 2015. However, fish welfare is a complex concept and it can be approached from nutritional, biological and health perspectives.…”