Results: 133

Ontogenetic change in the diet of Semaprochilodus insignis (Characiformes: Prochilodontidae) during migration between two limnologically distinct environments in the Amazon Basin

Neotrop. ichthyol; 19 (4), 2021
Semaprochilodus insignis is an Amazonian migratory fish species, moving in large shoals between white- and black-water rivers. It has long been classified as a detritivorous fish. However, it is possible that the trophic plasticity of S. insignis could be higher than previously assumed. The objective of ...

Feeding aspects of Knodus heteresthes (Eigenmann, 1908) and Moenkhausia lepidura (Kner, 1858) (Characiformes, Characidae) in the Teles Pires and Juruena Rivers, southern Amazon

Braz. j. biol; 81 (2), 2021
The composition of the diet of two species of characids (Knodus heteresthes and Moenkhausia lepidura) was evaluated in the Teles Pires and Juruena Rivers, sampled in September and October 2016. We analyzed 226 stomachs of K. heteresthes and 425 of M. lepidura. The analysis of the stomach contents was bas...

Chromosome analysis in Saccodon wagneri (Characiformes) and insights into the karyotype evolution of Parodontidae

Neotrop. ichthyol; 19 (1), 2021
Parodontidae is a relatively small group of Neotropical characiform fishes consisting of three genera (Apareiodon, Parodon, and Saccodon) with 32 valid species. A vast cytogenetic literature is available on Apareiodon and Parodon, but to date, there is no cytogenetic data about Saccodon, a genus that con...

Adjustments in population and reproductive dynamics of native and non-native congeneric species during 26 years after invasion

Neotrop. ichthyol; 19 (1), 2021
We aimed to improve the understanding of the establishment of Serrasalmus marginatus (non-native), which was followed by a decrease in the abundance of Serrasalmus maculatus (native) in the upper Paraná River floodplain. We estimated age, mortality rate, length and age at first maturity and variations i...

A new, narrowly distributed, and critically endangered species of Characidium (Characiformes: Crenuchidae) from the Distrito Federal, Central Brazil

Neotrop. ichthyol; 19 (1), 2021
A new species of Characidium is described from the Cerrado biome, in Brasília, Distrito Federal, Central Brazil. The new species can be readily diagnosed by the presence of two or three longitudinal rows of dots along the body sides, absence of bars, by the short pectoral fin, which does not reach the v...

Centesimal composition and meat yield of Hoplias malabaricus: association with intestinal parasites

Abstract Hoplias malabaricus is a non-migratory fish commonly found in the Mogi Guaçu River basin, mainly feeding on fish, small crustaceans and insects. It forms part of the diet for humans, birds and some mammals. This fish has great nutritional value, with both good quality and good quantities of ess...

Diversity of metazoan parasites in fish Triportheus angulatus and Triportheus auritus living in sympatry in the Brazilian Amazon

Abstract The aim of this study was to compare the diversity and community structure of metazoan parasites in sympatric populations of Triportheus angulatus and Triportheus auritus in the Jari River basin, in the eastern Brazilian Amazon. All the specimens of T. angulatus and T. auritus examined were infe...

Hepatic coccidiosis in Serrasalmus rhombeus Linnaeus, 1766 from the Amazon basin: morphological and histopathological aspects

Abstract Calyptospora species are coccids that commonly cause liver infections in fish all around the world. This paper describes the morphology and histopathological characteristics of liver infection caused by Calyptospora sp. in black piranha Serrasalmus rhombeus, from the Capim River, in the municipa...

Age-associated hemogram and ultrastructural leukocyte morphology in Pygocentrus nattereri (Characiformes: Serrasalmidae) from the Brazilian Pantanal

Neotrop. ichthyol; 19 (1), 2021
Pygocentrus nattereri is a carnivorous fish widely distributed in the Brazilian wetland and occupies different river strata. Based on the sexual maturity, the standard length (SL) has been used to categorize age and physiological attributes. However, hematological parameters and their relationship with a...

Community and infracommunities of metazoan parasites in Hemiodus unimaculatus (Hemiodontidae) from Jari River basin, a tributary of Amazon River (Brazil)

Abstract Parasites are an important part of biodiversity, and knowledge of species and their relationship with their hosts helps in monitoring an ecosystem over time. The aim of this study was to investigate the fauna of metazoan parasites in Hemiodus unimaculatus from the Jari River, in the eastern Amaz...