Results: 132

Acute and subchronic effects of petroleum on the freshwater fish Hoplias aff. malabaricus

Braz. j. biol; 84 (), 2024
Abstract Petroleum water soluble fraction (WSF) impairs organisms, but damages may vary among cell and tissue levels. The aim of the present study was to evaluate the acute (24 h, 48 h, 72 h) and subchronic effects (36 days) of WSF (0%, 25% and 100%) in juveniles of the Neotropical top predator fish Hopl...

Trophic ecology of Acestrorhynchus falcirostris Cuvier, 1819 in island lakes on the lower stretch of the Solimões River, Amazon Basin

Braz. j. biol; 84 (), 2024
Abstract The aim objective of this study was to determine the trophic ecology of juvenile and adult Acestrorhynchus falcirostris during the rising and flood (high-water) period in six island lakes adjacent to the Solimões River. As such, we investigated: i) the trophic position, through the fractional t...

Anatomical and histological traits of Brycon amazonicus liver cultivated in a semi-intensive system

Braz. j. biol; 83 (), 2023
Abstract The work aimed to evaluate the weight-length relationship and the condition factor, characterizing the biometry, anatomy, histology and volumetric density of the liver of Brycon amazonicus, in different stages of body growth. The experiment used twenty specimens in four stages of body growth (PI...

Length-weight relationships of fish from sandy beaches

Braz. j. biol; 83 (), 2023
Abstract This study estimated the length-weight relationships of 16 fish species occurring close to the shores of sandy beaches along the lower Negro River basin, Brazilian Amazon. The specimens were captured for one day each month, in October to November 2016, early in the morning and early evening, usi...

Zootechnical indices and digestibility in juveniles of tambaqui Colossoma macropomum fed a diet containing particulate maize

Braz. j. biol; 82 (), 2022
Three experiments were done with different particle sizes of corn feed on its zootechnical performance, passing rate and apparent digestibility of juvenile tambaqui (Colossoma macropomum). In the first, 200 juveniles were used and distributed in 20 tanks (220 L), 10 fish per unit (four replicates). The e...

New records of the occurrence of Megaleporinus macrocephalus (Garavello & Britski, 1988) (Characiformes, Anostomidae) from the basins of the Itapecuru and Mearim rivers in Maranhão, Northeastern Brazil

Braz. j. biol; 82 (), 2022
The "piaussu", Megaleporinus macrocephalus is an anostomatid fish species native to the basin of the Paraguay River, in the Pantanal biome of western Brazil. However, this species has now been recorded in a number of other drainages, including those of the upper Paraná, Uruguay, Jacuí, Doce, Mucuri, an...

Parasites and diet of Serrasalmus maculatus in a hydroelectric reservoir in Brazil

Abstract Serrasalmus maculatus is a species of piranha which, despite being abundant in a reservoir environment, has few studies related to its parasitological and diet aspects. Thus, we aimed to document the parasitic fauna and diet of the S. maculatus in a hydroelectric reservoir in Brazil. In addition...

Endoparasite diversity and liver alterations in Hoplerythrinus unitaeniatus and Cichlasoma bimaculatum in a quilombola area in Maranhão, Brazil

Our aim was to assess endoparasite diversity and liver alterations in Hoplerythrinus unitaeniatus (jeju) and Cichlasoma bimaculatum (acará preto) in a quilombola area in Maranhão, Brazil. For this, 21 H. unitaeniatus and 21 C. bimaculatum were caught in a natural environment and transported to a labora...

Impact of a large dam on reproduction of a non-migratory teleost species, Acestrorhynchus lacustris (Characiformes: Acestrorhynchidae)

Braz. j. biol; 82 (), 2022
The release of water from the reservoir hypolimnion, lower concentration of oxygen and the anthropogenic regulation of the river flow, could affect the reproduction of fish, especially migratory species. However, little is known about the effects of these changes in water on non-migratory species. In thi...

Tracking the evolutionary pathways among Brazilian Lebiasina species (Teleostei: Lebiasinidae): a chromosomal and genomic comparative investigation

Neotrop. ichthyol; 20 (1), 2022
Despite several difficulties in chromosomal analyses of small-sized fishes, the cytogenetics of the Lebiasinidae was largely improved in the last years, showing differential patterns in the chromosomal evolution inside the family. In this context, it has been shown that genus Lebiasina preserves its kary...