Results: 80

Myxobolus sp. (Myxozoa; Myxosporea) causing asymptomatic parasitic gill disease in Astyanax aff. bimaculatus (Characiformes; Characidae) in the Tocantins river basin, amazon region, Brazil

Abstract The middle course of the Tocantins river is located in the eastern portion of the "Legal Amazon" region of Brazil and the Dantas river is one of its tributaries. Among the components of the aquatic biota, eukaryote microparasites establish direct relationships with several species of fish and ha...

Effect of photoperiod on ovarian maturation in Cheirodon interruptus (Teleostei: Characidae)

Braz. j. biol; 79 (4), 2019
Abstract Cheirodon interruptus is a ubiquitous small characid that inhabits the Pampean region and commonly used as bait. Its vast market is supplied from the wild population causing a significant environmental impact. In this study, we assess the effect of photoperiod on ovarian maturation in order to e...

Reproductive biology of pequira Bryconamericus stramineus (Eigenmann, 1908) in Funil Reservoir-MG, Brazil

Braz. j. biol; 79 (4), 2019
Abstract In order to evaluate aspects of reproductive biology of the "pequira" ( Bryconamericus stramineus) in the elevator of the Funil Dam - MG, fish capture was carried out from November 2008 to January 2009 and 317 individuals were collected. The mean standard length (SL) of the population was 4.96 ...

Digestibilidade aparente do farelo de palmiste em tambaqui (Colossoma macropomum)

O objetivo deste trabalho foi determinar a digestibilidade do farelo de palmiste (Elaeis guineensis) para o tambaqui (Colossoma macropomum), em duas classes de peso: 1 (210 alevinos de 4,45±1,18g) e 2 (54 juvenis de 115,91±4,01g). Os coeficientes de digestibilidade aparente (CDA) da matéria seca, prot...

Exposição crônica ao cloridrato de metformina e à glibenclamida causa alterações comportamentais, glicêmicas e de mortalidade em Hemigrammus caudovittatus e Danio rerio

Hemigrammus caudovittatus e Danio rerio foram expostos aos hipoglicemiantes orais (HOs) cloridrato de metformina a 40µg/L e 120µg/L e glibenclamida a 0,13µg/L e 0,39µg/L durante 100 dias. Foram avaliados os efeitos tóxicos dos fármacos em relação ao peso, ao comportamento animal, à glicemia e à...

Reproductive biology of Hyphessobrycon eques (Characiformes: Characidae) in Southern Pantanal, Brazil

Braz. j. biol; 79 (1), 2019
Abstract Population and reproductive aspects allow the knowledge and understanding of population dynamics and the influence of environmental factors, in addition to ensure the success of a species continuity. Thus, the aim of this study was to analyze population and reproductive traits of the species Hyp...

An ultrastructural approach for gill responses after pollutants exposure

Int. j. morphol; 37 (1), 2019
SUMMARY: Morphological and physiological responses of gills exposed to environmental contaminants are widely described in the literature. Among the primary findings are the lamellar fusion, hyperplasia, aneurysms, proliferation of mitochondria-rich cells and mucous cells. This work has as main objectives...

Geographic variation of Moenkhausia bonita (Characiformes: Characidae) in the rio de la Plata basin, with distributional comments on M. intermedia

Neotrop. ichthyol; 17 (1), 2019
Moenkhausia bonita occurs in numerous additional localities from the Bermejo, Paraná, Paraguay, and Uruguay river basins. Given that this finding greatly expands the distributional range of M. bonita, we carried out an intraspecific comparison, using multivariate methods for 18 morphometric and eight me...

Cytogenetic markers as tools in delimiting species of the highly diverse Neotropical fish Bryconamericus (Characiformes: Characidae)

Neotrop. ichthyol; 17 (3), 2019
Bryconamericus is a highly diverse group of characid fishes, being cytogenetic a valuable tool for the delimitation of species. Bryconamericus aff. iheringii (Upper Uruguay/Lower Paraná), B. coeruleus (Upper Paraná), B. cf. ecai e B. cf. eigenmanni (Upper Uruguay) were studied cytogenetically, and pres...

A new species of Astyanax (Characiformes: Characidae) from the rio de Contas basin, Bahia, Brazil

Neotrop. ichthyol; 17 (3), 2019
A new species of Astyanax from tributaries of the rio de Contas, Bahia, Brazil, is described. The new species differs from congeners by having three horizontal series of scales from lateral line to pelvic-fin origin and the distal margin of third infraorbital distinctly separated from vertical and horizo...