Results 31 to 40 of about 140 (104)

Description of the Early Development of Hoplias intermedius (Günther, 1864) (Characiformes: Erythrinidae). [PDF]

open access: yesJ Morphol
This study provides the first description of the early development of Hoplias intermedius (Characiformes: Erythrinidae), from the embryonic to the juvenile stage. The morphological, meristic, and morphometric characterization contributes to understanding the ontogeny and developmental transitions of Neotropical fishes, supporting taxonomy, conservation,
de Souza MBV, Volpato RS, Bialetzki A.
europepmc   +2 more sources

A new endemic pearl cichlid of the 'Geophagus' brasiliensis (Cichliformes: Cichlidae) species group from the Piranga River, upper Doce River basin, southeastern Brazil. [PDF]

open access: yesJ Fish Biol
Abstract A new species of pearl cichlid of the ‘Geophagus’ brasiliensis species group, endemic to the Piranga River, a major tributary of the upper Doce River basin in the state of Minas Gerais, southeastern Brazil, is herein described. The new species is delimited using an integrative approach, with molecular‐based species delimitation methods coupled
de Assis CE   +7 more
europepmc   +2 more sources

Oxygen consumption from air and water, ammonia and urea-N excretion, and Na<sup>+</sup> fluxes during progressive aquatic hypoxia in Amazonian armoured catfish Pterygoplichthys gibbiceps and Pterygoplichthys pardalis. [PDF]

open access: yesJ Fish Biol
Abstract The Amazonian loricariid fish Pterygoplichthys gibbiceps, from the Rio Negro, and Pterygoplichthys pardalis, from the Rio Solimões, are facultative air‐breathers that can use the stomach as an air‐breathing organ. Measurement of oxygen uptake under progressive aquatic hypoxia revealed a relatively high hypoxia resistance of both species.
Pelster B, Wood CM, Val AL.
europepmc   +2 more sources

Hydrological Connectivity Enhances Fish Biodiversity in Amazonian Mining Ponds: Insights From eDNA and Traditional Sampling. [PDF]

open access: yesMol Ecol
ABSTRACT Artisanal and small‐scale gold mining (ASGM) expansion in the Madre de Dios region of the Peruvian Amazon has transformed primary forests into a novel wetland complex of thousands of abandoned mining ponds. Despite their ecological relevance, post‐mining recovery of these systems remains understudied, particularly regarding fish biodiversity ...
Timana-Mendoza C   +7 more
europepmc   +2 more sources

Nitrogen excretion and oxygen consumption under severe hypoxia in siluriform fishes from the Amazon. [PDF]

open access: yesJ Fish Biol
Abstract Siluriform fishes collected from the Rio Negro and Rio Solimões proved to be highly resistant to aquatic hypoxia. In all four species analysed in this study, aquatic oxygen consumption significantly decreased from normoxic levels at water PO2 values near 1 kPa. Air‐breathing activity was observed only in Sturisoma sp. (Rio Negro).
Pelster B, Wood CM, Val AL.
europepmc   +2 more sources

Using the swimbladder as a respiratory organ and/or a buoyancy structure—Benefits and consequences

open access: yesJournal of Experimental Zoology Part A: Ecological and Integrative Physiology, Volume 335, Issue 9-10, Page 831-842, November 1, 2021., 2021
Graphical abstract Abstract A swimbladder is a special organ present in several orders of Actinopterygians. As a gas‐filled cavity it contributes to a reduction in overall density, but on descend from the water surface its contribution as a buoyancy device is very limited because the swimbladder is compressed by increasing hydrostatic pressure.
Bernd Pelster
wiley   +1 more source

Comparative histology in the liver and spleen of three species of freshwater teleost

open access: yesNeotropical Ichthyology, 2017
We describe and compare the histology of liver and spleen ofGeophagus brasiliensis (Perciformes), Hypostomus francisci (Siluriformes) and Hoplias aff. malabaricus (Characiformes), tropical freshwater fishes. InG. brasiliensisandH. aff.
Camila F. Sales   +6 more
doaj   +1 more source

Aquatic and Terrestrial Invertebrates Support Fish Assemblages of Amazonian Streams

open access: yesFreshwater Biology, Volume 71, Issue 5, May 2026.
ABSTRACT The Amazonian stream network is remarkable not only for its extent but also for its rich fish diversity. These streams are interconnected with the surrounding forests. However, key ecological aspects of Amazonian freshwater ecosystems, such as energy flows and carbon sources sustaining fish assemblages, remain poorly understood. In this study,
Pedro H. S. Basilio   +14 more
wiley   +1 more source

Effects of flooding regime on the feeding activity and body condition of piscivorous fish in the Upper Paraná River floodplain Efeitos do regime de cheias sobre a atividade alimentar e condição corporal de peixes piscívoros na planície de inundação do Alto Rio Paraná

open access: yesBrazilian Journal of Biology, 2009
Flood pulses affect floodplain enrichment via the incorporation of nutrients and terrestrial biomass. As a result, they positively affect the body condition of aquatic organisms.
KDG. Luz-Agostinho   +4 more
doaj   +1 more source

Anthropogenic Factors Drive the Depletion of Fish Functional Β Diversity Within and Outside Two National Reserves in the Peruvian Amazon

open access: yesAquatic Conservation: Marine and Freshwater Ecosystems, Volume 35, Issue 12, December 2025.
ABSTRACT Understanding the impact of human activities on fish communities is critical for the effective conservation of Amazonian ecosystems. In this study, we sampled environmental DNA (eDNA) from 17 sites (lakes and rivers) in two Peruvian national reserves, Pacaya‐Samiria and Allpahuayo‐Mishana, using a metabarcoding approach with four genetic ...
B. Prat   +6 more
wiley   +1 more source

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