Results 131 to 140 of about 84,077 (281)

Oxygen consumption from air and water, ammonia and urea‐N excretion, and Na+ fluxes during progressive aquatic hypoxia in Amazonian armoured catfish Pterygoplichthys gibbiceps and Pterygoplichthys pardalis

open access: yesJournal of Fish Biology, EarlyView.
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.
Bernd Pelster   +2 more
wiley   +1 more source

Nitrogen excretion and oxygen consumption under severe hypoxia in siluriform fishes from the Amazon

open access: yesJournal of Fish Biology, EarlyView.
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).
Bernd Pelster   +2 more
wiley   +1 more source

Oocyte structure and ultrastructure in the Mexican silverside fish Chirostoma humboldtianum (Atheriniformes: Atherinopsidae)

open access: yesRevista de Biología Tropical, 2008
the structural and ultrastructural features of gonads from endemic Mexican fish have received scarce attention. This study describes the histological and ultrastructural characteristics of the oocyte in Chirostoma humboldtianum. The ovary is asynchronic,
Rodolfo Cárdenas   +5 more
doaj  

Giants in the cold: Morphological evidence for vascular heat retention in the viscera but not the skeletal muscle of the basking shark (Cetorhinus maximus)

open access: yesJournal of Fish Biology, EarlyView.
Abstract Fewer than 50 of the over 30,000 extant species of fishes have developed anatomical specializations facilitating endothermy in specific body regions. The plankton‐feeding basking shark (Cetorhinus maximus), traditionally classified as an ectotherm, was recently shown to have regionally endothermic traits such as centralized red muscle (RM ...
C. Antonia Klöcker   +9 more
wiley   +1 more source

Differential Cellular Response to Mercury in Non-Farmed Fish Species Based on Mitochondrial DNA Copy Number Variation Analysis

open access: yesBiology
Mercury (Hg) pro-oxidant role on biological systems and its biogeochemical cycle represent a serious threat due to its persistence in marine environment.
Marta Giuga   +6 more
doaj   +1 more source

Pinopsin Regulates Melatonin Production and Daily Locomotor Activity: Functional Insights From Gene-Edited Xenopus Tadpoles. [PDF]

open access: yesJ Pineal Res
ABSTRACT Circadian rhythm alignment depends on environmental light detection via opsins. Pinopsin, originally identified in the pineal organ of birds and later in amphibian pineal complex and eyes, may play a role in this process, though its function has not been genetically tested.
Heshami N   +4 more
europepmc   +2 more sources

Branchial localization of acid (A‐type) and base (B‐type) excreting ionocytes in Amazonian stenohaline freshwater Potamotrygon ray

open access: yesJournal of Fish Biology, EarlyView.
Abstract The branchial epithelium of Potamotrygon—a member of the only strictly freshwater elasmobranch family Potamotrygonidae—was observed via immunohistochemistry, and two distinct forms of ionocytes were identified. The acid (A‐type) and base (B‐type) secreting cells with respective basolateral–apical localizations of Na+/K+‐ATPase–Na+/H+ exchanger
M. W. Rossi   +3 more
wiley   +1 more source

Body size of male Atlantic salmon (Salmo salar L.) at introduction of a 5‐week LD12:12 winter signal influences their decision to mature early or smoltify

open access: yesJournal of Fish Biology, EarlyView.
Abstract Sexual maturation of male Atlantic salmon post‐smolts (‘jacking’) is undesired in aquaculture and seems to occur due to the intensification in modern facilities. Maturation depends on internal and external factors (temperature, photoperiod, feed availability, energy levels, body size, genetic background) that act on the brain‐pituitary‐gonad ...
Enrique Pino‐Martinez   +5 more
wiley   +1 more source

Newly discovered and conserved role of IgM against viral infection in an early vertebrate

open access: yeseLife
IgM emerged in jawed vertebrates 500 Mya and remains the most evolutionarily conserved antibody class. However, despite extensive studies on IgM as an ancient antiviral weapon in warm-blooded vertebrates, its role and mechanisms in combating viral ...
Weiguang Kong   +9 more
doaj   +1 more source

Expression of corticoid‐regulatory genes in the gills of Atlantic salmon (Salmo salar) parr and smolt and during salinity acclimation

open access: yesJournal of Fish Biology, EarlyView.
Abstract In teleost fishes, cortisol is the major corticoid and has both glucocorticoid and mineralocorticoid actions. However, how fish tissues discriminate between these distinct corticosteroid actions is unclear. In mammals, the major factors responsible for intracellular corticosteroid regulation are glucocorticoid receptors (grs) and the ...
Makoto Kusakabe   +4 more
wiley   +1 more source

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