Use este identificador para citar ou linkar para este item: https://repositorio.inpa.gov.br/handle/1/17338
Título: The transition from water-breathing to air-breathing is associated with a shift in ion uptake from gills to gut: a study of two closely related erythrinid teleosts, Hoplerythrinus unitaeniatus and Hoplias malabaricus
Autor: Wood, Chris M.
Pelster, Bernd
Giacomin, Marina Mussoi
Sadauskas-Henrique, Helen
Almeida-Val, Vera Maria Fonseca
Val, Adalberto Luis
Palavras-chave: Adenosine Triphosphatase (potassium Sodium)
Air
Chloride
Ion
Potassium
Sodium
Animals
Blood
Characiformes
Gill
Hypoxia
Intestines
Intestine Absorption
Metabolism
Physiology
Respiratory Function
Species Difference
Air
Animal
Characiformes
Chlorides
Gills
Hypoxia
Intestinal Absorption
Intestines
Ions
Potassium
Respiratory Physiological Phenomena
Sodium
Sodium-potassium-exchanging Atpase
Species Specificity
Data do documento: 2016
Revista: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology
É parte de: Volume 186, Número 4, Pags. 431-445
Abstract: The evolutionary transition from water-breathing to air-breathing involved not only a change in function of the organs of respiratory gas exchange and N-waste excretion, but also in the organs of ion uptake from the environment. A combination of in vivo and in vitro techniques was used to look at the relative importance of the gills versus the gut in Na+, Cl−, and K+ balance in two closely related erythrinid species: a facultative air-breather, the jeju (Hoplerythrinus unitaeniatus) and an obligate water-breather, the traira (Hopliasmalabaricus). The jeju has a well-vascularized physostomous swimbladder, while that in the traira is poorly vascularized, but the gills are much larger. Both species are native to the Amazon and are common in the ion-poor, acidic blackwaters of the Rio Negro. Under fasting conditions, the traira was able to maintain positive net Na+ and Cl− balance in this water, and only slightly negative net K+ balance. However, the jeju was in negative net balance for all three ions and had lower plasma Na+ and Cl− concentrations, despite exhibiting higher branchial Na+,K+ATPase and v-type H+ATPase activities. In the intestine, activities of these same enzymes were also higher in the jeju, and in vitro measurements of net area-specific rates of Na+, Cl−, and K+ absorption, as well as the overall intestinal absorption capacities for these three ions, were far greater than in the traira. When acutely exposed to disturbances in water O2 levels (severe hypoxia ~15 % or hyperoxia ~420 % saturation), gill ionoregulation was greatly perturbed in the traira but less affected in the jeju, which could “escape” the stressor by voluntarily air-breathing. We suggest that a shift of ionoregulatory capacity from the gills to the gut may have occurred in the evolutionary transition to air-breathing in jeju, and in consequence branchial ionoregulation, while less powerful, is also less impacted by variations in water O2 levels. © 2016, Springer-Verlag Berlin Heidelberg.
DOI: 10.1007/s00360-016-0965-5
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