Publication
Title
Gill morphology and acute hypoxia : responses of mitochondria-rich, pavement, and mucous cells in the Amazonian oscar (**Astronotus ocellatus**) and the rainbow trout (**Oncorhynchus mykiss**), two species with very different approaches to the osmo-respiratory compromise
Author
Abstract
The hypoxia-intolerant rainbow trout (Oncorhynchus mykiss (Walbaum, 1792)) exhibits increased branchial ion permeability and Na+ influx during acute exposure to moderate hypoxia (Po2 = 80 torr; 1 torr = 133.3224 Pa), manifesting the usual trade-off between gas exchange and electrolyte conservation. In contrast, the hypoxia-tolerant oscar (Astronotus ocellatus (Agassiz, 1831)) is unusual in exhibiting decreased branchial ion permeability to ions and Na+ influx during acute exposure to severe hypoxia (Po2 = 1020 torr). These different physiological approaches to the osmo-respiratory compromise correlate with rapid, oppositely directed changes in gill morphology. In oscar, pavement cells (PVCs) expanded, partially covering neighboring mitochondria-rich cells (MRCs), which were recessed and reduced in size. Those remaining open were transformed from shallow-basin to deep-hole forms with smaller openings, deeper apical crypts, and smaller numbers of subapical microvesicles, changes that were largely reversed during normoxic recovery. In contrast, moderate hypoxia caused outward bulging of MRCs in rainbow trout with increases in size, surface exposure, and number of subapical microvesicles, accompanied by PVC retraction. These changes were partially reversed during normoxic recovery. In both rainbow trout and oscar, hypoxia caused discharge of mucus from enlarged mucous cells (MCs). Rapid, divergent morphological changes play an important role in explaining two very different physiological approaches to the osmo-respiratory compromise.
Language
English
Source (journal)
Canadian journal of zoology. - Ottawa, 1951, currens
Publication
Ottawa : 2011
ISSN
0008-4301
Volume/pages
89:4(2011), p. 307-324
ISI
000291185800006
Full text (Publisher's DOI)
Full text (publisher's version - intranet only)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 22.06.2011
Last edited 27.11.2017
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