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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1992-10-2
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pubmed:abstractText |
We have investigated structure and function of the external gill filaments, which occur transiently in the embryonic little skate, Raja erinacea. Approximately 25-30 days after spawning (body mass 0.03-0.05 g) external gill filaments appear as an outgrowth from the caudal side of the gill arches. These filaments are thread-like, each containing one afferent and one efferent blood vessel, and by day 70-75 (body mass 0.4-0.5 g) they reach their maximum size at a length of about 1 cm and a blood vessel diameter of 70-80 microns. Subsequent resorption of the filaments is characterized by a decrease in both length and diameter of the blood vessel. By day 90-95 (body mass 0.9-1.0 g) the external gill filaments are completely resorbed and replaced by internal gills. Blood velocity, measured in these external filaments, increased with development from 0.1 mm.sec-1 to about 0.7 min.sec-1, and decreased again during resorption. Blood flow, calculated therefrom with blood vessel diameter, showed a similar maximum curve. A model analysis supports the hypothesis that in a full grown filament respiratory gas exchange is mainly perfusion-limited and can contribute significantly to the total oxygen uptake of the embryo. Analysis of the results indicates, however, that the gill filaments are not adequate as a gas exchange organ for later developmental stages.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:status |
MEDLINE
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pubmed:month |
Jul
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pubmed:issn |
0034-5687
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
89
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1-13
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pubmed:dateRevised |
2009-11-11
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pubmed:meshHeading |
pubmed-meshheading:1518982-Animals,
pubmed-meshheading:1518982-Blood Flow Velocity,
pubmed-meshheading:1518982-Blood Pressure,
pubmed-meshheading:1518982-Gills,
pubmed-meshheading:1518982-Larva,
pubmed-meshheading:1518982-Microscopy, Electron, Scanning,
pubmed-meshheading:1518982-Pulmonary Gas Exchange,
pubmed-meshheading:1518982-Skates (Fish)
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pubmed:year |
1992
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pubmed:articleTitle |
Structure and function of the external gill filaments of embryonic skates (Raja erinacea).
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pubmed:affiliation |
Department of Zoology, University of Massachusetts, Amherst.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
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