Linked Life Data

12024288

Source:http://linkedlifedata.com/resource/pubmed/id/12024288

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2002-5-23
pubmed:abstractText
Oxygen consumption (Mo(2)), heartbeat rate and form, and circulating hemolymph oxygen content were measured in relation to temperature in the large Antarctic infaunal bivalve Laternula elliptica. After elevations in temperature from 0 degrees to 3 degrees, 6 degrees, and then 9 degrees C, Mo(2) and heartbeat rate rose to new levels, whereas maximum circulating hemolymph oxygen content fell. At 0 degrees C, Mo(2) was 19.6 micromol O(2) h(-1) for a standard animal of 2-g tissue ash-free dry mass, which equates to a 8.95-g tissue dry-mass or 58.4-g tissue wet-mass animal. Elevation of metabolism following temperature change had acute Q(10) values between 4.1 and 5, whereas acclimated figures declined from 3.4 (between 0 degrees and 3 degrees C) to 2.2 (3 degrees -6 degrees C) and 1.9 (6 degrees -9 degrees C). Heartbeat rate showed no acclimation following temperature elevations, with Q(10) values of 3.9, 3.2, and 4.3, respectively. Circulating hemolymph oxygen content declined from 0 degrees to 3 degrees and 6 degrees C but stayed at a constant Po(2) (73-78 mmHg) and constant proportion ( approximately 50%) of the oxygen content of the ambient water. At 9 degrees C, Mo(2) and heartbeat rate both peaked at values 3.3 times those measured at 0 degrees C, which may indicate aerobic scope in this species. After these peaks, both measures declined rapidly over the ensuing 5 d to the lowest measured in the study, and the bivalves began to die. Hemolymph oxygen content fell dramatically at 9 degrees C to values between 2% and 12% of ambient water O(2) content and had a maximum Po(2) of around 20 mmHg. These data indicate an experimental upper lethal temperature of 9 degrees C and a critical temperature, where a long-term switch to anaerobic metabolism probably occurs, of around 6 degrees C for L. elliptica. Concurrent measures of mitochondrial function in the same species had indicated strong thermal sensitivity in proton leakage costs, and our data support the hypothesis that as temperature rises, mitochondrial maintenance costs rapidly outstrip oxygen supply mechanisms in cold stenothermal marine species.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1522-2152
pubmed:author
pubmed:issnType
Print
pubmed:volume
75
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
123-33
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:articleTitle
Metabolic demand, oxygen supply, and critical temperatures in the Antarctic bivalve Laternula elliptica.
pubmed:affiliation
National Environment Research Council British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, United Kingdom. l.peck@bas.ac.uk
pubmed:publicationType
Journal Article