Document Detail

Oxygen uptake, diffusion limitation, and diffusing capacity of the bipectinate gills of the abalone, Haliotis iris (Mollusca: Prosobranchia).
MedLine Citation:
PMID:  16448833     Owner:  NLM     Status:  MEDLINE    
Extant abalone retain an ancestral system of gas exchange consisting of paired bipectinate gills. This paper examines the hypothesis that fundamental inefficiencies of this arrangement led to the extensive radiation observed in prosobranch gas exchange organs. Oxygen uptake at 15 degrees C was examined in the right gill of resting adult blackfoot abalone, Haliotis iris Martyn 1784. Pre- and post-branchial haemolymph and water were sampled and oxygen content, partial pressure (Po2), pH, and haemocyanin content measured; in vivo haemolymph flow rate was determined by an acoustic pulsed-Doppler flowmeter. During a single pass across the gills, mean seawater Po2 fell from 138.7 Torr to 83.4 Torr, while haemolymph Po2 rose from 37.2 Torr to 77.0 Torr raising total O2 content from 0.226 to 0.346 mmol L(-1). Haemolymph flowed through the right gill at a mean rate of 9.6 mL min(-1) and carried 0.151 to 0.355 mmol L(-1) of haemocyanin (mean body mass 421 g). Only 34.7% of the oxygen carried in the arterial haemolymph was taken up by the tissues and less than half of this was contributed by haemocyanin. A diffusion limitation index (Ldiff) of 0.47-0.52, a well-matched ventilation-perfusion ratio (1.2-1.4) and a diffusing capacity (D) of 0.174 micromol O2 kg(-1) Torr(-1) indicate that the gills operate efficiently and are able to meet the oxygen requirements of the resting abalone.
Norman L C Ragg; H Harry Taylor
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2006-01-31
Journal Detail:
Title:  Comparative biochemistry and physiology. Part A, Molecular & integrative physiology     Volume:  143     ISSN:  1095-6433     ISO Abbreviation:  Comp. Biochem. Physiol., Part A Mol. Integr. Physiol.     Publication Date:  2006 Mar 
Date Detail:
Created Date:  2006-02-28     Completed Date:  2006-05-04     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  9806096     Medline TA:  Comp Biochem Physiol A Mol Integr Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  299-306     Citation Subset:  IM    
School of Biological Sciences, University of Canterbury, Private Bag 2400 Christchurch, New Zealand.
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MeSH Terms
Blood Flow Velocity
Gastropoda / physiology*
Gills / physiology*
Heart Rate
Hemocyanin / metabolism
Hemolymph / metabolism
Hydrogen-Ion Concentration
Oxygen / blood
Oxygen Consumption*
Partial Pressure
Ventilation-Perfusion Ratio
Reg. No./Substance:
7782-44-7/Oxygen; 9013-72-3/Hemocyanin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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