These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Crayfish respiration as a function of water oxygenation.
    Author: Dejours P, Beekenkamp H.
    Journal: Respir Physiol; 1977 Jun; 30(1-2):241-51. PubMed ID: 17899.
    Abstract:
    Crayfish, Astacus leptodactylus, for several hours breathed water equilibrated either with a hypoxic gas mixture, or air, or oxygen. The hydrostatic pressure in the right epibranchial cavity was recorded and the left epibranchial water sempled from time to time. The higher the water oxygenation, the less the duration of ventilation, the frequency of the scaphognathite beats which ensure water convection, the negative of the water hydrostatic pressure relative to ambient water pressure, and the respired water flow. The water convection per unit quantity of oxygen consumed decreased by a factor of about 20 when the animal passed from hypoxic water at PO2 of 72 torr to hyperoxic water at PO2 of 697 torr. Prolonged hyperoxia, up to 100 days, results in a hypercapnic acidosis of the prebranchial blood. pH decreased about 0.2 unit, PCO2 increased from 2.5 torr to a value of 6 torr, and [HCO-3] from 6 to a value of 9 meq-L-1. This hypercapnic acidosis remained uncompensated during several weeks exposure to hyperoxia. Observations on the fresh water crayfish, a marine crab, and several species of fish, suggest that in aquatic animals (1) the ventilatory activity depends greatly on the degree of water oxygenation: the higher the water oxygenation, the lower the ventilation; (2) the change of ventilation may be accompanied by a new equilibrium of the blood acid-base status, quite different from that observed in normoxia.
    [Abstract] [Full Text] [Related] [New Search]