QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by BUTLER, P. J. Articles by MCMAHON, B. R. Search for Related Content PubMed Articles by BUTLER, P. J. Articles by MCMAHON, B. R.

Journal of Experimental Biology 73,131-146 (1978)
Published by Company of Biologists 1978

Respiratory and Circulatory Changes in the Lobster (Homarus Vulgaris) During Long Term Exposure to Moderate Hypoxia

P. J. BUTLER ¹, E. W. TAYLOR ¹, and B. R. MCMAHON ²

¹ Department of Zoology and Comparative Physiology, The University of Birmingham Birmingham B15 2TT, U.K.
² Department of Biology, University of Calgary Calgary, Alberta, Canada T2N 1N4.; Department of Zoology and Comparative Physiology, The University of Birmingham Birmingham B15 2TT, U.K.

1. Within a few hours of the lobsters being placed in the experimental chamber in normoxic water (P_o2, 130–135 mmHg), their heart rate, oxygen uptake (V_o2) and ventilation volume (V_u) were relatively high. The scaphognathites were simultaneously active on both sides (bilateral ventilation) for 50% of the time, active on one side only (unilateral ventilation) for 32% of the time and simultaneously inactive (respiratory pause) for 18% of the time. Percentage extraction of O₂ (% Ext.) was relatively low. 48h after having been set up, heart rate, V_O2 and V_g had decreased significantly, % Ext. had increased and bilateral ventilation occupied 25% of the time. Heart rate was low and the beat irregular.

2. Upon subsequent exposure to hypoxia (P_O2, 50–55 mmHg), P_a, O₂, fell, there was initial hyperventilation, bilateral ventilation for 89% of the time, heart beat was more regular but V_o2 did not change significantly. An initial increase in pHa caused the O₂ affinity of the Hey to rise. After 72h exposure to hypoxia V_g and pHa had declined, but V_g was still higher than at the end of the period of normoxia. Blood lactate, V_o2 and % Ext. were not significantly different from the values recorded after 48 h in normoxic water. Upon return to normoxic water, V_g and the time the animals spent ventilating both branchial chambers fell, but V_o2 increased.

3. It is concluded that for settled lobsters, V_o2 could be maintained during moderate hypoxia by increasing V_g maintaining a regular heart beat, and at least initially by increasing the O₂ affinity of the Hey.

This article has been cited by other articles:

				E Stegen and M. Grieshaber Adenosine increases ventilation rate, cardiac performance and haemolymph velocity in the American lobster Homarus americanus J. Exp. Biol., January 3, 2001; 204(5): 947 - 957. [Abstract] [PDF]