1. Dogfish were acclimated to 7, 12 or 17 degrees C and exposed to progressive hypoxia at the temperature to which they had been acclimated. During normoxia, the Q10 values for oxygen uptake, heart rate, cardiac output and respiratory frequency over the full 10 degrees C range were: 2.1, 2.1, 2.1 and 2.5 respectively. Increased acclimation temperature had no effect on cardiac stroke volume or systemic vascular resistance, although there was a decrease in branchial vascular resistance, pHa and pHv. 2. Progressive hypoxia had no effect on heart rate or oxygen uptake at 7 degrees C, whereas at 12 degrees C and 17 degrees C there was bradycardia, and a reduction in O2 uptake, with the critical oxygen tension for both variables being higher at the higher temperature. Cardiac stroke volume increased during hypoxia at each temperature, such that cardiac output did not change significantly at 12 and 17 degrees C. Neither pHa nor pHv changed significantly during hypoxia at any of the three temperatures. 3. The influence of acclimation temperatures on experimental results from poikilotherms is pointed out. Previously-published results show quantitative differences. 4. The significance of the present results with respect to the functioning and location of oxygen receptors is discussed. It is argued that as the metabolic demand and critical oxygen tension of the whole animal are increased at high acclimation temperatures the same must be the case with the oxygen receptor. This would raise the stimulation threshold and could account for the bradycardia seen during hypoxia becoming manifest at higher values of PI,O2, Pa,O2 and Pv,O2 as the acclimation temperature is raised.
The effect of progressive hypoxia on respiration in the dogfish (scyliorhinus canicula) at different seasonal temperatures
P. J. Butler, E. W. Taylor; The effect of progressive hypoxia on respiration in the dogfish (scyliorhinus canicula) at different seasonal temperatures. J Exp Biol 1 August 1975; 63 (1): 117–130. doi: https://doi.org/10.1242/jeb.63.1.117
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Meet the JEB Editors @ SEB 2023
Come and meet the JEB team at the Society for Experimental Biology centenary conference from 4-7 July in Edinburgh, UK. Visit exhibition stand 13/15 to pick up JEB centenary goodies, including our new ‘100 years of discovery’ T shirt, and join our Meet the JEB Editors event on Thursday 6 July at 12.30 at Platform 5 to find out more about the journal and chat to Editors including EiC Craig Franklin, Monitoring Editors Sanjay Sane, Trish Schulte and John Terblanche and the in-house News and Reviews team.
New funding schemes for junior faculty staff
In celebration of our 100th anniversary, JEB has launched two new grants to support junior faculty staff working in animal comparative physiology and biomechanics who are within five years of setting up their first lab/research group. Check out our ECR Visiting Fellowships and Research Partnership Kickstart Travel Grants. First deadline for applications is 15 July 2023.
JEB@100: an interview with Monitoring Editor Katie Gilmour
Katie Gilmour tells us how she first encountered the JEB Editorial team as a graduate student at the University of Cambridge, UK, and how she would like to have a Star Trek tricorder to monitor fish non-invasively in the field.
The Forest of Biologists
The Forest of Biologists is a biodiversity initiative created by The Company of Biologists, with support from the Woodland Trust. For every Research and Review article published in Journal of Experimental Biology a native tree is planted in a UK forest. In addition to this we are protecting and restoring ancient woodland and are dedicating these trees to our peer reviewers. Visit our virtual forest to learn more.
Centenary Review - Adaptive echolocation behavior
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Crucial DNA at crux of insect wing size evolution
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