The present study was undertaken to elicit the temporal sequence of changes in cardiovascular and respiratory function during aestivation. Twelve lungfish (2-6 kg) equipped with ECG electrodes, arterial and buccal cannulae, were studied while aestivating in mud or in artificial cloth-bag nests. The periods of observation ranged from 0.5 to 9.5 months. The mean arterial blood pressure gradually decreased from control values of 20-28 mm Hg to a range of 14-18 mmHg during the first 30 days of aestivation, whereas the heart rate dropped more gradually (22-30 beats/min to 11-16 beats/min in 6o days). Ventilatory frequency increased 2- to 5-fold during the first 30 days of encystment and then returned to the control range (2-10 h) within 45 days. The arterial PCOCO2 increased from control values of 25-30 mm Hg to 45-70 mmHg; arterial pH decreased concomitantly from 7.55-7.60 to 7.40-7.26 after the cocoon was formed. The arterial POO2 increased from the control range of 25-40 to 50-58 mmHg during the first 10 days and then returned to the control range. Therefore, the sequential cardiopulmonary changes during the onset of aestivation are gradual and do not parallel the decline in oxygen consumption. Aestivating lungfish also respond promptly to sensory disturbances and thus do not appear to be in a deep torpor. Aestivation is pictured as a state of dormancy, gradual in onset, and the consequence of a complicated physiological interplay.
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.
JEB@100: an interview with Monitoring Editor Stuart Egginton
Stuart Egginton reveals how he overcame the challenges of being a comparative physiologist in a medical school and how he would tell his younger self to trust his instincts when pursuing new ideas.
Travelling Fellowships from JEB
Our Travelling Fellowships offer up to £3,000 to graduate students and post-doctoral researchers wishing to make collaborative visits to other laboratories. Next deadline to apply is 27 October 2023
Feedforward and feedback control in the neuromechanics
Auke J. Ijspeert and Monica A. Daley provide an overview of key knowledge gained from comparative vertebrate experiments and insights obtained from neuromechanical simulations and robotic approaches. Read the full Centenary Review Article here.
Light fine-tunes electric fish pulses to keep them in the shade
Weakly electric fish perceive their surroundings through electric chirrups and now Ana Camargo & colleagues have revealed that light fine-tunes the fish's electric pulses to ensure that they remain scheduled beneath the mats of vegetation they use for shelter, avoiding penetrating beams of light that could give them away.
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