Dear MarMamers We would like to share our new open-access publication that investigated how breathing is affecting heart rate. The details about the paper can be found below, and please send me an email if you have any questions. Sincerely, Andreas Title Cardiorespiratory coupling in the bottlenose dolphin (Tursiops truncatus) Authors: A. Fahlman, J. C. Mcknight, A. M. Blawas, N. West, A. G. Torrente, K. Aoki Journal: Frontiers Physiology doi: https://doi.org/10.3389/fphys.2023.1234432 Abstract: Introduction: The bottlenose dolphin (Tursiops truncatus) is an intermittent breather, where the breath begins with an exhalation followed by inhalation and an extended inter-breath interval ranging from 10 to 40 s. Breathing has been shown to alter both the instantaneous heart rate (ifH) and stroke volume (iSV) in the bottlenose dolphin, with a transitory ventilatory tachycardia following the breath, and an exponential decrease to a stable ifH around 40 beats • min−1 during the inter-breath period. As the total breath duration in the dolphin is around 1 s, it is not possible to assess the contribution of exhalation and inhalation to these changes in cardiac function during normal breathing. Methods: In the current study, we evaluated the ifH response by separating expiration and inspiration of a breath, which allowed us to distinguish their respective contribution to the changes in ifH. We studied 3 individual male bottlenose dolphins trained to hold their breath between the different respiratory phases (expiration and inhalation). Results: Our data show that inspiration causes an increase in ifH, while expiration appears to result in a decrease in ifH. Discussion: These data provide improved understanding of the cardiorespiratory coupling in dolphins, and show how both exhalation and inhalation alters ifH.