Dear MARMAM community, On behalf of all the co-authors, we are happy to share our recent publications on electrocardiography in South American pinnipeds and Burmeister porpoises. All inquiries and copies of the papers should be directed to Mariela Dassis (marieladassis@gmail.com). Thank you! Diego Rodríguez Dassis,M., C.de León, A.Díaz, A.Faiella, A.Saubidet, D.Rodríguez, E.Castro. 2022. First description of the Burmeister porpoise (Phocoena spinipinnis) electrocardiogram. J Exp Zool A Ecol Integr Physiol. 2022;1–7. DOI: 10.1002/jez.2641. Abstract The aim of this study was to make the first characterization of the electrocardiogram (ECG) of the Burmeister porpoise (Phocoena sipinipinnis). A total of three ECGs were made in one, wild juvenile female (body weight = 32.5 kg, Lt = 1.45 m), temporarily held in captivity for rehabilitation at Mar del Plata Aquarium (Argentina). For ECG recordings, the animal was removed from its pool on a stretcher under constant veterinary supervision. A traditional six‐lead system in the frontal plane was used, with the typical four “extremities” electrodes positioned bilaterally. ECGs were readable and all waves were detectable. The QRS complexes were characterized by Q wave absence in all leads. The ECG characteristically displayed distinctly defined STs, with a T wave clearly differentiated from the QRS complex. An STs elevation was detected in leads II and III. The mean electrical axis was −79°, meaning a cranial left axis orientation. The animal showed normal sinus rhythm and heart rate (HR) showed a continuous oscillation between tachycardia and bradycardia. Mean HR from all recordings was 147.02 ± 24.95 bpm (range = 71–176, n = 178). Evidence of the occurrence of respiratory sinus arrhythmia was detected through HR variations and RR interval differences, which suggested an adequate cardiovascular system compensation to handling conditions. This study has reported ECG amplitude and duration measurements of a potentially healthy specimen, which represents the starting point for the determination of normal ECG values for this species. Also, it has confirmed that ECG is a valuable noninvasive tool for rapid cardiac health assessment in small cetaceans. Dassis,M., C.de León, A.Díaz, E.Rodríguez, D.Rodríguez, G.Giardino, E.Castro. 2022. Comparative electrocardiogram in two anesthetized pinnipeds, the South American fur seal (Arctocephalus australis) and the Southern sea lion (Otaria byronia), with analysis of ECG parameters allometry. Mar Mam Sci. 2022;1–15. DOI: 10.1111/mms.12915. Abstract The mammalian heart has been described as a highly evolutionarily conserved structure and the cardiovascular system allometry has been fully studied among many mammalian species, but few of these studies have been focused on marine mammals. Previously reported electrocardiogram (ECG) of anesthetized Southern sea lions (SSL; n = 13) and South American fur seals (SAFS; n = 19) females were compared, and linear models were used to examine variations of ECG parameters with body mass (BM) and heart rate (HR). Electrocardiograms resulted in qualitatively similar characteristics (rhythm, polarity patterns, mean electrical axes orientation, and waves/complex forms), but there were significant quantitative differences in HR and all ECG parameters. With few exceptions, duration and amplitude parameters were significantly higher in the SSL, whereas the SAFS had a significantly higher HR. Allometric scaling was verified for most duration variables (P, T, QRS, and PR interval) and P wave amplitude, which were all significantly and positively associated with BM, with no significant effect found for HR. Results suggest that the cardiac conduction system is highly conserved, and allometry occurs for these species even in anesthetized subjects, particularly in atrial contraction and atrioventricular conduction, which was proposed as potentially related to optimal atrioventricular activation sequence and high hemodynamic efficiency. -- Dr.Diego Rodríguez Instituto de Investigaciones Marinas y Costeras, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata-CONICET. Casilla de Correos 1260 (Correo Central) (7600) Mar del Plata, Argentina TE + 54 (0) 223 4754060 (Int.244) FAX +54 (0) 223 4753150 Skype: diego291162 Facebook: http://www.facebook.com/groups/136323163081610/ Website: https://www.researchgate.net/profile/Diego_Rodriguez16 ORCID ID: https://orcid.org/0000-0002-5080-3739 "Si los pueblos no se ilustran, si no se divulgan sus derechos, si cada hombre no conoce lo que puede, vale, debe, nuevas ilusiones sucederán a las antiguas y será tal vez nuestra suerte cambiar de tiranos sin destruir la tiranía" (Mariano Moreno)