{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T13:17:00Z","timestamp":1791465420150,"version":"4.3.4"},"reference-count":39,"publisher":"The Company of Biologists","issue":"5","license":[{"start":{"date-parts":[[2024,3,5]],"date-time":"2024-03-05T00:00:00Z","timestamp":1709596800000},"content-version":"vor","delay-in-days":4,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/501100002241","name":"Japan Science and Technology Agency","doi-asserted-by":"crossref","award":["JPMJSP2108"],"award-info":[{"award-number":["JPMJSP2108"]}],"id":[{"id":"10.13039\/501100002241","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"crossref","award":["22H05648"],"award-info":[{"award-number":["22H05648"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"crossref","award":["22K21355"],"award-info":[{"award-number":["22K21355"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100004721","name":"University of Tokyo","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100004721","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2024,3,1]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:p>Air-breathing vertebrates exhibit cardiovascular responses to diving including heart rate reduction (diving bradycardia). Field studies on aquatic mammals and birds have shown that the intensity of bradycardia can vary depending on diving behaviour, such as the depth of dives and dive duration. However, in aquatic reptiles, the variation in heart rate during deep dives under natural conditions has not been fully investigated. In this study, we released five loggerhead sea turtles (Caretta caretta) outfitted with recorders into the sea and recorded their electrocardiogram, depth, water temperature and longitudinal acceleration. After 3\u00a0days, the recorders automatically detached from the turtles. The heart rate signals were detected from the electrodes placed on the surface of the plastron. The mean (\u00b1s.d.) heart rate of 12.8\u00b14.1\u00a0beats\u00a0min\u20131 during dives was significantly lower than that of 20.9\u00b14.1\u00a0beats\u00a0min\u20131 during surface periods. Heart rate during dives varied with dive depth, although it remained lower than that at the surface. When the turtle dived deeper than 140\u00a0m, despite the relatively high flipper stroke rate (approximately 19\u00a0strokes\u00a0min\u20131), the heart rate dropped rapidly to approximately 2\u00a0beats\u00a0min\u20131 temporarily. The minimum instantaneous heart rate during dives was lower at deeper dive depths. Our results indicate that loggerhead sea turtles show variations in the intensity of diving bradycardia depending on their diving behaviour, similar to that shown by marine mammals and birds.<\/jats:p>","DOI":"10.1242\/jeb.246334","type":"journal-article","created":{"date-parts":[[2024,3,5]],"date-time":"2024-03-05T17:02:04Z","timestamp":1709658124000},"source":"Crossref","is-referenced-by-count":6,"title":["Heart rate reduction during voluntary deep diving in free-ranging loggerhead sea turtles"],"prefix":"10.1242","volume":"227","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5813-455X","authenticated-orcid":false,"given":"Ayaka","family":"Saito","sequence":"first","affiliation":[{"name":"Atmosphere and Ocean Research Institute, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564 , Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0894-5215","authenticated-orcid":false,"given":"Chihiro","family":"Kinoshita","sequence":"additional","affiliation":[{"name":"Atmosphere and Ocean Research Institute, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564 , Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kino","family":"Sakai","sequence":"additional","affiliation":[{"name":"Atmosphere and Ocean Research Institute, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564 , Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katsufumi","family":"Sato","sequence":"additional","affiliation":[{"name":"Atmosphere and Ocean Research Institute, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564 , Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8499-799X","authenticated-orcid":false,"given":"Kentaro Q.","family":"Sakamoto","sequence":"additional","affiliation":[{"name":"Atmosphere and Ocean Research Institute, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564 , Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"237","published-online":{"date-parts":[[2024,3,5]]},"reference":[{"key":"2024030522005449600_JEB246334C1","doi-asserted-by":"publisher","first-page":"1","DOI":"10.18637\/jss.v067.i01","article-title":"Fitting linear mixed effects models using lme4","volume":"67","author":"Bates","year":"2015","journal-title":"J. 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