Document Detail

The dive response redefined: underwater behavior influences cardiac variability in freely diving dolphins.
MedLine Citation:
PMID:  22837445     Owner:  NLM     Status:  In-Data-Review    
A hallmark of the dive response, bradycardia, promotes the conservation of onboard oxygen stores and enables marine mammals to submerge for prolonged periods. A paradox exists when marine mammals are foraging underwater because activity should promote an elevation in heart rate (f(H)) to support increased metabolic demands. To assess the effect of the interaction between the diving response and underwater activity on f(H), we integrated interbeat f(H) with behavioral observations of adult bottlenose dolphins diving and swimming along the coast of the Bahamas. As expected for the dive response, f(H) while resting during submergence (40±6 beats min(-1)) was significantly lower than f(H) while resting at the water surface (105±8 beats min(-1)). The maximum recorded f(H) (f(H,max)) was 128±7 beats min(-1), and occurred during post-dive surface intervals. During submergence, the level of bradycardia was modified by activity. Behaviors such as simple head bobbing at depth increased f(H) by 40% from submerged resting levels. Higher heart rates were observed for horizontal swimming at depth. Indeed, the dolphins operated at 37-58% of their f(H,max) while active at depth and approached 57-79% of their f(H,max) during anticipatory tachycardia as the animals glided to the surface. f(H) was significantly correlated with stroke frequency (range=0-2.5 strokes s(-1), r=0.88, N=25 dives) and calculated swim speed (range=0-5.4 m s(-1), r=0.88, N=25 dives). We find that rather than a static reflex, the dive response is modulated by behavior and exercise in a predictable manner.
Shawn R Noren; Traci Kendall; Veronica Cuccurullo; Terrie M Williams
Related Documents :
230405 - Urinary cyclic amp and cyclic gmp in normal and asthmatic subjects during exercise.
17405165 - Active ammonia excretion in the giant mudskipper, periophthalmodon schlosseri (pallas),...
12808165 - Urinary excretion of the uraemic toxin p-cresol in the rat: contribution of glucuronida...
23982155 - Mitochondrial and performance adaptations to exercise training in mice lacking skeletal...
17447715 - Hematocrit change in tropical scuba divers.
1983005 - Efficacy and safety of ibopamine in congestive heart failure.
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Journal of experimental biology     Volume:  215     ISSN:  1477-9145     ISO Abbreviation:  J. Exp. Biol.     Publication Date:  2012 Aug 
Date Detail:
Created Date:  2012-07-27     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0243705     Medline TA:  J Exp Biol     Country:  England    
Other Details:
Languages:  eng     Pagination:  2735-41     Citation Subset:  IM    
Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Center for Ocean Health, 100 Shaffer Road, Santa Cruz, CA 95060, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Electronic individual identification of zebrafish using radio frequency identification (RFID) microt...
Next Document:  Dietary protein level affects iridescent coloration in Anna's hummingbirds, Calypte anna.