Friday, May 15, 2015

[Ichthyology • 2015] Whole-Body Endothermy in A Mesopelagic Fish, the Opah, Lampris guttatus

An opah Lampris guttatus photographed near San Clemente Island off the southern California coast.
photograph: Ralph Pace |

Endothermy (the metabolic production and retention of heat to warm body temperature above ambient) enhances physiological function, and whole-body endothermy generally sets mammals and birds apart from other animals. Here, we describe a whole-body form of endothermy in a fish, the opah (Lampris guttatus), that produces heat through the constant “flapping” of wing-like pectoral fins and minimizes heat loss through a series of counter-current heat exchangers within its gills. Unlike other fish, opah distribute warmed blood throughout the body, including to the heart, enhancing physiological performance and buffering internal organ function while foraging in the cold, nutrient-rich waters below the ocean thermocline.

Nicholas C. Wegner, Owyn E. Snodgrass, Heidi Dewar and John R. Hyde. 2015. Whole-Body Endothermy in A Mesopelagic Fish, the Opah, Lampris guttatus. Science. 348(6236); 786-789 DOI: 10.1126/science.aaa8902

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