1.
Science
; 310(5745): 104-6, 2005 Oct 07.
Artigo
em Inglês
| MEDLINE
| ID: mdl-16210538
RESUMO
Shark populations are declining globally, yet the movements and habitats of most species are unknown. We used a satellite tag attached to the dorsal fin to track salmon sharks (Lamna ditropis) for up to 3.2 years. Here we show that salmon sharks have a subarctic-to-subtropical niche, ranging from 2 degrees to 24 degrees C, and they spend winter periods in waters as cold as 2 degrees to 8 degrees C. Functional assays and protein gels reveal that the expression of excitation-contraction coupling proteins is enhanced in salmon shark hearts, which may underlie the shark's ability to maintain heart function at cold temperatures and their niche expansion into subarctic seas.