title: Satellite tagging and cardiac physiology reveal niche expansion in salmon sharks.
abstract: 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.
authors.affiliation: Tuna Research and Conservation Center, Stanford University, Hopkins Marine Station, 120 Oceanview Boulevard, Pacific Grove, CA 93950, USA.
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Weng
authors.forename: Pedro C
authors.initials: PC
authors.lastname: Castilho
authors.forename: Jeffery M
authors.initials: JM
authors.lastname: Morrissette
authors.forename: Ana M
authors.initials: AM
authors.lastname: Landeira-Fernandez
authors.forename: David B
authors.initials: DB
authors.lastname: Holts
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Schallert
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Goldman
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Block
mesh_terms: D000064:Acclimatization; D000823:Animal Identification Systems; D025041:Animal Migration; D000818:Animals; D001522:Behavior, Animal; D001831:Body Temperature; D002118:Calcium / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D003080:Cold Temperature; D017753:Ecosystem; D004777:Environment; D005260:Female; D006321:Heart / Q000502:physiology*; D006352:Heart Ventricles / Q000378:metabolism; D008297:Male; D009200:Myocardial Contraction; D009206:Myocardium / Q000378:metabolism*; D010140:Pacific Ocean; D011235:Predatory Behavior; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism; D012519:Sarcoplasmic Reticulum / Q000378:metabolism; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D017215:Satellite Communications; D012621:Seasons; D012754:Sharks / Q000502:physiology*; D013550:Swimming; D013696:Temperature
chemical_list: D019837:Ryanodine Receptor Calcium Release Channel; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000252:Calcium-Transporting ATPases; D002118:Calcium