Assessing niche width of endothermic fish from genes to ecosystem.

Journal Article (Journal Article)

Endothermy in vertebrates has been postulated to confer physiological and ecological advantages. In endothermic fish, niche expansion into cooler waters is correlated with specific physiological traits and is hypothesized to lead to greater foraging success and increased fitness. Using the seasonal co-occurrence of three tuna species in the eastern Pacific Ocean as a model system, we used cardiac gene expression data (as a proxy for thermal tolerance to low temperatures), archival tag data, and diet analyses to examine the vertical niche expansion hypothesis for endothermy in situ. Yellowfin, albacore, and Pacific bluefin tuna (PBFT) in the California Current system used more surface, mesopelagic, and deep waters, respectively. Expression of cardiac genes for calcium cycling increased in PBFT and coincided with broader vertical and thermal niche utilization. However, the PBFT diet was less diverse and focused on energy-rich forage fishes but did not show the greatest energy gains. Ecosystem-based management strategies for tunas should thus consider species-specific differences in physiology and foraging specialization.

Full Text

Duke Authors

Cited Authors

  • Madigan, DJ; Carlisle, AB; Gardner, LD; Jayasundara, N; Micheli, F; Schaefer, KM; Fuller, DW; Block, BA

Published Date

  • July 2015

Published In

Volume / Issue

  • 112 / 27

Start / End Page

  • 8350 - 8355

PubMed ID

  • 26100889

Pubmed Central ID

  • PMC4500250

Electronic International Standard Serial Number (EISSN)

  • 1091-6490

International Standard Serial Number (ISSN)

  • 0027-8424

Digital Object Identifier (DOI)

  • 10.1073/pnas.1500524112


  • eng