IAB Research Project Description

Collaborative Research: Linkages Among Mitochondrial Form, Function and Thermal Tolerance of Antarctic Notothenioid Fishes

Kristin O'Brien, assistant professor of biology and wildlife, stands on deck in Dallman Bay west of the Antarctic Peninsula. O'Brien studies the unique physiological traits that have evolved in Antarctic fishes living in the chronically cold environment of the Southern Ocean. Credit: Photo courtesy/Kristin O'Brien.

Credit: Photo courtesy/Kristin O'Brien.

Credit: Photo courtesy/Kristin O'Brien.

Credit: Photo courtesy/Kristin O'Brien.

Any and all uses of these images must include photographer credit.

Waters surrounding the Antarctic continent are unlike any other: isolated, chronically cold, well-oxygenated and low in species competition.

Within this remarkable environment, the notothenioid fishes have evolved many unusual physiological traits. One of the most notable characteristics is the complete absence of the circulating oxygen-binding protein, hemoglobin (Hb) within the Channichthyid (Icefish) family of notothenioids. Moreover, some species within the 16 members of this family have also lost the ability to express the oxygen-binding and storage protein, myoglobin (Mb) in cardiac muscle.

Our previous work has determined that the loss of Hb and/or Mb is correlated with significant increases in densities of mitochondria within oxidative tissues and extensive remodeling of these vital organelles.

To date, nothing is known about how modifications in mitochondrial architecture of icefishes affect organelle function, or more importantly, how they affect organismal-level physiology. Mitochondria are essential for producing ATP through the process of oxidative phosphorylation and overwhelming evidence indicates that changes in mitochondrial structure and function impact organismal biology. Most critical for Antarctic fishes is that mitochondrial characteristics have been linked to how well ectotherms can withstand increases in temperature.

Our collaborative research project will address the hypothesis that the unusual mitochondrial architecture of Antarctic Channichthyids has led to changes in function that impact their ability to withstand elevations in temperature. This work holds intellectual merit, because results may establish channichthyid icefishes as a sentinel taxon for signaling the impact of global warming on the Southern Ocean.

Project Funding

National Science Foundation
1 Sep 2008 – 31 Aug 2011
IAB Proposal #07-096
UAF Grant #G5064
IAB Project #152

Outreach & Media

News and Outreach Articles

  • Kristin O’Brien: Antarctic icefishes have translucent bodies and blood
    [ link | pdf ]

Media Contact

Marie Thoms
Communications/Web Manager
Institute of Arctic Biology
302A Irving I
University of Alaska Fairbanks
Fairbanks, AK 99775-7000
email: methoms@alaska.edu
phone: 907.474.7412