Effect of temperature acclimation on red blood cell oxygen affinity in Pacific bluefin tuna (Thunnus orientalis) and yellowfin tuna (Thunnus albacares).

Journal Article (Journal Article)

Hemoglobin-oxygen (Hb-O2) binding properties are central to aerobic physiology, and must be optimized for an animal's aerobic requirements and environmental conditions, both of which can vary widely with seasonal changes or acutely with diving. In the case of tunas, the matter is further complicated by large regional temperature differences between tissues within the same animal. This study investigates the effects of thermal acclimation on red blood cell Hb-O2 binding in Pacific bluefin tuna (T. orientalis) and yellowfin tuna (T. albacares) maintained in captive tanks at acclimation temperatures of 17°, 20° and 24 °C. Oxygen binding properties of acclimated tuna isolated red blood cells were examined under varying experimental temperatures (15°-35 °C) and CO2 levels (0%, 0.5% and 1.5%). Results for Pacific bluefin tuna produced temperature-independence at 17 °C- and 20 °C-acclimation temperatures and significant reverse temperature-dependence at 24 °C-acclimation in the absence of CO2, with instances of reverse temperature-dependence in 17 °C- and 24 °C-acclimations at 0.5% and 1.5% CO2. In contrast, yellowfin tuna produced normal temperature-dependence at each acclimation temperature at 0% CO2, temperature-independence at 0.5% and 1.5% CO2, and significant reverse temperature-dependence at 17 °C-acclimation and 0.5% CO2. Thermal acclimation of Pacific bluefin tuna increased O2 binding affinity of the 17 °C-acclimation group, and produced a significantly steeper oxygen equilibrium curve slope (nH) at 24 °C-acclimation compared to the other acclimation temperatures. We discuss the potential implications of these findings below.

Full Text

Duke Authors

Cited Authors

  • Lilly, LE; Bonaventura, J; Lipnick, MS; Block, BA

Published Date

  • March 2015

Published In

Volume / Issue

  • 181 /

Start / End Page

  • 36 - 44

PubMed ID

  • 25434601

Electronic International Standard Serial Number (EISSN)

  • 1531-4332

International Standard Serial Number (ISSN)

  • 1095-6433

Digital Object Identifier (DOI)

  • 10.1016/j.cbpa.2014.11.014


  • eng