Physiological Mechanisms of Acute Upper Thermal Tolerance in Fish

• This review is focused on the questions of why fish exhibit heat failure at thermal extremes and which physiological mechanisms determine the acute upper thermal tolerance. We propose that rapid direct thermal impacts on fish act through three fundamental molecular mechanisms reaction rates, protein structure, and membrane fluidity. During acute warming, these molecular effects then lead to loss of equilibrium and death through various cellular, organ, and physiological pathways. These pathways include mitochondrial dysfunction, oxygen limitation, and impacted excitability of excitable cells and eventually lead to neural and/or muscular failure. The pathways may also lead to loss of homeostasis and subsequent heat failure. There is strong evidence in some species for oxygen limitation in these processes and strong evidence against it in other species and contexts. The limiting mechanisms during acute warming therefore appear to differ between species, life stages, and recent thermal history. We conclude that a single mechanism underpinning the acute upper thermal tolerance across species and contexts will not be found. Therefore, we propose future avenues of research that can elucidate major patterns of physiological thermal limitations in fish

Ämnesord

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

Nyckelord

climate change

fish physiology

temperature

thermal biology

temperature-dependent biogeography

climate-change

oxygen limitation

common killifish

aerobic scope

homeoviscous adaptation

intraspecific

variation

growth-performance

heat

marine

Physiology

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)