
Hyperoxia increases maximum oxygen consumption and aerobic scope of intertidal fish facing acutely high temperatures
Author(s) -
Tristan McArley,
Anthony J. R. Hickey,
Neill A. Herbert
Publication year - 2018
Publication title -
journal of experimental biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.367
H-Index - 185
eISSN - 1477-9145
pISSN - 0022-0949
DOI - 10.1242/jeb.189993
Subject(s) - hyperoxia , intertidal zone , oxygen , environmental science , ecology , critical thermal maximum , acclimatization , biology , atmospheric sciences , chemistry , geology , organic chemistry
Daytime low tides that lead to high temperature events in stranded rock pools often co-occur with algal mediated hyperoxia as a result of strong solar radiation. Recent evidence shows aerobic metabolic scope (MS) can be expanded under hyperoxia in fish but so far this possibility has not been examined in intertidal species despite being an ecologically relevant scenario. Furthermore, it is unknown whether hyperoxia increases the upper thermal tolerance limits of intertidal fish and, therefore the ability to withstand extreme high temperature events. Therefore we measured the metabolic response (mass specific rate of oxygen consumption [ṀO2]) to thermal ramping (21-29°C) and the upper thermal tolerance limit (UTL) of two intertidal triplefin fishes (Bellapiscis medius and Forsterygion lapillum) under hyperoxia and normoxia. Hyperoxia increased maximal oxygen consumption (ṀO2,max) and MS of each species at ambient temperature (21°C) but also after thermal ramping to elevated temperatures such as those observed in rock pools (29°C). While hyperoxia did not provide a biologically meaningful increase in upper thermal tolerance of either species (>31°C under all conditions) the observed expansion of MS at 29°C under hyperoxia could potentially benefit the aerobic performance, hence the growth and feeding potential etc., of intertidal fish at non-critical temperatures. That hyperoxia does not increase upper thermal tolerance in a meaningful way is cause for concern as climate change is expected to drive more extreme rock pool temperatures in the future and this could present a major challenge for these species.