chapter  2
Chapter 2Cardiovascular System
Pages 48

The cardiovascular system plays a critically important role in Œshes, as it does in all vertebrates: it  transportsoxygen,carbondioxide,metabolicsubstratesandwastes,hormones,andvarious immunefactorsthroughoutthebody.Assuch,itisoneofthemoststudiedorgansystemsinŒshes andthoughttobekeytounderstandingtheevolutionofthisvertebrategroup.Thecardiovascular systemalsodetermines,inpart,theecologicalnichethatcanbeoccupiedbymanyŒshspeciesand how they will/might be impacted by future abiotic and biotic changes. For example, over the past decade,ithasbeenrecognizedthatmetabolicscope(thedifferencebetweenrestingandmaximum metabolicrate)isakeydeterminantofŒshthermaltoleranceandthatthisparameterislargely determinedbythecapacityoftheŒshtodeliverenoughoxygentothetissuestomeettherising metabolicdemandastemperatureincreases(WangandOvergaard,2007;Farrell,2009;Pörtner et al., 2010; Gamperl, 2011).