Locomotion is thermally sensitive in ectotherms and therefore it is typically expressed differently among thermally heterogenous environments.Locomotion is a complex function,and whereas physiological and behavioral t...Locomotion is thermally sensitive in ectotherms and therefore it is typically expressed differently among thermally heterogenous environments.Locomotion is a complex function,and whereas physiological and behavioral traits that infuence locomotor performance may respond to thermal variation throughout life,other contributing traits,like body shape,may have more restricted responses.How morphology affects locomotorperformance under variable temperature conditions is unknown.Here,we investigated 3 genetically distinct strains of zebrafsh,Danio rerio(AB,WIK,and Tu)with a shared multi-generational history at 28℃.After rearing fsh at 28℃,we measured prolonged swimming speed(Ucrit)at each of 6 temperatures(between 16℃ and 34℃).Speed was strongly positively correlated among temperatures,resulting in most amongindividual variation being temperature-independent(i.e.,fsh were relatively fast or slow across all temperatures).However,we also detectedsignifcant variation along 2 axes refecting temperature-dependent variation.Although strains differed in mean swimming performance,withinstrain(among-individual)patterns of speed variation were markedly consistent.Body shape and size explained signifcant variation amongindividuals in both temperature-independent and temperature-dependent axes of swimming speed variation.Notably,morphological traits thatwere most strongly associated with temperature-independent performance variation(i.e.,faster-slower)differed from those associated withtemperature-dependent(i.e.,hotter-colder)variation.Further,there were signifcant differences among strains in both the direction and strengthof association for specifc morphological traits.Our results suggest that thermally heterogenous environments could have complex effects onthe evolution of traits that contribute to whole organism performance traits.展开更多
基金funded by the Australian Research Council(DP180101801 awarded to K.M.)and The University of Queensland.
文摘Locomotion is thermally sensitive in ectotherms and therefore it is typically expressed differently among thermally heterogenous environments.Locomotion is a complex function,and whereas physiological and behavioral traits that infuence locomotor performance may respond to thermal variation throughout life,other contributing traits,like body shape,may have more restricted responses.How morphology affects locomotorperformance under variable temperature conditions is unknown.Here,we investigated 3 genetically distinct strains of zebrafsh,Danio rerio(AB,WIK,and Tu)with a shared multi-generational history at 28℃.After rearing fsh at 28℃,we measured prolonged swimming speed(Ucrit)at each of 6 temperatures(between 16℃ and 34℃).Speed was strongly positively correlated among temperatures,resulting in most amongindividual variation being temperature-independent(i.e.,fsh were relatively fast or slow across all temperatures).However,we also detectedsignifcant variation along 2 axes refecting temperature-dependent variation.Although strains differed in mean swimming performance,withinstrain(among-individual)patterns of speed variation were markedly consistent.Body shape and size explained signifcant variation amongindividuals in both temperature-independent and temperature-dependent axes of swimming speed variation.Notably,morphological traits thatwere most strongly associated with temperature-independent performance variation(i.e.,faster-slower)differed from those associated withtemperature-dependent(i.e.,hotter-colder)variation.Further,there were signifcant differences among strains in both the direction and strengthof association for specifc morphological traits.Our results suggest that thermally heterogenous environments could have complex effects onthe evolution of traits that contribute to whole organism performance traits.
