Data from: Aerobic scope predicts dominance during early life in a tropical damselfish

A range of physiological traits are linked with aggression and dominance
within social hierarchies, but the role of individual aerobic capacity in
facilitating aggression has seldom been studied. Further, links previously
observed between an individual's metabolic rate and aggression level
may be context dependent and modulated by factors such as social stress
and competitor familiarity. We examined these issues in juvenile Ambon
damselfish, Pomacentrus amboinensis, which display intraspecific
competition for territories during settlement on coral reefs. Individuals
were measured for routine metabolic rate, aerobic scope, and anaerobic
capacity using intermittent-flow respirometry before dyadic dominance
contests. Post-contest, fish were measured for metabolic rate in isolation
and while interacting with their previous competitor or a stranger in
adjacent transparent respirometers. In arena contests, aerobic scope was
correlated with aggression and dominance, while routine metabolic rate and
anaerobic capacity were not related to dominance. Post-contest,
subordinates showed a rise in metabolic rate and decrease in available
aerobic scope, presumably due to social stress. Dominants increased
metabolic rate in the presence of a previous competitor, possibly due to
the stresses of hierarchy maintenance. Metabolic rate during aggressive
interactions did not approach that measured during exhaustive exercise,
suggesting individuals do not fully utilise their aerobic scope during
aggression. A greater aerobic scope may, however, allow faster
post-contest recovery. These results demonstrate a link between aerobic
scope and dominance during intraspecific competition for territory.
Selection on aerobic scope could therefore follow, either indirectly
through correlations with other traits influencing resource-holding
potential, or directly if aerobic scope carries benefits important for
territory acquisition or holding, such as an enhanced capacity to cope
with socially-induced stress.