Data from: Individual variation in whole-animal hypoxia tolerance is associated with cardiac hypoxia tolerance in a marine teleost

Hypoxia is a pervasive problem in coastal environments and is predicted to
have enduring impacts on aquatic ecosystems. Intraspecific variation in
hypoxia tolerance is well documented in fish; however, the factors
underlying this variation remain unknown. Here, we investigate the role of
the heart in individual hypoxia tolerance of the European sea bass
(Dicentrarchus labrax). We found individual whole-animal hypoxia tolerance
is a stable trait in sea bass for more than 18 months (duration of study).
We next examined in vitro cardiac performance and found myocardial muscle
from hypoxia-tolerant individuals generated greater force, with higher
rates of contraction and relaxation, than hypoxic-sensitive individuals
during hypoxic exposure. Thus, whole-animal hypoxia tolerance is
associated with cardiac hypoxia tolerance. As the occurrence of aquatic
hypoxia is expected to increase in marine ecosystems, our experimental
data suggest that cardiac performance may influence fish survival and
distribution.