Issues

Editor's choice: Lactate is a metabolic fuel but it also stimulates breathing in vertebrates; in fish, this reflex is mediated by gill neuroepithelial cells, which act as lactate sensors.

Summary: Slowing of muscle contraction kinetics during development underlies the shift in the optimal frequency for maximal power output during jet propulsion swimming in cuttlefish.

Highlighted Article: Nocturnal to diurnal transitions in hawkmoths are accompanied by reduced separation between short- and long-wavelength sensitivity peaks which may be caused by parallel amino acid substitutions in visual opsins.

Highlighted Article: Mediterranean songbirds have limited cooling efficiencies and heat tolerance limits. This makes them sensitive to climate warming, particularly so under future climate change scenarios.

Summary: The speed with which triggerfish detect patterned stimuli cannot be explained by a single image statistic. The relationship between pattern statistics and animal behaviour is complex, and is likely to be distance dependent.

Summary: Behavioural phase transition in the Central American locust differs from that in the desert locust, suggesting that the expression and mechanisms of density-dependent behavioural plasticity in locusts may not be phylogenetically constrained.

Summary: There is a muscle-level trade-off between speed and endurance across replicated lines of mice experimentally selected for high levels of voluntary wheel running. However, this trade-off does not appear to underpin a previously reported organismal-level trade-off.

Highlighted Article: Despite discrete changes in kinematic magnitude and coordination, the pattern of axial red muscle and pectoral fin adductor activity remains similar across the aquatic–terrestrial transition in Polypterus senegalus.

Summary: The trajectories of electric fish change as they learn to find food. Initial random sharp turns transition to smooth trajectories, but remain unpredictable and not simple direct paths to food.

Summary: Thyroid hormones cause a significant increase in programmed cell death in post-ingression but not pre-ingression sea urchin larvae, indicating differential regulation of larval development by thyroid hormones via programmed cell death.

Summary: Challenging the adaptive immune system increases resting body temperature as part of an adequate immune response at the cost of elevated oxidative stress.