Issues

Summary: Studies of the evolution of aerobic capacity and the O₂ transport pathway can provide appreciable insight into the systems-level mechanisms underlying the evolution of complex performance traits.

Summary: Contraction of the python heart is initiated by pacemaker cells in the region between the left leaflet of sinoatrial valve and the posterior horn of the sinus venosus.

Summary: Pollen foragers were prone to recruiting bees with a tendency to collect pollen, whereas nectar foragers more frequently recruited bees that preferred sucrose solutions.

Summary: Adult-born cells in the zebrafish brain respond to brief visual stimuli, indicating that they have the ability to contribute to the regulation of social behavior.

Summary: The interaction between developmental and adult acclimation promotes heat survival in Drosophila melanogaster under specific conditions. Further, heat tolerance and heat stress recovery appear partly decoupled processes.

Summary: Perturbation of the endocannabinoid system in the first 24 h of development alters motor neuron development and locomotion in zebrafish.

Editor's Choice: A functional study on the role of the mitochondrial alternative oxidase (AOX) in an animal species indicates that AOX increases the sulphide tolerance of the marine chordate Ciona intestinalis.

Summary: Before becoming foragers, Melophorus bagoti ants took 3–7 learning walks around their nest. They increased the duration and area explored over successive walks, stopping occasionally to scan the environment.

Summary: Analysis of the siphon withdrawal reflex in Aplysia provides evidence for the hypothesis that sleep preferentially benefits learning that is more complex than conditioning of a simple reflex.

Summary: Fruit flies spend more time searching for food near attractive odors when the time since their last visit to a similar odor source is longer, which increases efficiency, as does stochasticity in the decision-making process.

Summary: The mechanical behaviour of the Achilles tendon explains apparent efficiency (the proportion of metabolic power that goes into useful mechanical power at the whole-body level) behaviour in bouncing gaits.

Summary: Flower shape preference tests show wild bees prefer the shape of Australian insect-pollinated flowers over bird-pollinated flowers, providing a valuable framework for further behavioural testing of non-eusocial bees.

Summary: Femoral bone blood flow, measured using fluorescent microspheres, is approximately two times higher in laying hens than in non-laying hens and roosters. Blood flow values were related to foramen sizes.

Summary: Electric images generated by species- and sex-specific electric organ discharges also encode information regarding relative position, which allows an individual fish to find a mate among sympatric species in muddy waters.

Highlighted Article: Echolocating porpoises can resolve targets from distractors when echoes arrive well below their auditory integration time, suggesting a short clutter interference zone where discrimination is aided by a directional biosonar.

Summary: Brook trout have a reduced ability to acclimate to temperatures ≥20°C, evidenced by changes in mRNA abundance, standard metabolic rate and recovery from exercise stress, with implications for survival under predicted climate change scenarios.

Summary: Ants with only right-eye vision can learn routes guided by a visual cue to the left: they turn leftwards, see the cue, then rightwards by the appropriate memorised angle.

Highlighted Article: Humans have dramatically reduced their ‘pelvic step’ – the ability of pelvic rotation to increase stride length – throughout hominin evolution.