Issues

Summary: This Commentary argues that the concept of the critical oxygen tension in water-breathers is fundamentally flawed for many reasons, and it presents the case for more useful alternatives.

Summary: The wide diversity of biological puncture systems, from snake fangs to jellyfish stings to cactus spines, is united by common physical parameters that determine puncture success, such as stress, energy, speed and material properties.

Summary: Tropical snails from thermally variable intertidal habitats exhibit substantial heat tolerance acclimation, contradicting the widely held expectations about tropical species lacking plasticity and basal heat tolerance constraining plasticity.

Summary: Intracellular load bearing by titin is functionally important in frog muscle but not in mouse muscle, which may be due to the more highly developed extracellular matrix in mouse.

Summary: Re-creation of the results of a well-cited study on honeybee magnetoreception using a random number generator demonstrates that the conclusions of the original paper were due to incorrect data analyses.

Summary: Droneflies innately prefer to land on yellow colours irrespective of UV reflection characteristics and can learn other colours, but refuse dark ones; the proboscis reflex is triggered only by yellow UV-absorbing colours.

Summary: Movements of the axial skeleton and shoulder girdle combine to increase forelimb stride length in high-walking alligators.

Summary: Reminiscent of field observations on Balanus balanoides by D. Crisp, F.R.S. in 1961, Amphibalanus amphitrite cyprids behave dose-dependently to the presence of their settlement-inducing protein complex in laboratory conditions.

Editors' Choice: Haemoglobin-less Antarctic icefish express a membrane-bound carbonic anhydrase that is plasma accessible and catalyses CO₂ excretion at the gills, to compensate for the loss of red blood cells with the enzyme.

Highlighted Article: High-resolution imaging of antennae reveals distinct patterns of sampling with non-redundant roles in odor tracking.

Highlighted Article: Moths maneuvering in the wake of flowers display simplified flower tracking dynamics. In the flower wake, the leading edge vortex does not burst and extends continuously across the wings and thorax.

Highlighted Article: Foraging common swifts spend the majority of their time gliding while making use of environmental energy such as thermals and gusts which, on average, completely cover the cost of flight.

Highlighted Article: Skin bacteria and skin odour profiles are clearly different between primate species, and mosquitoes with different host preferences respond differentially to these odours.

Summary: Opsin expression in adult specimens of three reef fish species belonging to two ecologically distinct families show different adaptive mechanisms to changes in available environmental light.

Summary: A systemic age­-dependent change in sphingolipid homeostasis in Drosophila methyltransferase 2 mutants that correlates with an age­-dependent decline of immune function.

Summary: The communication system of sand gobies is adapted to enhance sound transmission and reception in Atlantic shallow-water environments, supporting the acoustic adaptive hypothesis.

Summary: Biofeedback based on real-time inverse dynamics reveals that ankle power generation during walking influences workload placed on more proximal leg muscles, trailing leg mechanical output and step length.

Summary: A simple stability-based modeling approach can explain why walking insects use different leg coordination patterns in a speed-dependent way.

Summary: In savannah monitors, all dorsal ribs, both true and floating, contribute equally to ventilation, in contrast to green iguanas, where ventilation is dominated by the true ribs.

Summary: Manipulation of hematocrit in yellow-rumped warblers provides experimental evidence that the relationship between hematocrit and exercise performance is dependent on altitude.

Summary: Embryos are capable of metabolizing maternally derived yolk corticosterone to minimize exposure during development and to avoid deleterious effects on phenotype and survival.

Highlighted Article: Hyperoxia increases maximum oxygen uptake and metabolic scope in intertidal fish facing acutely high temperatures but does not increase upper thermal tolerance limits.

Summary: In jumping kangaroo rats, the ankle joint is responsible for the highest work output; however, a substantial proportion of this work is being transferred over the biarticular ankle extensors.

Summary: Overall step length variations, but not the organization of fluctuations, may predict changes in energy cost during walking.

Summary: High levels of red carotenoids (i.e. canthaxanthin) in the diet paradoxically lead to paler red coloration, which raises questions about potential constraints in the evolution of red carotenoid-based sexual signals.