Issues

Summary: Magnetic orientation responses in animals are often weak and difficult to elicit experimentally. A possible explanation is that the magnetic compass is ‘noisy’ and cannot acquire precise magnetic information over short time periods.

Summary: The first experimental evidence of absolute worker sterility in a social insect species. Australian stingless bee workers under a manipulated social environment and diet are irreversibly sterile.

Highlighted Article: Annual killifish embryos survive over a year without water. Dormant and actively developing embryos exhibit opposite metabolic responses to dehydration. These responses may contribute to phenotypic variation associated with developmental bet hedging.

Highlighted Article: Nectar-feeding bats have very high daily energy demands. The bat Leptonycteris yerbabuenae discriminates very small sugar concentration differences, which helps it to avoid physiological constraints.

Highlighted Article: Long dives in Cuvier's beaked whales are not followed by prolonged recovery periods, suggesting that diving metabolism is reduced and/or undescribed mechanisms are used to process products of anaerobic metabolism.

Summary: A new method for plotting joint poses, inspired by a 16th century map projection, allows coordinate-system-independent measurements of joint mobility and enables accurate comparative studies of joint function.

Summary: A two-stage brood size manipulation experiment in Cyanistes caeruleus, with application of small-angle X-ray scattering and electron microscopy, revealed that structurally coloured feathers are more sensitive to conditions during feather growth than during the first days after hatching.

Summary: Several morphological modifications are likely to contribute to the stiffness of the novel walking appendages in the sea-robin and therefore their ability to facilitate underwater locomotion.

Summary: Males of the strepsipteran Stylops ovinae develop significantly higher forces on smooth than hairy surfaces; these forces are generated by adhesion and not by mechanical interlocking with host hairs.

Summary: A mutation in the serotonin neurotransmitter pathway that lowers basal stress levels but increases the amplitude of stress response can spread in cavefish populations living in singular environments.

Summary: Presentation and evaluation of ¹³C-labelled sodium bicarbonate (NaBi) combined with particle image velocimetry (PIV) for estimation of flight energetics in birds over a wide range of speeds.

Highlighted Article: The cytosolic malate dehydrogenase enzyme of the honeybee has three allozymes that show parallel temperature clines on four continents, reflecting the adaptive advantage/disadvantage of each allele at different temperatures.

Summary: Fluidic modelling and theoretical analysis of the honey bee feeding mechanism reveals an adaptation strategy in which bees respond to variation in nectar properties by regulating dipping frequency.

Summary: The energetic cost of epithelial ion transport in larval zebrafish is estimated to be low based on relatively constant in vivo O₂ flux across cutaneous ionocytes, despite widely varying rates of Na⁺ uptake.

Summary: Drosophila strains differ in their response to exercise stimulation, which is controlled at least in part by genetic variation and sex.

Summary: Bactrocera dorsalis can learn to discriminate three sugars – sucrose, fructose and glucose – through both pre- and post-ingestive signals, which might be a strategy for flies to assess the quality of the food.

Summary: A species contrast in patterns of noradrenaline levels reveals that different brain areas are responsible for the encoding of social signals versus preferences for those signals.

Summary: Incorporating appropriate fiber properties and muscle architecture is necessary to evaluate the contribution of individual muscles to combined plantarflexor force-velocity properties.

Editor's choice: Channel catfish use their dorsal body muscles to stabilize the head during suction feeding, while the ventral body muscles power mouth expansion.

Summary: Cortisol increases during exposure to seawater and exogenous cortisol upregulates gill NKA, NKCC and H⁺-ATPase and plasma glucose in sturgeon; thus, cortisol is a key osmoregulatory and glucocorticoid hormone in chondrosteans.