Issues

Summary: Natural selection optimizes the way organisms spend their limiting resources on growth, reproduction and survival. We tie this process to learning performance in a snail model of neuronal ageing.

Summary: We describe a micro-ophthalmoscope that takes advantage of autofluorescent properties of invertebrate photoreceptors and allows for in vivo testing of refractive errors in small arthropod eyes.

Summary: Morphotype transformation in adult Macrobrachium rosenbergii males from orange to blue claw on augmentation of insulin-like androgenic gland hormone.

Summary: The regulation and molecular evolution of pigmentation in crustaceans is more complex than initially thought, with multiple lineage-specific duplications and functional redundancy in shrimp pigmentation genes.

Summary: Characterization of the Chilean blue whale vocal repertoire and a modified method of using DTAG accelerometers to identify calling blue whales.

Summary: Honeybee workers tend larvae around the clock; capped brood that is not fed, but not brood pheromones, attracts similar around-the-clock tending by individually isolated ‘nurse’ bees.

Summary: During a simple landing task, the compliance of elastic structures and muscle activity modulate energy absorption and dissipation via active lengthening of the triceps surae fascicles.

Highlighted Article: Variation in behavioural responses of humpback whales limits the effectiveness of a ramp-up procedure used to mitigate physiological effects of naval sonar on marine animals.

Summary: The prevailing light environment and circadian clock do not control circannual timing of reproductive phenotypes in spotted munia, suggesting independent circadian and circannual rhythm generation in seasonally breeding species.

Summary: Investigation of an unanticipated step on uneven ground reveals two distinct adaptive strategies: an ankle-based strategy when stepping with the forefoot, and a hip-based strategy when stepping with the rearfoot.

Summary: Active muscles from mice with a small titin deletion exhibit large deficits in net negative work, suggesting that titin contributes to energy storage and dissipation during stretch–shortening cycles.

Highlighted Article: When exposed to progressive hypoxia, bar-headed geese (biannual high-altitude migrators) increase ventilation and heart rate, whereas Andean geese (lifelong high-altitude residents) increase lung oxygen extraction and cardiac stroke volume.

Summary: Food supplementation could have a negative impact on breeding performance of wild urban great tits.

Summary: Having high numbers of midgut symbionts may bring costs to a host organism, which is a crucial finding for understanding the evolution of host–symbiont interactions.

Highlighted Article: Gaze-stabilizing optokinetic reflexes in Xenopus laevis tadpoles are systematically influenced by the parameters of the visual scene, likely because of properties of retinal motion processing.

Summary: Transparency in shrimp is reversibly disrupted after exposure to physiological or environmental stressors; the increase in opacity is associated with a corresponding increase in hemolymph perfusion to the abdominal musculature.

Summary: Myofilament contractility of turtle ventricle is more sensitive to physiological levels of acidosis than to increased inorganic phosphate. The myofilament calcium sensitivities of ventricles from turtles and other ectotherms are similar.

Summary: Differently shaped fish species use varying combinations of body–caudal fin and pectoral fin propulsion at different speeds. Gait is characterized as a trajectory through propulsive parameter space for analysis and comparison.

Summary: A novel mechanism is presented by which human ankle muscles use their elastic tendons to contribute mechanical work and produce acceleration during walking gait.

Summary: The scanning ion-selective electrode technique reveals that cold tolerance in Drosophila is linked to the ability to maintain ion balance through adaptive changes in epithelial K⁺ transport.

Summary: Turtles share auditory brainstem connectivity with other reptiles, as well as birds, and encode interaural time differences in the nucleus laminaris.

Summary: Tests on the effects of experimentally increased foraging effort on a suite of physiological metrics in a small passerine provide evidence for physiological adjustments and cost of high workload associated with foraging.

Highlighted Article: Variation in thermal experience and behavior contributes to inter-individual physiological variation within intertidal mussel beds, providing valuable insight into physiological plasticity and variable costs of defending against environmental stress.

Summary: Biologging of mussels in the rocky intertidal zone reveals substantial temperature differences over the scale of centimeters, while environmental conditions and mussel origin underlie variation in shell gaping behavior.