Summary: We review the metabolic, morphological and physiological features unique to embryonic and larval fishes that are necessary to cope with an amino acid-fuelled metabolism and lack of a functional gill.
Studying emotion in invertebrates: what has been done, what can be measured and what they can provide
Summary: Recent work has adapted methods for assessing emotions in humans and other animals, to invertebrates, with intriguing results. This Review interprets and discusses their utility with respect to the evolution and neurobiology of emotion.
Waiting for the Sun: the circannual programme of reindeer is delayed by the recurrence of rhythmical melatonin secretion after the arctic night
Summary: Exposure to constant light or constant darkness accelerates the onset of spring physiology in overwintering reindeer; this has implications for current models of circannual time-keeping in mammals.
Humeral loads during swimming and walking in turtles: implications for morphological change during aquatic reinvasions
Summary: Turtle humeri experience reduced torsional loads during swimming compared with terrestrial walking. Such reductions may have facilitated the transition from tubular to flattened limb bones in secondarily aquatic tetrapods.
METHODS & TECHNIQUES
Bringing the analysis of animal orientation data full circle: model-based approaches with maximum likelihood
Summary: A new statistical package developed in R for the maximum likelihood analysis of animal orientation data. Both simulated and empirical examples are provided for demonstration.
Re-oxygenation after anoxia induces brain cell death and memory loss in the anoxia-tolerant crucian carp
Highlighted Article: Anoxia-tolerant crucian carp sustain brain cell death during early re-oxygenation, as well as impaired memory, although damage is transient and does not diminish learning ability.
Summary: Functional trade-offs of the hyobranchial apparatus result in lower tongue-projection distance, velocity, acceleration and power in semi-aquatic and aquatic salamandrids compared with terrestrial specialists.
Beneficial effects of a heat wave: higher growth and immune components driven by a higher food intake
Summary: Damselfly larvae benefit from a heat wave by increasing growth rate and immune components, which can be attributed to an increase in food intake.
Metabolic costs imposed by hydrostatic pressure constrain bathymetric range in the lithodid crab Lithodes maja
Highlighted Article: Hyperbaric limitation of depth range suggests the incorporation of hydrostatic pressure into a complex model of environmental tolerance, where energy limitation constrains biogeographic range, and into the metabolic framework for ecology and evolution.
Summary: Male mosquitoes possess at least eight groups of auditory neurons distinct in frequency tuning. They gradually amplify receptor potentials in a non-spiking mode. Individual frequencies range from 85 to 470 Hz.
Summary: Haemoglobin–O2 binding properties of African mole rats reveal low specific CO2 sensitivities compared with humans that predictably safeguard O2 uptake and transport under hypoxic and hypercapnic conditions.
Summary: Placement of unrelated tadpoles on adult poison frogs triggers a cascade of parental behaviours involving tadpole transport and spatial memory use in both sexes, despite the asymmetric parental sex roles.
Editors' Choice: Fights between parasitoid females require little energy, but drilling through seeds to access hosts is expensive. Females avoid metabolic costs by reusing holes drilled by rivals (superparasitism).
Summary: The function of dorsal fins varies among shark species, and these fins can act in either a stabilizing or thrust-generating role.
Summary: Elevated temperature (>22°C) reduces growth rate and induces endocrine and cellular stress responses of brook trout. Daily temperature oscillation around a mean temperature of 21°C decreases growth and increases heat shock proteins.
Summary: Alkaline phosphatase activity and immunochemistry reveal that oyster germline cells are located in the gonad duct outer edge during the resting period and proliferate very early during the next sexual cycle.
Summary: Freshwater mayfly nymphs regulate salt and water balance using the alimentary canal, Malpighian tubules and tracheal gills, and data provide the first direct evidence that the tracheal gills are ion transport organs.
Highlighted Article: Investigation of the molecular mechanism of an ancient physiological behaviour in sponges in which engulfed quartz particles are fibrogenic and the process is cytokine mediated as in human fibrosis.
Natural epigenetic variation within and among six subspecies of the house sparrow, Passer domesticus
Summary: Genome-wide DNA methylation variation in subspecies of house sparrow is largely independent of subspecies designation and does not follow differences in habitat, but is associated with several other biological phenomena such as morphology, sex and commensalism.
Plausible link between circa‘bi’dian activity rhythms and circadian clock systems in the large black chafer Holotrichia parallela
Summary: The large black chafer Holotrichia parallela has an endogenous circa‘bi'dian rhythm, which is seemingly produced by the circadian clock system. The 2-day periodicity appears in both the laboratory and the field.
Mitochondrial capacity, oxidative damage and hypoxia gene expression are associated with age-related division of labor in honey bee (Apis mellifera L.) workers
Summary: Changes in mitochondrial activity and hypoxia gene expression in the head, thorax and abdomen of honey bee workers are associated with the nurse bee to forager transition.
Function of the hypobranchial muscles and hyoidiomandibular ligament during suction capture and bite processing in white-spotted bamboo sharks, Chiloscyllium plagiosum
Summary: Hypobranchial muscles of bamboo sharks allow for storage and release of elastic strain energy during suction feeding, which is facilitated by a four-bar linkage that links jaw and hyoid depression.
Variation in developmental trajectories of physiological and somatic traits in a common songbird approaching fledging
Summary: Developmental trajectory just prior to fledging in songbirds may be hardwired across natural and experimentally manipulated environmental conditions, but shows oxidative stress cost.
Sex hormones and the development of sexual size dimorphism: 5α-dihydrotestosterone inhibits growth in a female-larger lizard (Sceloporus undulatus)
Summary: Dihydrotestosterone mimics the effects of testosterone on growth and coloration in a female-larger lizard, and both sexes share downstream regulatory mechanisms required for growth inhibition and enhanced coloration in response to androgens.