Table of Contents
INSIDE JEB
COMMENTARIES
- Ammonia excretion in aquatic invertebrates: new insights and questions
Summary: This Commentary discusses the ammonia excretion strategies of invertebrates inhabiting a variety of different aquatic environments as well as the roles of excretory proteins in acid–base homeostasis.
- The utility of transcriptomics in fish conservation
Summary: Transcriptomic assessments, through functional analyses and the determination of negative impact thresholds, allow for a broad understanding of the mechanisms that regulate an organism's ability to respond to environmental change.
SHORT COMMUNICATIONS
- Map-like navigation from distances exceeding routine movements in the three-striped poison frog (Ameerega trivittata)
Summary: Three-striped poison frogs (Ameerega trivittata) can navigate home via a direct path from areas exceeding the range of their routine movements.
- Cognitive skills of common shrews (Sorex araneus) vary with seasonal changes in skull size and brain mass
Summary: Common shrews reduce their brain mass by 21% in winter, likely to cope with seasonal fluctuations in resources, and then regrow it by 17% the following spring, but spatial learning task experiments suggest they do so at the cost of a reduced cognitive ability in winter.
METHODS AND TECHNIQUES
- Determining forward speed from accelerometer jiggle in aquatic environments
Summary: Aquatic animal speed correlates exponentially with high-frequency accelerometer motion in underwater animal-attached devices, and the quantification of this motion can be used as a speed metric.
RESEARCH ARTICLES
- Myosin phosphorylation potentiates steady-state work output without altering contractile economy of mouse fast skeletal muscles
Summary: Myosin regulatory light chain phosphorylation potentiates dynamic contractile function of mouse fast skeletal muscles in vitro without decreasing contractile economy.
- Myosin phosphorylation improves contractile economy of mouse fast skeletal muscle during staircase potentiation
Summary: Myosin regulatory light chain phosphorylation increases the contractile economy (mechanical output:metabolic input) of wild-type mouse fast muscle compared with muscles devoid of the enzyme responsible for regulatory light chain phosphorylation.
- Lean, mean, lipolytic machines: lipid mobilization in rainbow trout during graded swimming
Summary: Rainbow trout behave like lipolytic machines that constantly mobilize lipid reserves in excess of energy requirements. High baseline lipolytic rates are not modulated by exercise, even when metabolic rate triples.
- Hormesis-like effect of mild larval crowding on thermotolerance in Drosophila flies
Summary: Mild crowding improves thermotolerance of Drosophila melanogaster larvae through potential hormetic mechanisms triggered by exposure to metabolic waste.
- Integration of celestial compass cues in the central complex of the locust brain
Highlighted Article: Polarization-sensitive neurons of the locust central complex show azimuth-dependent responses to unpolarized light spots, suggesting that direct sunlight supports the sky polarization compass in this brain area.
- Flexibility of feeding movements in pigs: effects of changes in food toughness and stiffness on the timing of jaw movements
Summary: In pigs, changes in food toughness impact chewing cycle duration and thus chewing frequency whereas changes in food stiffness alter phase duration within each cycle, with little effect on cycle duration.
- Movements of vastly different performance have similar underlying muscle physiology
Summary: Contractile properties and temperature effects are similar in tongue muscles from salamander species with different tongue-projection performance and mechanism (muscle power versus elastic recoil).
- Elucidating mechanisms for insect body size: partial support for the oxygen-dependent induction of moulting hypothesis
Summary: During a single larval instar, moths accumulated less and more mass before moulting under experimentally decreased and increased oxygen partial pressure, respectively, emphasising the role of oxygen in moult induction.
- Swim and fly: escape strategy in neustonic and planktonic copepods
Summary: New analysis supported by high-speed videos explains how some copepods can perform out-of-water escape jumps when aided by well-timed kicks when penetrating the surface.
- Protein synthesis is lowered by 4EBP1 and eIF2-α signaling while protein degradation may be maintained in fasting, hypoxic Amazonian cichlids Astronotus ocellatus
Summary: Hypoxia causes a decrease in metabolic rate, which is supported in part by a decrease in protein synthesis, and regulated by cell signaling pathways.
- Taking a goal-centred dynamic snapshot as a possibility for local homing in initially naïve bumblebees
Summary: Characteristics of initial outbound flights of bumblebees lead to a hypothesis how bumblebees use information gained in the close vicinity of their inconspicuous nest hole to return to their home location.
- Metabolome dynamics of diapause in the butterfly Pieris napi: distinguishing maintenance, termination and post-diapause phases
Highlighted Article: Diapause in a temperate butterfly is associated with a highly dynamic metabolome, and its termination, once initiated by cold, is associated with temperature-independent changes in profiles of several key metabolites.
- Too hard to swallow: a secret secondary defence of an aposematic insect
Highlighted Article: The hardness of aposematic weevils functions as an adaptive secondary defence against predator lizards, supporting Wallace's hypothesis of aposematism.
- Mechanisms for the functional differentiation of the propulsive and braking roles of the forelimbs and hindlimbs during quadrupedal walking in primates and felines
Summary: Theoretical models and empirical results reveal that functional differentiation of the limbs of quadrupeds in terms of net braking and propulsive roles is driven, in part, by the relative position of the limb point of contact relative to the center of mass.
- Odor source localization in complex visual environments by fruit flies
Summary: Fruit flies pinpoint the precise location of an odor source by integrating information derived from their visual and olfactory modalities, in both moving and still air.
- Multimodal sensorimotor system in unicellular zoospores of a fungus
Summary: The ability to respond to light and/or chemical gradients varies between Allomyces zoospores, a new model for sensory evolution; A. arbusculus behavior represents a multimodal, sensorimotor system in unicellular fungi.
- Evaluating the triplet hypothesis during rhythmic mastication in primates
Summary: The prevalence of the jaw elevator triplet motor pattern during mastication is established in five different primate species.
This issue
Other journals from The Company of Biologists
Editors’ choice – Accurate archerfish calculate fly height in an instant
Our most recent Editors’ choice is a pair of articles that examine rapid depth perception in hunting archerfish from Caroline P. Reinel and Stefan Schuster (I. The predictive C-starts, II. An analysis of potential cues). Archerfish have an impressive ability to predict where the prey that they topple from perches will land and now it turns out that they are able to calculate the height that a victim will fall in the first 100 ms of the descent.
Featured article – Dragonfly haemolymph looks more like ancestors’
Animals that live in the air have high levels of CO2 in their bodies, while aquatic species have lower CO2 levels, but what about the internal CO2 levels of animals that evolved in air but returned to the water for part of their lives? Philip Matthews and colleagues have discovered that the CO2 in the haemolymph of aquatic dragonfly nymphs is high, like that of air breathers, even though they live in water.
Conversation – Erika Eliason
“So much of science is about things going wrong, failing epically, and I think you have to be able to pick yourself up and figure out what went wrong.”
Erika Eliason is an Assistant Professor at University of California, Santa Barbara, USA, where she studies ecological and evolutionary physiology. She shares how a childhood spent discovering the natural world in the woods where she grew up ignited her love for science and fieldwork, why conferences should be more family-friendly and the importance of being prepared for the unexpected.
Commentary – Mechanisms underpinning the beneficial effects of fluctuating thermal regimes in insect cold tolerance
Exposure to low temperature often results in death or injury for insects. However, repeated brief warm pulses during periods of low-temperature stress have been shown to confer some protection. Kendra J. Greenlee and colleagues provide an overview of the critical elements that underpin this phenomenon.
Meet the team
Are you going to the 2018 APS Comparative Physiology meeting in October? This meeting is supported by JEB and our Reviews Editor Charlotte Rutledge will be there - stop by and say hello! Advance registration is open until 24 September 2018.
preLights – Are Robofish accepted as a guppy conspecific?
Rasmus Ern highlights a preprint in which Jens Krause and colleagues use a magnet-controlled, 3D-printed fish replica to study social responsiveness in guppies.