Evidence for a southward autumn migration of nocturnal noctuid moths in central Europe [RESEARCH ARTICLE]
David Dreyer, Basil el Jundi, Dmitry Kishkinev, Carina Suchentrunk, Lena Campostrini, Barrie J. Frost, Thomas Zechmeister, and Eric J. Warrant Insect migrations are spectacular natural events and resemble a remarkable relocation of biomass between two locations in space. Unlike the well-known migrations of daytime flying butterflies, such as the painted lady (Vanessa cardui) or the monarch butterfly (Danaus plexippus), much less widely known are the migrations of nocturnal moths. These migrations – typically involving billions of moths from different taxa – have recently attracted considerable scientific atten...
Source: Journal of Experimental Biology - December 14, 2018 Category: Biology Authors: Dreyer, D., el Jundi, B., Kishkinev, D., Suchentrunk, C., Campostrini, L., Frost, B. J., Zechmeister, T., Warrant, E. J. Tags: Neuroethology RESEARCH ARTICLE Source Type: research

Intrepid rafting weevil larvae survive 6 days at sea [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - December 13, 2018 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Rafting on floating fruit is effective for oceanic dispersal of flightless weevils [RESEARCH ARTICLE]
This study provides the first empirical evidence that P. jitanasaius larvae can survive ‘rafting’ on ocean currents and that the eggs and larvae of these weevils have the highest probability of crossing the oceanic barrier. This ability may facilitate over-the-sea dispersal of these flightless insects and further shape their distribution and speciation pattern in the Western Pacific islands. (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - December 13, 2018 Category: Biology Authors: Yeh, H.-Y., Tseng, H.-Y., Lin, C.-P., Liao, C.-P., Hsu, J.-Y., Huang, W.-S. Tags: RESEARCH ARTICLE Source Type: research

Diapause-associated changes in the lipid and metabolite profiles of the Asian tiger mosquito, Aedes albopictus [RESEARCH ARTICLE]
Zachary A. Batz and Peter A. Armbruster Diapause is an alternative life-history strategy that allows organisms to enter developmental arrest in anticipation of unfavorable conditions. Diapause is widespread among insects and plays a key role in enhancing overwinter survival as well as defining the seasonal and geographic distributions of populations. Next-generation sequencing has greatly advanced our understanding of the transcriptional basis for this crucial adaptation but less is known about the regulation of embryonic diapause physiology at the metabolite level. Here, we characterized the lipid and metabolite profiles...
Source: Journal of Experimental Biology - December 13, 2018 Category: Biology Authors: Batz, Z. A., Armbruster, P. A. Tags: RESEARCH ARTICLE Source Type: research

Diet and ambient temperature interact to shape plasma fatty acid composition, basal metabolic rate and oxidative stress in great tits [RESEARCH ARTICLE]
Martin N. Andersson, Johan Nilsson, Jan-Ake Nilsson, and Caroline Isaksson Diet and ambient temperature affect animal physiology, survival and reproductive success. However, knowledge of how these environmental factors interact to shape physiological processes and life-history traits of birds and other animals is largely lacking. By exposing adult great tits (Parus major) to two contrasting diets (saturated or unsaturated fatty acids; SFAs and UFAs, respectively) and ambient temperatures (3°C versus 20°C) that the birds encounter in nature, we investigated the effects of these two factors on several physiological ...
Source: Journal of Experimental Biology - December 13, 2018 Category: Biology Authors: Andersson, M. N., Nilsson, J., Nilsson, J.-A., Isaksson, C. Tags: RESEARCH ARTICLE Source Type: research

Flung-back forelimbs help some lizards flip up [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - December 12, 2018 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Jet-paddling jellies: swimming performance in the Rhizostomeae jellyfish Catostylus mosaicus [RESEARCH ARTICLE]
Thomas R. Neil and Graham N. Askew Jellyfish are a successful and diverse class of animals that swim via jet propulsion, with swimming performance and propulsive efficiency being related to the animal's feeding ecology and body morphology. The Rhizostomeae jellyfish lack tentacles but possess four oral lobes and eight trailing arms at the centre of their bell, giving them a body morphology quite unlike that of other free-swimming medusae. The implications of this body morphology on the mechanisms by which thrust is produced are unknown. Here, we determined the wake structure and propulsive efficiency in the blue-blubber j...
Source: Journal of Experimental Biology - December 12, 2018 Category: Biology Authors: Neil, T. R., Askew, G. N. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

The role of parasitism in the energy management of a free-ranging bird [RESEARCH ARTICLE]
Olivia Hicks, Sarah J. Burthe, Francis Daunt, Mark Newell, Olivier Chastel, Charline Parenteau, and Jonathan A. Green Parasites often prompt sub-lethal costs to their hosts by eliciting immune responses. These costs can be hard to quantify but are crucial to our understanding of the host's ecology. Energy is a fundamental currency to quantify these costs, as energetic trade-offs often exist between key fitness-related processes. Daily energy expenditure (DEE) comprises of resting metabolic rate (RMR) and energy available for activity, which are linked via the energy management strategy of an organism. Parasitism may play ...
Source: Journal of Experimental Biology - December 12, 2018 Category: Biology Authors: Hicks, O., Burthe, S. J., Daunt, F., Newell, M., Chastel, O., Parenteau, C., Green, J. A. Tags: RESEARCH ARTICLE Source Type: research

Underlying mechanisms and ecological context of variation in exploratory behavior of the Argentine ant, Linepithema humile [RESEARCH ARTICLE]
Hannah Page, Andrew Sweeney, Anna Pilko, and Noa Pinter-Wollman Uncovering how and why animals explore their environment is fundamental for understanding population dynamics, the spread of invasive species, species interactions, etc. In social animals, individuals within a group can vary in their exploratory behavior, and the behavioral composition of the group can determine its collective success. Workers of the invasive Argentine ant (Linepithema humile) exhibit individual variation in exploratory behavior, which affects the colony's collective nest selection behavior. Here, we examine the mechanisms underlying this beh...
Source: Journal of Experimental Biology - December 12, 2018 Category: Biology Authors: Page, H., Sweeney, A., Pilko, A., Pinter-Wollman, N. Tags: RESEARCH ARTICLE Source Type: research

Temperature and dehydration effects on metabolism, water uptake and the partitioning between respiratory and cutaneous evaporative water loss in a terrestrial toad [RESEARCH ARTICLE]
Luis Miguel Senzano and Denis Vieira Andrade Terrestrial anurans often experience fluctuations in body temperature and hydration state, which are known to influence evaporative water loss through the skin (EWLSkin) and lungs (EWLResp). These effects arise from associated changes in skin permeability, metabolism and lung ventilation. Herein, we determined the rates of EWLSkin and EWLResp in the terrestrial toad Rhinella diptycha at different temperatures and hydration states. We measured oxygen uptake rates to verify whether alterations in the partitioning between EWLSkin and EWLResp were associated with metabolism-induced...
Source: Journal of Experimental Biology - December 12, 2018 Category: Biology Authors: Senzano, L. M., Andrade, D. V. Tags: RESEARCH ARTICLE Source Type: research

Scaling of claw sharpness: mechanical constraints reduce attachment performance in larger insects [RESEARCH ARTICLE]
Jonathan G. Pattrick, David Labonte, and Walter Federle Claws are the most widespread attachment devices in animals, but comparatively little is known about the mechanics of claw attachment. A key morphological parameter in determining attachment ability is claw sharpness; however, there is a conflict between sharpness and fracture resistance. Sharper claws can interlock on more surfaces but are more likely to break. Body size interacts with this conflict such that larger animals should have much blunter claws and consequently poorer attachment ability than smaller animals. This expected size-induced reduction in attachme...
Source: Journal of Experimental Biology - December 12, 2018 Category: Biology Authors: Pattrick, J. G., Labonte, D., Federle, W. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

Mechanical behavior of shark vertebral centra at biologically relevant strains [RESEARCH ARTICLE]
Danielle I. Ingle, Lisa J. Natanson, and Marianne E. Porter Cartilaginous shark skeletons experience axial deformation at the intervertebral joints, but also within the mineralized cartilaginous centrum, which can compress to between 3% and 8% of its original length in a free-swimming shark. Previous studies have focused on shark centra mechanical properties when loaded to failure; our goal was to determine properties when compressed to a biologically relevant strain. We selected vertebrae from six shark species and from the anterior and posterior regions of the vertebral column. Centra were X-radiographed to measure doub...
Source: Journal of Experimental Biology - December 12, 2018 Category: Biology Authors: Ingle, D. I., Natanson, L. J., Porter, M. E. Tags: RESEARCH ARTICLE Source Type: research

Interactions between corticosterone phenotype, environmental stressor pervasiveness and irruptive movement-related survival in the cane toad [RESEARCH ARTICLE]
Tim S. Jessop, Jonathan Webb, Tim Dempster, Benjamin Feit, and Mike Letnic Animals use irruptive movement to avoid exposure to stochastic and pervasive environmental stressors that impact fitness. Beneficial irruptive movements transfer individuals from high-stress areas (conferring low fitness) to alternative localities that may improve survival or reproduction. However, being stochastic, environmental stressors can limit an animal's preparatory capacity to enhance irruptive movement performance. Thus individuals must rely on pre-existing, or rapidly induced, physiological and behavioural responses. Rapid elevation of gl...
Source: Journal of Experimental Biology - December 12, 2018 Category: Biology Authors: Jessop, T. S., Webb, J., Dempster, T., Feit, B., Letnic, M. Tags: RESEARCH ARTICLE Source Type: research

Subspecies differences in thermal acclimation of mitochondrial function and the role of uncoupling proteins in killifish [RESEARCH ARTICLE]
Heather J. Bryant, Dillon J. Chung, and Patricia M. Schulte Thermal effects on mitochondrial efficiency and ATP production can influence whole-animal thermal tolerance and performance. Thus, organisms may have the capacity to alter mitochondrial processes through acclimation or adaptation to mitigate these effects. One possible mechanism is through the action of uncoupling proteins (UCPs), which can decrease the proton-motive force independent of the production of ATP. To test this hypothesis, we examined the mRNA expression patterns of UCP isoforms and characterized the effects of thermal acclimation and putative local t...
Source: Journal of Experimental Biology - December 12, 2018 Category: Biology Authors: Bryant, H. J., Chung, D. J., Schulte, P. M. Tags: RESEARCH ARTICLE Source Type: research

Forelimb position affects facultative bipedal locomotion in lizards [RESEARCH ARTICLE]
This study quantified the frequency of bipedalism when sprinting with versus without an obstacle at 0.8 m from the start of a sprint. Forelimb positions were quantified during bipedal running at the start of a sprint and when crossing an obstacle. Two species with contrasting body forms (and thus different BCoM) were studied (Sceloporus woodi and Aspidoscelis sexlineata) to assess potential variation due to body plan and obstacle-crossing behavior. No significant difference in frequency of bipedalism was observed in S. woodi with or without an obstacle. However, A. sexlineata primarily used a bipedal posture when spri...
Source: Journal of Experimental Biology - December 12, 2018 Category: Biology Authors: Kinsey, C. T., McBrayer, L. D. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

Unraveling inter-species differences in hagfish slime skein deployment [RESEARCH ARTICLE]
Mark A. Bernards Jr, Sarah Schorno, Evan McKenzie, Timothy M. Winegard, Isdin Oke, David Plachetzki, and Douglas S. Fudge Hagfishes defend themselves from fish predators by producing defensive slime consisting of mucous and thread components that interact synergistically with seawater to pose a suffocation risk to their attackers. Deployment of the slime occurs in a fraction of a second and involves hydration of mucous vesicles as well as unraveling of the coiled threads to their full length of ~150 mm. Previous work showed that unraveling of coiled threads (or ‘skeins’) in Atlantic hagfish requires vigor...
Source: Journal of Experimental Biology - December 12, 2018 Category: Biology Authors: Bernards, M. A., Schorno, S., McKenzie, E., Winegard, T. M., Oke, I., Plachetzki, D., Fudge, D. S. Tags: RESEARCH ARTICLE Source Type: research

Sauntering macaques: not walking but running [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - December 10, 2018 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Contraction speed and type influences rapid utilisation of available muscle force: neural and contractile mechanisms [RESEARCH ARTICLE]
This study investigated the influence of contraction speed and type on the human ability to rapidly increase torque and utilise the available maximum voluntary torque (MVT) as well as the neuromuscular mechanisms underpinning any effects. Fifteen young, healthy males completed explosive voluntary knee extensions in five conditions: isometric (ISO), and both concentric and eccentric at two constant accelerations of 500 deg s–2 (CONSLOW and ECCSLOW) and 2000 deg s–2 (CONFAST and ECCFAST). Explosive torque and quadriceps EMG were recorded every 25 ms up to 150 ms from their respective...
Source: Journal of Experimental Biology - December 10, 2018 Category: Biology Authors: Tillin, N. A., Pain, M. T. G., Folland, J. P. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

Food dissemination in ants: robustness of the trophallactic network against resource quality [SHORT COMMUNICATION]
Olivier Bles, Jean-Louis Deneubourg, and Stamatios C. Nicolis Insect societies are often composed of many individuals, achieving collective decisions that depend on environmental and colonial characteristics. For example, ants are able to focus their foraging effort on the most rewarding food source. While this phenomenon is well known, the link between the food source quality and the intranidal food dissemination networks and its dynamics has been neglected. Here, we analysed the global dynamics of food dissemination in Camponotus cruentatus workers, after feeding on a low (0.1 mol l–1) or on a high (1&nb...
Source: Journal of Experimental Biology - December 10, 2018 Category: Biology Authors: Bles, O., Deneubourg, J.-L., Nicolis, S. C. Tags: SHORT COMMUNICATION Source Type: research

Three-dimensional shape and velocity changes affect responses of a locust visual interneuron to approaching objects [RESEARCH ARTICLE]
Tarquin P. Stott, Erik G. N. Olson, Rachel H. Parkinson, and John R. Gray Adaptive collision avoidance behaviours require accurate detection of complex spatiotemporal properties of an object approaching in an animal's natural, three-dimensional environment. Within the locust, the lobula giant movement detector and its postsynaptic partner, the descending contralateral movement detector (DCMD), respond robustly to images that emulate an approaching two-dimensional object and exhibit firing rate modulation correlated with changes in object trajectory. It is not known how this pathway responds to visual expansion of a three-...
Source: Journal of Experimental Biology - December 10, 2018 Category: Biology Authors: Stott, T. P., Olson, E. G. N., Parkinson, R. H., Gray, J. R. Tags: Neuroethology RESEARCH ARTICLE Source Type: research

Ascending flight and decelerating vertical glides in Anna's hummingbirds [RESEARCH ARTICLE]
Victor Manuel Ortega-Jimenez and Robert Dudley Hummingbirds are observationally well known for their capacity to vertically ascend whilst hovering, but the underlying mechanics and possible energetic limits to ascent rates are unclear. Decelerations during vertical ascent to a fixed target may also be associated with specific visual responses to regulate the body's trajectory. Here, we studied climbing flight and subsequent deceleration in male Anna's hummingbirds (Calypte anna) over an approximately 2 m vertical distance. Birds reached vertical speeds and accelerations up to ~4 m s–1 and 10 m s&...
Source: Journal of Experimental Biology - December 10, 2018 Category: Biology Authors: Ortega-Jimenez, V. M., Dudley, R. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

Echo interval and not echo intensity drives bat flight behavior in structured corridors [RESEARCH ARTICLE]
Michaela Warnecke, Silvio Macias, Benjamin Falk, and Cynthia F. Moss To navigate in the natural environment, animals must adapt their locomotion in response to environmental stimuli. The echolocating bat relies on auditory processing of echo returns to represent its surroundings. Recent studies have shown that echo flow patterns influence bat navigation, but the acoustic basis for flight path selection remains unknown. To investigate this problem, we released bats in a flight corridor with walls constructed of adjacent individual wooden poles, which returned cascades of echoes to the flying bat. We manipulated the spacing...
Source: Journal of Experimental Biology - December 10, 2018 Category: Biology Authors: Warnecke, M., Macias, S., Falk, B., Moss, C. F. Tags: Neuroethology RESEARCH ARTICLE Source Type: research

High-frequency temperature variability mirrors fixed differences in thermal limits of the massive coral Porites lobata [RESEARCH ARTICLE]
Daniel J. Barshis, Charles Birkeland, Robert J. Toonen, Ruth D. Gates, and Jonathon H. Stillman Spatial heterogeneity in environmental characteristics can drive adaptive differentiation when contrasting environments exert divergent selection pressures. This environmental and genetic heterogeneity can substantially influence population and community resilience to disturbance events. Here, we investigated corals from the highly variable back-reef habitats of Ofu Island in American Samoa that thrive in thermal conditions known to elicit widespread bleaching and mortality elsewhere. To investigate the relative importance of a...
Source: Journal of Experimental Biology - December 10, 2018 Category: Biology Authors: Barshis, D. J., Birkeland, C., Toonen, R. J., Gates, R. D., Stillman, J. H. Tags: Ecophysiology: responses to environmental stressors and change RESEARCH ARTICLE Source Type: research

Global dynamics of bipedal macaques during grounded and aerial running [RESEARCH ARTICLE]
Reinhard Blickhan, Emanuel Andrada, Eishi Hirasaki, and Naomichi Ogihara Macaques trained to perform bipedally use grounded running, skipping and aerial running, but avoid walking. The preference for grounded running across a wide range of speeds is substantially different from the locomotion habits observed in humans, which may be the result of differences in leg compliance. In the present study, based on kinematic and dynamic observations of three individuals crossing an experimental track, we investigated global leg properties such as leg stiffness and viscous damping during grounded and aerial running. We found that, ...
Source: Journal of Experimental Biology - December 10, 2018 Category: Biology Authors: Blickhan, R., Andrada, E., Hirasaki, E., Ogihara, N. Tags: RESEARCH ARTICLE Source Type: research

Hunting in archerfish - an ecological perspective on a remarkable combination of skills [REVIEW]
Stefan Schuster Archerfish are well known for using jets of water to dislodge distant aerial prey from twigs or leaves. This Review gives a brief overview of a number of skills that the fish need to secure prey with their shooting technique. Archerfish are opportunistic hunters and, even in the wild, shoot at artificial objects to determine whether these are rewarding. They can detect non-moving targets and use efficient search strategies with characteristics of human visual search. Their learning of how to engage targets can be remarkably efficient and can show impressive degrees of generalization, including learning fro...
Source: Journal of Experimental Biology - December 10, 2018 Category: Biology Authors: Schuster, S. Tags: Neuroethology REVIEW Source Type: research

Do arthropods feel anxious during molts? [SHORT COMMUNICATION]
Julien Bacque-Cazenave, Marion Berthomieu, Daniel Cattaert, Pascal Fossat, and Jean Paul Delbecque The molting process of arthropods, chiefly controlled by ecdysteroids, is generally considered very stressful. Our previous investigations have shown that crayfish, after having experienced stressing situations, display anxiety-like behavior (ALB), characterized by aversion to light in a dark/light plus-maze (DLPM). In the present experiments, the spontaneous exploratory behavior of isolated crayfish was analyzed in a DLPM at different stages of their molt cycle. All tested animals displayed transitory aversion to light simil...
Source: Journal of Experimental Biology - December 10, 2018 Category: Biology Authors: Bacque-Cazenave, J., Berthomieu, M., Cattaert, D., Fossat, P., Delbecque, J. P. Tags: SHORT COMMUNICATION Source Type: research

Orienting to polarized light at night--matching lunar skylight to performance in a nocturnal beetle [RESEARCH ARTICLE]
James J. Foster, John D. Kirwan, Basil el Jundi, Jochen Smolka, Lana Khaldy, Emily Baird, Marcus J. Byrne, Dan-Eric Nilsson, Sönke Johnsen, and Marie Dacke For polarized light to inform behaviour, the typical range of degrees of polarization observable in the animal's natural environment must be above the threshold for detection and interpretation. Here we present the first investigation of the degree of linear polarization threshold for orientation behaviour in a nocturnal species, with specific reference to the range of degrees of polarization measured in the night sky. An effect of lunar phase on the degree of polariz...
Source: Journal of Experimental Biology - December 10, 2018 Category: Biology Authors: Foster, J. J., Kirwan, J. D., el Jundi, B., Smolka, J., Khaldy, L., Baird, E., Byrne, M. J., Nilsson, D.-E., Johnsen, S., Dacke, M. Tags: RESEARCH ARTICLE Source Type: research

Traction reinforcement in prehensile feet of harvestmen (Arachnida, Opiliones) [RESEARCH ARTICLE]
Jonas O. Wolff, Chantal Wiegmann, Christian S. Wirkner, Alexander Koehnsen, and Stanislav N. Gorb Prehensile and gripping organs are recurring structures in different organisms that enhance friction by the reinforcement and redirection of normal forces. The relationship between organ structure and biomechanical performance is poorly understood, despite a broad relevance for microhabitat choice, movement ecology and biomimetics. Here, we present the first study of the biomechanics of prehensile feet in long-legged harvestmen. These arachnids exhibit the strongest sub-division of legs among arthropods, permitting extreme hyp...
Source: Journal of Experimental Biology - December 10, 2018 Category: Biology Authors: Wolff, J. O., Wiegmann, C., Wirkner, C. S., Koehnsen, A., Gorb, S. N. Tags: RESEARCH ARTICLE Source Type: research

Nitrogen handling in the elasmobranch gut: a role for microbial urease [RESEARCH ARTICLE]
Chris M. Wood, Hon Jung Liew, Gudrun De Boeck, J. Lisa Hoogenboom, and W. Gary Anderson Ureotelic elasmobranchs require nitrogen for both protein growth and urea-based osmoregulation, and therefore are probably nitrogen-limited in nature. Mechanisms exist for retaining and/or scavenging nitrogen at gills, kidney, rectal gland, and gut, but as yet, the latter are not well characterized. Intestinal sac preparations of the Pacific spiny dogfish shark (Squalus acanthias suckleyi) incubated in vitro strongly reabsorbed urea from the lumen after feeding, but mucosal fluid ammonia concentrations increased with incubation time. Ph...
Source: Journal of Experimental Biology - December 10, 2018 Category: Biology Authors: Wood, C. M., Liew, H. J., De Boeck, G., Hoogenboom, J. L., Anderson, W. G. Tags: RESEARCH ARTICLE Source Type: research

Social stress increases plasma cortisol and reduces forebrain cell proliferation in subordinate male zebrafish (Danio rerio) [RESEARCH ARTICLE]
Jonathan Tea, Sarah L. Alderman, and Kathleen M. Gilmour Many animals, including zebrafish (Danio rerio), form social hierarchies through competition for limited resources. Socially subordinate fish may experience chronic stress, leading to prolonged elevation of the glucocorticoid stress hormone cortisol. Since elevated cortisol levels can impair neurogenesis, the present study tested the hypothesis that social stress suppresses cell proliferation in the telencephalon of subordinate zebrafish via a cortisol-mediated mechanism. Cell proliferation was assessed using incorporation of the thymidine analogue, 5-bromo-2'-deoxyu...
Source: Journal of Experimental Biology - December 10, 2018 Category: Biology Authors: Tea, J., Alderman, S. L., Gilmour, K. M. Tags: RESEARCH ARTICLE Source Type: research

Side-swimming plankton snail flaps shell like a fin [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - December 7, 2018 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Using a shell as a wing: pairing of dissimilar appendages in atlantiid heteropod swimming [SHORT COMMUNICATION]
Ferhat Karakas, Daniel D'Oliveira, Amy E. Maas, and David W. Murphy Atlantiid heteropods are zooplanktonic marine snails which have a calcium carbonate shell and single swimming fin. They actively swim to hunt prey and vertically migrate. Previous accounts of atlantiid heteropod swimming described these animals sculling with the swimming fin while the shell passively hung beneath the body. Here, we show, via high-speed stereophotogrammetric measurements of body, fin and shell kinematics, that the atlantiid heteropod Atlanta selvagensis actively flaps both the swimming fin and shell in a highly coordinated wing-like manner...
Source: Journal of Experimental Biology - December 7, 2018 Category: Biology Authors: Karakas, F., D'Oliveira, D., Maas, A. E., Murphy, D. W. Tags: SHORT COMMUNICATION Source Type: research

Porpoises have higher metabolic rates than thought to keep warm in cold water [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - December 6, 2018 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

High field metabolic rates of wild harbour porpoises [RESEARCH ARTICLE]
Laia Rojano-Donate, Birgitte I. McDonald, Danuta M. Wisniewska, Mark Johnson, Jonas Teilmann, Magnus Wahlberg, Jakob Hojer-Kristensen, and Peter T. Madsen Reliable estimates of field metabolic rates (FMRs) in wild animals are essential for quantifying their ecological roles, as well as for evaluating fitness consequences of anthropogenic disturbances. Yet, standard methods for measuring FMR are difficult to use on free-ranging cetaceans whose FMR may deviate substantially from scaling predictions using terrestrial mammals. Harbour porpoises (Phocoena phocoena) are among the smallest marine mammals, and yet they live in co...
Source: Journal of Experimental Biology - December 6, 2018 Category: Biology Authors: Rojano-Donate, L., McDonald, B. I., Wisniewska, D. M., Johnson, M., Teilmann, J., Wahlberg, M., Hojer-Kristensen, J., Madsen, P. T. Tags: RESEARCH ARTICLE Source Type: research

Distinct metabolic adjustments arise from acclimation to constant hypoxia and intermittent hypoxia in estuarine killifish (Fundulus heteroclitus) [RESEARCH ARTICLE]
We examined how killifish adjust O2 supply and demand during acute hypoxia, and how these responses are altered after prolonged acclimation to constant or intermittent patterns of hypoxia exposure. We acclimated killifish to normoxia (~20 kPa O2), constant hypoxia (2 kPa) or intermittent cycles of nocturnal hypoxia (12 h:12 h normoxia:hypoxia) for 28 days, and then compared whole-animal O2 consumption rates (MO2) and tissue metabolites during exposure to 12 h of hypoxia followed by reoxygenation in normoxia. Normoxia-acclimated fish experienced a pronounced 27% drop in MO2 during acu...
Source: Journal of Experimental Biology - December 5, 2018 Category: Biology Authors: Borowiec, B. G., McClelland, G. B., Rees, B. B., Scott, G. R. Tags: RESEARCH ARTICLE Source Type: research

An attempt to select non-genetic variation in resistance to starvation and reduced chill coma recovery time in Drosophila melanogaster [RESEARCH ARTICLE]
Bianca F. Menezes, Judit Salces-Ortiz, Heloïse Muller, Nelly Burlet, Sonia Martinez, Marie Fablet, and Cristina Vieira Phenotypic variance is attributed to genetic and non-genetic factors, and only the former are presumed to be inherited and thus suitable for the action of selection. Although increasing amounts of data suggest that non-genetic variability may be inherited, we have limited empirical data in animals. Here, we performed an artificial selection experiment using Drosophila melanogaster inbred lines. We quantified the response to selection for a decrease in chill coma recovery time and an increase in starvati...
Source: Journal of Experimental Biology - December 5, 2018 Category: Biology Authors: Menezes, B. F., Salces-Ortiz, J., Muller, H., Burlet, N., Martinez, S., Fablet, M., Vieira, C. Tags: RESEARCH ARTICLE Source Type: research

Innate visual preferences and behavioral flexibility in Drosophila [RESEARCH ARTICLE]
Martyna J. Grabowska, James Steeves, Julius Alpay, Matthew Van De Poll, Deniz Ertekin, and Bruno van Swinderen Visual decision making in animals is influenced by innate preferences as well as experience. Interaction between hard-wired responses and changing motivational states determines whether a visual stimulus is attractive, aversive or neutral. It is, however, difficult to separate the relative contribution of nature versus nurture in experimental paradigms, especially for more complex visual parameters such as the shape of objects. We used a closed-loop virtual reality paradigm for walking Drosophila to uncover innat...
Source: Journal of Experimental Biology - December 5, 2018 Category: Biology Authors: Grabowska, M. J., Steeves, J., Alpay, J., Van De Poll, M., Ertekin, D., van Swinderen, B. Tags: RESEARCH ARTICLE Source Type: research

Hif-1{alpha} paralogs play a role in the hypoxic ventilatory response of larval and adult zebrafish (Danio rerio) [RESEARCH ARTICLE]
Milica Mandic, Velislava Tzaneva, Vincent Careau, and Steve F. Perry Hypoxia inducible factor (Hif) 1α, an extensively studied transcription factor, is involved in the regulation of many biological processes in hypoxia including the hypoxic ventilatory response. In zebrafish, there are two paralogs of Hif-1α (Hif-1A and Hif-1B), but little is known about the specific roles or potential sub-functionalization of the paralogs in response to hypoxia. Using knockout lines of Hif-1α paralogs, we examined their involvement in the hypoxic ventilatory response, measured as ventilation frequency (fV) in larval and ...
Source: Journal of Experimental Biology - December 5, 2018 Category: Biology Authors: Mandic, M., Tzaneva, V., Careau, V., Perry, S. F. Tags: RESEARCH ARTICLE Source Type: research

How do baleen whales stow their filter? A comparative biomechanical analysis of baleen bending [RESEARCH ARTICLE]
Alexander J. Werth, Diego Rita, Michael V. Rosario, Michael J. Moore, and Todd L. Sformo Bowhead and right whale (balaenid) baleen filtering plates, longer in vertical dimension (≥3–4 m) than the closed mouth, presumably bend during gape closure. This has not been observed in live whales, even with scrutiny of video-recorded feeding sequences. To determine what happens to the baleen during gape closure, we conducted an integrative, multifactorial study including materials testing, functional (flow tank and kinematic) testing and histological examination. We measured baleen bending properties along the dorsov...
Source: Journal of Experimental Biology - December 4, 2018 Category: Biology Authors: Werth, A. J., Rita, D., Rosario, M. V., Moore, M. J., Sformo, T. L. Tags: RESEARCH ARTICLE Source Type: research

Bite force and cranial bone strain in four species of lizards [RESEARCH ARTICLE]
Callum F. Ross, Laura B. Porro, Anthony Herrel, Susan E. Evans, and Michael J. Fagan In vivo bone strain data provide direct evidence of strain patterns in the cranium during biting. Compared with those in mammals, in vivo bone strains in lizard skulls are poorly documented. This paper presents strain data from the skulls of Anolis equestris, Gekko gecko, Iguana iguana and Salvator merianae during transducer biting. Analysis of variance was used to investigate effects of bite force, bite point, diet, cranial morphology and cranial kinesis on strain magnitude. Within individuals, the most consistent determinants of varianc...
Source: Journal of Experimental Biology - December 4, 2018 Category: Biology Authors: Ross, C. F., Porro, L. B., Herrel, A., Evans, S. E., Fagan, M. J. Tags: RESEARCH ARTICLE Source Type: research

Deciphering function of the pulmonary arterial sphincters in loggerhead sea turtles (Caretta caretta) [RESEARCH ARTICLE]
Daniel Garcia-Parraga, Teresa Lorenzo, Tobias Wang, Jose-Luis Ortiz, Joaquin Ortega, Jose-Luis Crespo-Picazo, Julio Cortijo, and Andreas Fahlman To provide new insight into the pathophysiological mechanisms underlying gas emboli (GE) in bycaught loggerhead sea turtles (Caretta caretta), we investigated the vasoactive characteristics of the pulmonary and systemic arteries, and the lung parenchyma (LP). Tissues were opportunistically excised from recently dead animals for in vitro studies of vasoactive responses to four different neurotransmitters: acetylcholine (ACh; parasympathetic), serotonin (5HT), adrenaline (Adr; symp...
Source: Journal of Experimental Biology - December 4, 2018 Category: Biology Authors: Garcia-Parraga, D., Lorenzo, T., Wang, T., Ortiz, J.-L., Ortega, J., Crespo-Picazo, J.-L., Cortijo, J., Fahlman, A. Tags: RESEARCH ARTICLE Source Type: research

Vultures respond to challenges of near-ground thermal soaring by varying bank angle [RESEARCH ARTICLE]
Hannah J. Williams, Olivier Duriez, Mark D. Holton, Giacomo Dell'Omo, Rory P. Wilson, and Emily L. C. Shepard Many large birds rely on thermal soaring flight to travel cross-country. As such, they are under selective pressure to minimise the time spent gaining altitude in thermal updrafts. Birds should be able to maximise their climb rates by maintaining a position close to the thermal core through careful selection of bank angle and airspeed; however, there have been few direct measurements of either parameter. Here, we apply a novel methodology to quantify the bank angles selected by soaring birds using on-board magneto...
Source: Journal of Experimental Biology - December 3, 2018 Category: Biology Authors: Williams, H. J., Duriez, O., Holton, M. D., Dell'Omo, G., Wilson, R. P., Shepard, E. L. C. Tags: RESEARCH ARTICLE Source Type: research

The locomotor kinematics and ground reaction forces of walking giraffes [RESEARCH ARTICLE]
In this study, we examined the stride parameters and ground reaction forces from three adult giraffes in a zoological park, across a range of walking speeds. The patterns of GRFs during walking indicate that giraffes, similar to other mammalian quadrupeds, maintain a forelimb-biased weight distribution. The angular excursion of the neck has functional links with locomotor dynamics in giraffes, and was exaggerated at faster speeds. The horizontal accelerations of the neck and trunk were out of phase, compared with the vertical accelerations which were intermediate between in and out of phase. Despite possessing specialised ...
Source: Journal of Experimental Biology - December 3, 2018 Category: Biology Authors: Basu, C., Wilson, A. M., Hutchinson, J. R. Tags: RESEARCH ARTICLE Source Type: research

Comparison of spatiotemporal gait characteristics between vertical climbing and horizontal walking in primates [RESEARCH ARTICLE]
We examined footfall patterns, diagonality, speed, and stride length in eight species of primates across a range of body masses. We found that during vertical climbing primates slow down, keep more limbs in contact with the substrate at any one time, and increase the frequency of lateral sequence gaits compared to horizontal walking. Taken together these characteristics are assumed to increase stability during locomotion. Phylogenetic relatedness and body size differences have little influence on locomotor patterns observed across species. These data reject the idea that the suite of spatiotemporal gait features observed i...
Source: Journal of Experimental Biology - December 3, 2018 Category: Biology Authors: Granatosky, M. C., Schmitt, D., Hanna, J. Tags: RESEARCH ARTICLE Source Type: research

Interspecific variation in brain mitochondrial complex I and II capacity and ROS emission in marine sculpins [RESEARCH ARTICLE]
Gigi Y. Lau and Jeffrey G. Richards Environmental hypoxia presents a metabolic challenge for animals because it inhibits mitochondrial respiration and can lead to the generation of reactive oxygen species (ROS). We investigated the interplay between O2 use for aerobic respiration and ROS generation among sculpin fishes (Cottidae, Actinopterygii) that are known to vary in whole-animal hypoxia tolerance. We hypothesized that mitochondria from hypoxia tolerant sculpins would show more efficient O2 use with a higher phosphorylation efficiency and lower ROS emission. We showed that brain mitochondria from more hypoxia tolerant ...
Source: Journal of Experimental Biology - December 3, 2018 Category: Biology Authors: Lau, G. Y., Richards, J. G. Tags: RESEARCH ARTICLE Source Type: research

Detailed movement and laterality of fin-biting behaviour with special mouth morphology in Genyochromis mento in Lake Malawi [RESEARCH ARTICLE]
Yuichi Takeuchi, Hiroki Hata, Atsushi Maruyama, Takuto Yamada, Takuma Nishikawa, Makiko Fukui, Richard Zatha, Bosco Rusuwa, and Yoichi Oda Several vertebrates, including fish, exhibit behavioural laterality and associated morphological asymmetry. Laterality may increase individual fitness, and foraging strength, accuracy, and speed. However, little is known about which behaviours are affected by laterality or what fish species exhibit obvious laterality. Previous research on the predatory behaviour of the scale-eating Lake Tanganyika cichlid Perissodus microlepis indicates behavioural laterality that reflects asymmetric ja...
Source: Journal of Experimental Biology - December 3, 2018 Category: Biology Authors: Takeuchi, Y., Hata, H., Maruyama, A., Yamada, T., Nishikawa, T., Fukui, M., Zatha, R., Rusuwa, B., Oda, Y. Tags: RESEARCH ARTICLE Source Type: research

Hydrodynamics of linear acceleration in bluegill sunfish, Lepomis macrochirus [RESEARCH ARTICLE]
In this study, we examined the flow around bluegill sunfish Lepomis macrochirus during steady swimming and during forward acceleration, starting at a range of initial swimming speeds. We found that bluegill produce vortices with higher circulation during acceleration, indicating a higher force per tail beat, but they do not substantially redirect the force. We quantified the flow patterns using high speed video and particle image velocimetry and measured acceleration with small inertial measurement units attached to each fish. Even in steady tail beats, the fish accelerates slightly during each tail beat, and the magnitude...
Source: Journal of Experimental Biology - November 30, 2018 Category: Biology Authors: Wise, T. N., Schwalbe, M. A. B., Tytell, E. D. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

High accuracy at low frequency: detailed behavioural classification from accelerometer data [RESEARCH ARTICLE]
Jack Tatler, Phillip Cassey, and Thomas A. A. Prowse Accelerometers are a valuable tool for studying animal behaviour and physiology where direct observation is unfeasible. However, giving biological meaning to multivariate acceleration data is challenging. Here, we describe a method that reliably classifies a large number of behaviours using tri-axial accelerometer data collected at the low sampling frequency of 1 Hz, using the dingo (Canis dingo) as an example. We used out-of-sample validation to compare the predictive performance of four commonly used classification models (random forest, k-nearest neighbour, supp...
Source: Journal of Experimental Biology - November 29, 2018 Category: Biology Authors: Tatler, J., Cassey, P., Prowse, T. A. A. Tags: RESEARCH ARTICLE Source Type: research

The respiratory mechanics of the yacare caiman (Caiman yacare Daudine) [RESEARCH ARTICLE]
Michelle N. Reichert, Paulo R. C. de Oliveira, George M. P. R. Souza, Henriette G. Moranza, Wilmer A. Z. Restan, Augusto S. Abe, Wilfried Klein, and William K. Milsom The structure and function of crocodilian lungs are unique compared to other reptiles. We examine the extent to which this, and the semi-aquatic lifestyle of crocodilians affect their respiratory mechanics. We measured changes in intratracheal pressure in adult and juvenile caiman (Caiman yacare) during static and dynamic lung volume changes. Respiratory mechanics of juvenile caiman were additionally measured while floating in water and submerged at 30°, ...
Source: Journal of Experimental Biology - November 29, 2018 Category: Biology Authors: Reichert, M. N., de Oliveira, P. R. C., Souza, G. M. P. R., Moranza, H. G., Restan, W. A. Z., Abe, A. S., Klein, W., Milsom, W. K. Tags: RESEARCH ARTICLE Source Type: research

MicroRNAs regulate survival in oxygen-deprived environments [RESEARCH ARTICLE]
Simon G. English, Hanane Hadj-Moussa, and Kenneth B. Storey Some animals must endure prolonged periods of oxygen deprivation to survive. One such extreme model is the northern crayfish (Orconectes virilis), that regularly survives year-round hypoxic and anoxic stresses in its warm stagnant summer waters and in its cold, ice-locked winter waters. To elucidate the molecular underpinnings of anoxia resistance in this natural model, we surveyed the expression profiles of 76 highly conserved microRNAs in crayfish hepatopancreas and tail muscle from normoxic, acute 2 h anoxia, and chronic 20 h anoxia exposures. MicroR...
Source: Journal of Experimental Biology - November 28, 2018 Category: Biology Authors: English, S. G., Hadj-Moussa, H., Storey, K. B. Tags: RESEARCH ARTICLE Source Type: research