Fly eyes are not still: a motion illusion in Drosophila flight supports parallel visual processing [RESEARCH ARTICLE]
Wael Salem, Benjamin Cellini, Mark A. Frye, and Jean-Michel Mongeau Most animals shift gaze by a ‘fixate and saccade’ strategy, where the fixation phase stabilizes background motion. A logical prerequisite for robust detection and tracking of moving foreground objects, therefore, is to suppress the perception of background motion. In a virtual reality magnetic tether system enabling free yaw movement, Drosophila implemented a fixate and saccade strategy in the presence of a static panorama. When the spatial wavelength of a vertical grating was below the Nyquist wavelength of the compound eyes, flies drifted co...
Source: Journal of Experimental Biology - May 28, 2020 Category: Biology Authors: Salem, W., Cellini, B., Frye, M. A., Mongeau, J.-M. Tags: RESEARCH ARTICLE Source Type: research

Opportunities during challenging times: comparative studies using meta-analytic approaches and new grants to help early-career researchers [EDITORIAL]
Craig E. Franklin and Hans H. Hoppeler (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - May 27, 2020 Category: Biology Authors: Franklin, C. E., Hoppeler, H. H. Tags: EDITORIAL Source Type: research

The metabolic response to an immune challenge in a viviparous snake, Sistrurus miliarius [RESEARCH ARTICLE]
Craig M. Lind, Joseph Agugliaro, and Terence M. Farrell Mounting an immune response may be energetically costly and require the diversion of resources away from other physiological processes. Yet, both the metabolic cost of immune responses and the factors that impact investment priorities remain poorly described in many vertebrate groups. For example, although viviparity has evolved many times in vertebrates, the relationship between immune function and pregnancy has been disproportionately studied in placental mammals. To examine the energetic costs of immune activation and the modulation of immune function during pregn...
Source: Journal of Experimental Biology - May 27, 2020 Category: Biology Authors: Lind, C. M., Agugliaro, J., Farrell, T. M. Tags: RESEARCH ARTICLE Source Type: research

The aerodynamic force platform as an ergometer [METHODS [amp ] TECHNIQUES]
Marc E. Deetjen, Diana D. Chin, and David Lentink Animal flight requires aerodynamic power, which is challenging to determine accurately in vivo. Existing methods rely on approximate calculations based on wake flow field measurements, inverse dynamics approaches, or invasive muscle physiological recordings. In contrast, the external mechanical work required for terrestrial locomotion can be determined more directly by using a force platform as an ergometer. Based on an extension of the recent invention of the aerodynamic force platform, we now present a more direct method to determine the in vivo aerodynamic power by taki...
Source: Journal of Experimental Biology - May 27, 2020 Category: Biology Authors: Deetjen, M. E., Chin, D. D., Lentink, D. Tags: METHODS [amp ] TECHNIQUES Source Type: research

Mechanical fatigue fractures bivalve shells [RESEARCH ARTICLE]
R. L. Crane and M. W. Denny Mollusk shells protect against diverse environmental and predatory physical threats, from one-time impacts to chronic, low-magnitude stresses. The effectiveness of shells as armor is often quantified with a test of shell strength: increasing force is applied until catastrophic fracture. This test does not capture the potential role of fatigue, a process by which chronic or repeated, low-magnitude forces weaken and break a structure. We quantified the strength and fatigue resistance of California mussel (Mytilus californianus) shells. Shells were fatigue tested until catastrophic failure by eith...
Source: Journal of Experimental Biology - May 27, 2020 Category: Biology Authors: Crane, R. L., Denny, M. W. Tags: RESEARCH ARTICLE Source Type: research

Diving apart together: call propagation in diving long-finned pilot whales [RESEARCH ARTICLE]
Annebelle C. M. Kok, Lisette van Kolfshoten, James A. Campbell, Alexander M. von Benda-Beckmann, Patrick J. O. Miller, Hans Slabbekoorn, and Fleur Visser Group-living animals must communicate to stay in contact. In long-finned pilot whales, there is a trade-off between the benefits of foraging individually at depth and the formation of tight social groups at the surface. Using theoretical modelling and empirical data of tagged pairs within a group, we examined the potential of pilot whale social calls to reach dispersed group members during foraging periods. Both theoretical predictions and empirical data of tag pairs sho...
Source: Journal of Experimental Biology - May 27, 2020 Category: Biology Authors: Kok, A. C. M., van Kolfshoten, L., Campbell, J. A., von Benda-Beckmann, A. M., Miller, P. J. O., Slabbekoorn, H., Visser, F. Tags: RESEARCH ARTICLE Source Type: research

Ontogenetic variation in the hearing sensitivity of black sea bass (Centropristis striata) and the implications of anthropogenic sound on behavior and communication [RESEARCH ARTICLE]
This study is a first step in understanding the effects of anthropogenic noise on C. striata by determining the auditory bandwidth and thresholds of this species using auditory evoked potentials (AEPs), creating pressure and acceleration audiograms. These physiological tests were conducted on wild-caught C. striata in three size/age categories. Results showed that juvenile C. striata significantly had the lowest thresholds, with hearing sensitivity decreasing in the larger size classes. Furthermore, Centropristis striata has fairly sensitive hearing relative to other related species. Preliminary investigations into the mec...
Source: Journal of Experimental Biology - May 27, 2020 Category: Biology Authors: Stanley, J. A., Caiger, P. E., Phelan, B., Shelledy, K., Mooney, T. A., Van Parijs, S. M. Tags: RESEARCH ARTICLE Source Type: research

Polarized light sensitivity in Pieris rapae is dependent on both color and intensity [RESEARCH ARTICLE]
Adam J. Blake, Gina S. Hahn, Hayley Grey, Shelby A. Kwok, Deby McIntosh, and Gerhard Gries There is an ever increasing number of arthropod taxa shown to have polarization sensitivity throughout their compound eyes. However, the downstream processing of polarized reflections from objects is not well understood. The small white butterfly, Pieris rapae, has been demonstrated to exploit foliar polarized reflections, specifically the degree of linear polarization (DoLP), to recognize host plants. The well-described visual system of P. rapae includes several photoreceptor types (red, green, blue) that are sensitive to polarized ...
Source: Journal of Experimental Biology - May 27, 2020 Category: Biology Authors: Blake, A. J., Hahn, G. S., Grey, H., Kwok, S. A., McIntosh, D., Gries, G. Tags: RESEARCH ARTICLE Source Type: research

Colin James Pennycuick (1933-2019) [OBITUARY]
Anders Hedenström and Geoffrey Spedding (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - May 26, 2020 Category: Biology Authors: Hedenström, A., Spedding, G. Tags: OBITUARY Source Type: research

Fatigue pushes mussel shells to the brink over time [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - May 26, 2020 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

The effect of ecological factors on eye morphology in the western rainbowfish, Melanotaenia australis [RESEARCH ARTICLE]
Thomas J. Lisney, Shaun P. Collin, and Jennifer L. Kelley Ecological factors such as spatial habitat complexity and diet can explain variation in visual morphology, but few studies have sought to determine whether visual specialisation can occur among populations of the same species. We used a small Australian freshwater fish (the western rainbowfish, Melanotaenia australis) to determine whether populations showed variation in eye size and eye position, and whether this variation could be explained by environmental (light availability, turbidity) and ecological (predation risk, habitat complexity, invertebrate abundance) ...
Source: Journal of Experimental Biology - May 26, 2020 Category: Biology Authors: Lisney, T. J., Collin, S. P., Kelley, J. L. Tags: RESEARCH ARTICLE Source Type: research

Maximum aerodynamic force production by the wandering glider dragonfly (Pantala flavescens, Libellulidae) [RESEARCH ARTICLE]
Guanting Su, Robert Dudley, Tianyu Pan, Mengzong Zheng, Liansong Peng, and Qiushi Li Maximum whole-body force production can influence behavioral outcomes for volant taxa, and may also be relevant to aerodynamic optimization in microair vehicles. Here, we describe a new method for measuring maximum force production in free-flying animals, and present associated data for the wandering glider dragonfly. Flight trajectories were repeatedly acquired from pull-up responses by insects dropped in mid-air with submaximal loads attached beneath the center of body mass. Forces were estimated from calculations of the maximum time-ave...
Source: Journal of Experimental Biology - May 26, 2020 Category: Biology Authors: Su, G., Dudley, R., Pan, T., Zheng, M., Peng, L., Li, Q. Tags: RESEARCH ARTICLE Source Type: research

Effect of ambient temperature on sleep breathing phenotype in mice: the role of orexins [RESEARCH ARTICLE]
Chiara Berteotti, Viviana Lo Martire, Sara Alvente, Stefano Bastianini, Gabriele Matteoli, Alessandro Silvani, and Giovanna Zoccoli The loss of orexinergic neurons, releasing orexins, results in narcolepsy. Orexins participate in the regulation of many physiological functions, and their role as wake-promoting molecules has been widely described. Less is known about the involvement of orexins in body temperature and respiratory regulation. The aim of this study was to investigate whether orexin peptides modulate respiratory regulation as a function of ambient temperature (T°a) during different sleep stages. Respiratory ...
Source: Journal of Experimental Biology - May 26, 2020 Category: Biology Authors: Berteotti, C., Lo Martire, V., Alvente, S., Bastianini, S., Matteoli, G., Silvani, A., Zoccoli, G. Tags: RESEARCH ARTICLE Source Type: research

Effects of membrane fatty acid composition on cellular metabolism and oxidative stress in dermal fibroblasts from small and large breed dogs [RESEARCH ARTICLE]
Ana Gabriela Jimenez, Joshua D. Winward, Kenneth E. Walsh, and Alex M. Champagne There is ample evidence that cell membrane architecture contributes to metabolism and aging in animals, however the aspects of this architecture that determine the rate of metabolism and longevity are still being debated. The "membrane pacemaker" hypotheses of metabolism and aging, respectively, suggest that increased lipid unsaturation and large amounts of polyunsaturated fatty acids (PUFAs) in cell membranes increases the cellular metabolic rate as well as the vulnerability of the cell to oxidative damage, thus increasing organisma...
Source: Journal of Experimental Biology - May 26, 2020 Category: Biology Authors: Jimenez, A. G., Winward, J. D., Walsh, K. E., Champagne, A. M. Tags: RESEARCH ARTICLE Source Type: research

Hypoxia acclimation alters reactive oxygen species homeostasis and oxidative status in estuarine killifish (Fundulus heteroclitus) [RESEARCH ARTICLE]
We examined how exposure to acute hypoxia (2 kPa O2) and subsequent reoxygenation (to 20 kPa O2) affects redox status, oxidative damage, and antioxidant defenses in estuarine killifish (Fundulus heteroclitus), and whether these effects were ameliorated or potentiated by prolonged (28 day) acclimation to either constant hypoxia or intermittent cycles of nocturnal hypoxia (12 h normoxia: 12 h hypoxia). Acute hypoxia and reoxygenation led to some modest and transient changes in redox status, increases in oxidized glutathione, depletion of scavenging capacity, and oxidative damage to lipids in the skeletal muscle. The liver ha...
Source: Journal of Experimental Biology - May 26, 2020 Category: Biology Authors: Borowiec, B. G., Scott, G. R. Tags: RESEARCH ARTICLE Source Type: research

Mussels' acclimatization to high, variable temperatures is lost slowly upon transfer to benign conditions [RESEARCH ARTICLE]
This study explored the rate at which field-acclimatization states are lost when temperature variability is minimized during constant submersion. California mussels (Mytilus californianus) with different acclimatization states were collected from high- and low-zone sites (~12°C vs. ~5°C daily temperature ranges, respectively) and then kept submerged at 15°C for eight weeks. Each week, mussels’ cardiac thermal performance was measured as a metric of acclimatization state; critical (Tcrit) and flatline (FLT) temperatures were recorded. Across eight weeks of constant submersion high-zone mussels’ mean ...
Source: Journal of Experimental Biology - May 26, 2020 Category: Biology Authors: Moyen, N. E., Somero, G. N., Denny, M. W. Tags: RESEARCH ARTICLE Source Type: research

A novel microRNA and its PFK target control growth length in the freshwater shrimp (Neocaridina heteropoda) [RESEARCH ARTICLE]
Ran Li, Jieyang Weng, Liqi Ren, Xin Wang, Qinghao Meng, Liyan Wang, and Jinsheng Sun MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression and play roles in a wide range of physiological processes, including ontogenesis. Herein, we discovered a novel microRNA, novel miR-26, which inhibits translation of the phosphofructokinase (PFK) gene by targeting the 3’ untranslated region (UTR) of pfk directly, thereby inhibiting the molting and body length growth of the freshwater shrimp (Neocaridina heteropoda). Lowering expression of the PFK gene by RNA interference (RNAi) led to a longer ecdys...
Source: Journal of Experimental Biology - May 26, 2020 Category: Biology Authors: Li, R., Weng, J., Ren, L., Wang, X., Meng, Q., Wang, L., Sun, J. Tags: RESEARCH ARTICLE Source Type: research

Pygmy mouse songs reveal anatomical innovations underlying acoustic signal elaboration in rodents [RESEARCH ARTICLE]
Tobias Riede and Bret Pasch Elaborate animal communication displays are often accompanied by morphological and physiological innovations. In rodents, acoustic signals used in reproductive contexts are produced by two distinct mechanisms, but the underlying anatomy that facilitates such divergence is poorly understood. ‘Audible’ vocalizations with spectral properties between 500 Hz and 16 kHz are thought to be produced by flow-induced vocal fold vibrations, whereas ‘ultrasonic’ vocalizations with fundamental frequencies above 19 kHz are produced by an aerodynamic whistle mechanism. Baiomyine mice (ge...
Source: Journal of Experimental Biology - May 26, 2020 Category: Biology Authors: Riede, T., Pasch, B. Tags: RESEARCH ARTICLE Source Type: research

Discrete modulation of antipredatory and agonistic behaviors by sensory communication signals in juvenile crayfish [RESEARCH ARTICLE]
Alexis C. Exum, Lucky M. Sun, and Jens Herberholz We investigated how the exchange of sensory signals modulates the individual behaviors of juvenile crayfish in an anti-predatory context as well as during intraspecific agonistic encounters. We first compared crayfish housed in total sensory isolation or in pairs with access to chemical and visual cues. After one week of housing, we analyzed their individual responses to a visual danger signal while they were foraging. We found that crayfish previously housed in pairs with exchange of sensory signals responded to a simulated predator attack predominately with freezing behav...
Source: Journal of Experimental Biology - May 26, 2020 Category: Biology Authors: Exum, A. C., Sun, L. M., Herberholz, J. Tags: RESEARCH ARTICLE Source Type: research

Swallow mums push metabolic limits when they can keep cool [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - May 22, 2020 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Heat dissipation capacity influences reproductive performance in an aerial insectivore [RESEARCH ARTICLE]
Simon Tapper, Joseph J. Nocera, and Gary Burness Climatic warming is predicted to increase the frequency of extreme weather events, which may reduce an individual's capacity for sustained activity because of thermal limits. We tested whether the risk of overheating may limit parental provisioning of an aerial insectivorous bird in population decline. For many seasonally breeding birds, parents are thought to operate close to an energetic ceiling during the 2–3 week chick-rearing period. The factors determining the ceiling remain unknown, although it may be set by an individual's capacity to dissipate body heat ...
Source: Journal of Experimental Biology - May 22, 2020 Category: Biology Authors: Tapper, S., Nocera, J. J., Burness, G. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

Limits to sustained energy intake. XXXI. Effect of graded levels of dietary fat on lactation performance in Swiss mice [RESEARCH ARTICLE]
Yi Huang, Jazmin Osorio Mendoza, Catherine Hambly, Baoguo Li, Zengguang Jin, Li Li, Moshen Madizi, Sumei Hu, and John R. Speakman The heat dissipation limit theory predicts that lactating female mice consuming diets with lower specific dynamic action (SDA) should have enhanced lactation performance. Dietary fat has lower SDA than other macronutrients. Here we tested the effects of graded dietary fat levels on lactating Swiss mice. We fed females five diets varying in fat content from 8.3 to 66.6%. Offspring of mothers fed diets of 41.7% fat and above were heavier and fatter at weaning compared with those of 8.3 and 25% fa...
Source: Journal of Experimental Biology - May 22, 2020 Category: Biology Authors: Huang, Y., Mendoza, J. O., Hambly, C., Li, B., Jin, Z., Li, L., Madizi, M., Hu, S., Speakman, J. R. Tags: RESEARCH ARTICLE Source Type: research

A fast and effective method for dissecting parasitic spores: myxozoans as an example [METHODS [amp ] TECHNIQUES]
Qingxiang Gu, Yang Liu, Yanhua Zhai, and Zemao Gu Disassembling parasitic spores and acquiring the main subunits for analysis is a prerequisite for a deep understanding of the basic biology of parasites. Herein, we present a fast and efficient method to dissect myxospores in a few steps, which mainly involves sonication, and sucrose and Percoll density gradient ultracentrifugation. We tested our method on three myxozoan species and demonstrate that this method allows the dismembering of myxospores, and the isolation of intact and clean nematocysts and shell valves within 2 h at low cost. This new tool will facilitate...
Source: Journal of Experimental Biology - May 22, 2020 Category: Biology Authors: Gu, Q., Liu, Y., Zhai, Y., Gu, Z. Tags: METHODS [amp ] TECHNIQUES Source Type: research

Both sexes produce sounds in vocal fish species: testing the hypothesis in the pygmy gourami (labyrinth fishes) [RESEARCH ARTICLE]
Noemie Liesch and Friedrich Ladich In vocal fish species, males possess larger sound-generating organs and signal acoustically with pronounced sex-specific differences. Sound production is known in two out of three species of croaking gouramis (Trichopsis vittata and T. schalleri). The present study investigates sex-specific differences in sonic organs, vocalizing behaviour and sounds emitted in the third species, the pygmy gourami, T. pumila, in order to test the hypothesis that females are able to vocalize despite their less-developed sonic organs, and despite contradictory reports. Croaking gouramis stretch and pluck t...
Source: Journal of Experimental Biology - May 20, 2020 Category: Biology Authors: Liesch, N., Ladich, F. Tags: RESEARCH ARTICLE Source Type: research

On the regeneration of fish scales: structure and mechanical behavior [RESEARCH ARTICLE]
S. Ghods, S. Waddell, E. Weller, C. Renteria, H.-Y. Jiang, J. M. Janak, S. S. Mao, T. J. Linley, and D. Arola Fish scales serve as a dermal armor that provides protection from physical injury. Owing to a number of outstanding properties, fish scales are inspiring new concepts for layered engineered materials and next-generation flexible armors. Although past efforts have primarily focused on the structure and mechanical behavior of ontogenetic scales, the structure–property relationships of regenerated scales have received limited attention. In the present study, common carp (Cyprinus carpio) acquired from the wild ...
Source: Journal of Experimental Biology - May 20, 2020 Category: Biology Authors: Ghods, S., Waddell, S., Weller, E., Renteria, C., Jiang, H.- Y., Janak, J. M., Mao, S. S., Linley, T. J., Arola, D. Tags: RESEARCH ARTICLE Source Type: research

Feisty squid and fish flash back to dazzle predatory elephant seals [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - May 19, 2020 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Flash and grab: deep-diving southern elephant seals trigger anti-predator flashes in bioluminescent prey [RESEARCH ARTICLE]
Pauline Goulet, Christophe Guinet, Claudio Campagna, Julieta Campagna, Peter Lloyd Tyack, and Mark Johnson Bioluminescence, which occurs in approximately 80% of the world's mesopelagic fauna, can take the form of a low-intensity continuous glow (e.g. for counter-illumination or signalling) or fast repetitions of brighter anti-predatory flashes. The southern elephant seal (SES) is a major consumer of mesopelagic organisms, in particular the abundant myctophid fish, yet the fine-scale relationship between this predator's foraging behaviour and bioluminescent prey remains poorly understood. We hypothesised that brief, intens...
Source: Journal of Experimental Biology - May 19, 2020 Category: Biology Authors: Goulet, P., Guinet, C., Campagna, C., Campagna, J., Tyack, P. L., Johnson, M. Tags: RESEARCH ARTICLE Source Type: research

Neural dysfunction correlates with heat coma and CTmax in Drosophila but does not set the boundaries for heat stress survival [RESEARCH ARTICLE]
Lisa B. Jorgensen, R. Meldrum Robertson, and Johannes Overgaard When heated, insects lose coordinated movement followed by the onset of heat coma (CTmax). These traits are popular measures to quantify inter- and intraspecific differences in insect heat tolerance, and CTmax correlate well with current species distributions of insects, including Drosophila. Here we examined the function of the central nervous system (CNS) in five species of Drosophila with different heat tolerances, while they were exposed to either constant high temperature or a gradual increasing temperature (ramp). Tolerant species were able to preserve C...
Source: Journal of Experimental Biology - May 19, 2020 Category: Biology Authors: Jorgensen, L. B., Robertson, R. M., Overgaard, J. Tags: RESEARCH ARTICLE Source Type: research

Atrioventricular block, due to reduced ventricular excitability, causes the depression of fish heart rate in fish at critically high temperatures [RESEARCH ARTICLE]
Jaakko Haverinen and Matti Vornanen At critically high temperature, cardiac output in fish collapses due to depression of heart rate (bradycardia). However, the cause of bradycardia remains unresolved. To this end rainbow trout (Oncorhynchus mykiss; acclimated at +12°C) were exposed to acute warming, while electrocardiograms were recorded. From +12℃ to +25.3℃, electrical excitation between different parts of the heart was coordinated but above +25.3℃ atrial and ventricular beating rates became partly dissociated due to 2:1 atrioventricular (AV) block. With further warming atrial rate increased to the peak value o...
Source: Journal of Experimental Biology - May 19, 2020 Category: Biology Authors: Haverinen, J., Vornanen, M. Tags: RESEARCH ARTICLE Source Type: research

Cyber-frog leg leaps out of reality [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - May 18, 2020 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Magnetoreception in fishes: the effect of magnetic pulses on orientation of juvenile Pacific salmon [RESEARCH ARTICLE]
In this study, juvenile Chinook salmon (Oncorhynchus tshawytscha) were exposed to a brief but strong magnetic pulse capable of altering the magnetic dipole moment of biogenic magnetite. Orientation behaviour of pulsed fish and untreated control fish was then compared in a magnetic coil system under two conditions: (1) the local magnetic field and (2) a magnetic field that exists near the southern boundary of the natural oceanic range of Chinook salmon. In the local field, no significant difference existed between the orientation of the control and pulsed groups. By contrast, orientation of the two groups was significantly ...
Source: Journal of Experimental Biology - May 18, 2020 Category: Biology Authors: Naisbett-Jones, L. C., Putman, N. F., Scanlan, M. M., Noakes, D. L. G., Lohmann, K. J. Tags: RESEARCH ARTICLE Source Type: research

Learning of bimodal versus unimodal signals in restrained bumble bees [RESEARCH ARTICLE]
Andre J. Riveros, Anne S. Leonard, Wulfila Gronenberg, and Daniel R. Papaj Similar to animal communication displays, flowers emit complex signals that attract pollinators. Signal complexity could lead to higher cognitive load for pollinators, impairing performance, or might benefit them by facilitating learning, memory and decision making. Here, we evaluated learning and memory in foragers of the bumble bee Bombus impatiens trained to simple (unimodal) versus complex (bimodal) signals under restrained conditions. Use of a proboscis extension response protocol enabled us to control the timing and duration of stimuli presen...
Source: Journal of Experimental Biology - May 18, 2020 Category: Biology Authors: Riveros, A. J., Leonard, A. S., Gronenberg, W., Papaj, D. R. Tags: RESEARCH ARTICLE Source Type: research

In vitro virtual reality: an anatomically explicit musculoskeletal simulation powered by in vitro muscle using closed-loop tissue-software interaction [METHODS [amp ] TECHNIQUES]
Christopher T. Richards and Enrico A. Eberhard Muscle force–length dynamics are governed by intrinsic contractile properties, motor stimulation and mechanical load. Although intrinsic properties are well characterised, physiologists lack in vitro instrumentation to account for combined effects of limb inertia, musculoskeletal architecture and contractile dynamics. We introduce in vitro virtual reality (in vitro-VR) which enables in vitro muscle tissue to drive a musculoskeletal jumping simulation. In hardware, muscle force from a frog plantaris was transmitted to a software model where joint torques, inertia and gro...
Source: Journal of Experimental Biology - May 18, 2020 Category: Biology Authors: Richards, C. T., Eberhard, E. A. Tags: Comparative biomechanics of movement METHODS [amp ] TECHNIQUES Source Type: research

An {alpha}7-related nicotinic acetylcholine receptor mediates the ciliary arrest response in pharyngeal gill slits of Ciona [RESEARCH ARTICLE]
Kei Jokura, Junko M. Nishino, Michio Ogasawara, and Atsuo Nishino Ciliary movement is a fundamental process to support animal life, and the movement pattern may be altered in response to external stimuli under the control of nervous systems. Juvenile and adult ascidians have ciliary arrays around their pharyngeal gill slits (stigmata), and continuous beating is interrupted for seconds by mechanical stimuli on other parts of the body. Although it has been suggested that neural transmission to evoke ciliary arrest is cholinergic, its molecular basis has not yet been elucidated in detail. Here, we attempted to clarify the mo...
Source: Journal of Experimental Biology - May 18, 2020 Category: Biology Authors: Jokura, K., Nishino, J. M., Ogasawara, M., Nishino, A. Tags: RESEARCH ARTICLE Source Type: research

Effect of stimulus height on cockroach optomotor response [RESEARCH ARTICLE]
Juha Nuutila, Anna E. Honkanen, Kyösti Heimonen, and Matti Weckström Using tethered American cockroaches walking on a trackball in a spherical virtual reality environment, we tested optomotor responses to horizontally moving black-and-white gratings of different vertical extent under six different light intensities. We found that shortening the vertical extent of the wide-field stimulus grating within a light level weakened response strength, reduced average velocity and decreased angular walking distance. Optomotor responses with the vertically shortened stimuli persisted down to light intensity levels of 0.05 l...
Source: Journal of Experimental Biology - May 18, 2020 Category: Biology Authors: Nuutila, J., Honkanen, A. E., Heimonen, K., Weckström, M. Tags: RESEARCH ARTICLE Source Type: research

The OxymiR response to oxygen limitation: a comparative microRNA perspective [REVIEW]
Hanane Hadj-Moussa and Kenneth B. Storey From squid at the bottom of the ocean to humans at the top of mountains, animals have adapted to diverse oxygen-limited environments. Surviving these challenging conditions requires global metabolic reorganization that is orchestrated, in part, by microRNAs that can rapidly and reversibly target all biological functions. Herein, we review the involvement of microRNAs in natural models of anoxia and hypoxia tolerance, with a focus on the involvement of oxygen-responsive microRNAs (OxymiRs) in coordinating the metabolic rate depression that allows animals to tolerate reduced oxygen l...
Source: Journal of Experimental Biology - May 18, 2020 Category: Biology Authors: Hadj-Moussa, H., Storey, K. B. Tags: REVIEW Source Type: research

Correction: Exposure to hot temperatures during lactation in Swiss mice stunts offspring growth and decreases future reproductive performance of female offspring [CORRECTION]
Meng-Huan Bao, Li-Bing Chen, Catherine Hambly, John R. Speakman, and Zhi-Jun Zhao (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - May 15, 2020 Category: Biology Authors: Bao, M.-H., Chen, L.-B., Hambly, C., Speakman, J. R., Zhao, Z.-J. Tags: CORRECTION Source Type: research

Route learning during tandem running in the rock ant Temnothorax albipennis [RESEARCH ARTICLE]
Takao Sasaki, Leo Danczak, Beth Thompson, Trisha Morshed, and Stephen C. Pratt Many animals use information from conspecifics to change their behavior in adaptive ways. When a rock ant, Temnothorax albipennis, finds food, she returns to her colony and uses a method called tandem running to lead nestmates, one at a time, from the nest to the food. In this way, naive ants can learn the location of a food source. Less clear is whether they also learn navigational cues that guide them from nest to food, although this is often assumed. We tested this idea by tracing the routes of individually marked ants as they followed tande...
Source: Journal of Experimental Biology - May 15, 2020 Category: Biology Authors: Sasaki, T., Danczak, L., Thompson, B., Morshed, T., Pratt, S. C. Tags: RESEARCH ARTICLE Source Type: research

Terrestrial acclimation and exercise lead to bone functional response in Polypterus pectoral fins [RESEARCH ARTICLE]
Trina Y. Du and Emily M. Standen The ability of bones to sense and respond to mechanical loading is a central feature of vertebrate skeletons. However, the functional demands imposed on terrestrial and aquatic animals differ vastly. The pectoral girdle of the basal actinopterygian fish Polypterus senegalus was previously shown to exhibit plasticity following terrestrial acclimation, but the pectoral fin itself has yet to be examined. We investigated skeletal plasticity in the pectoral fins of Polypterus after exposure to terrestrial loading. Juvenile fish were divided into three groups: a control group was kept under aquat...
Source: Journal of Experimental Biology - May 15, 2020 Category: Biology Authors: Du, T. Y., Standen, E. M. Tags: RESEARCH ARTICLE Source Type: research

Asymmetrical gait kinematics of free-ranging callitrichines in response to changes in substrate diameter and orientation [RESEARCH ARTICLE]
Noah T. Dunham, Allison McNamara, Liza J. Shapiro, Taylor Phelps, and Jesse W. Young Arboreal environments present considerable biomechanical challenges for animals moving and foraging among substrates varying in diameter, orientation, and compliance. Most studies of quadrupedal gait kinematics in primates and other arboreal mammals have focused on symmetrical walking gaits and the significance of diagonal sequence gaits. Considerably less research has examined asymmetrical gaits, despite their prevalence in small-bodied arboreal taxa. Here we examine whether and how free-ranging callitrichine primates adjust asymmetrical ...
Source: Journal of Experimental Biology - May 15, 2020 Category: Biology Authors: Dunham, N. T., McNamara, A., Shapiro, L. J., Phelps, T., Young, J. W. Tags: RESEARCH ARTICLE Source Type: research

Functional effect of vaterite - The presence of an alternative crystalline structure in otoliths alters escape kinematics of the brown trout [RESEARCH ARTICLE]
Matthias Vignon and Jean-Christophe Aymes The fast-start escape response is the main locomotor behavior observed in fish to evade predatory attacks and thereby increase their probability of survival. Thus far, this high speed sensory motor control has been extensively studied in relation to extrinsic factors. In contrast, there has been surprisingly little consideration for intrinsic individuals factors that can mediate sensorial perception, such as inter-individual variability in mechanosensory systems. The inner ear of teleost fishes is composed of otoliths that play an important role in hearing and balance functions. Wh...
Source: Journal of Experimental Biology - May 15, 2020 Category: Biology Authors: Vignon, M., Aymes, J.-C. Tags: RESEARCH ARTICLE Source Type: research

Complex multi-modal sensory integration and context specificity in colour preferences of a pierid butterfly [RESEARCH ARTICLE]
G. S. Balamurali, Saloni Rose, Hema Somanathan, and Ullasa Kodandaramaiah Innate colour preferences in insects were long considered to be a non-flexible representation of a floral ‘search image’ guiding insects to flowers during initial foraging trips. However, these colour preferences have recently been shown to be modulated by multi-sensory integration of information. Using experiments on the butterfly Catopsilia pomona (Common Emigrant), we demonstrate that cross-modal integration of information not only affects colour preferences but also colour learning, and in a sex-specific manner. We show that spontaneo...
Source: Journal of Experimental Biology - May 15, 2020 Category: Biology Authors: Balamurali, G. S., Rose, S., Somanathan, H., Kodandaramaiah, U. Tags: RESEARCH ARTICLE Source Type: research

Reduced exploration capacity despite brain volume increase in warm acclimated common minnow [RESEARCH ARTICLE]
Libor Zavorka, Barbara Koeck, Tiffany A. Armstrong, Mustafa Soganci, Amelie Crespel, and Shaun S. Killen While evidence suggests that warming may impact cognition of ectotherms, the underlying mechanisms remain poorly understood. A possible, but rarely considered mechanism is that metabolic response of ectotherms to warming associate with changes in brain morphology and functioning. Here we compared aerobic metabolism, volume of brain, boldness, and accuracy of maze solving of common minnows (Phoxinus phoxinus) acclimated for eight months to either their current optimal natural (14 °C) or warm (20 °C) water tempera...
Source: Journal of Experimental Biology - May 15, 2020 Category: Biology Authors: Zavorka, L., Koeck, B., Armstrong, T. A., Soganci, M., Crespel, A., Killen, S. S. Tags: RESEARCH ARTICLE Source Type: research

Spontaneous quantity discrimination of artificial flowers by foraging honeybees [RESEARCH ARTICLE]
Scarlett R. Howard, Jürgen Schramme, Jair E. Garcia, Leslie Ng, Aurore Avargues-Weber, Andrew D. Greentree, and Adrian G. Dyer Many animals need to process numerical and quantity information in order to survive. Spontaneous quantity discrimination allows differentiation between two or more quantities without reinforcement or prior training on any numerical task. It is useful for assessing food resources, aggressive interactions, predator avoidance and prey choice. Honeybees have previously demonstrated landmark counting, quantity matching, use of numerical rules, quantity discrimination and arithmetic, but have not been...
Source: Journal of Experimental Biology - May 14, 2020 Category: Biology Authors: Howard, S. R., Schramme, J., Garcia, J. E., Ng, L., Avargues-Weber, A., Greentree, A. D., Dyer, A. G. Tags: RESEARCH ARTICLE Source Type: research

Does the New Zealand rockwren (Xenicus gilviventris) hibernate? [RESEARCH ARTICLE]
In this study, we examined the thermal physiology of the endangered New Zealand rockwren (Xenicus gilviventris), a member of the Acanthisittidae, a family unique to New Zealand. This family, derived from Gondwana, is thought to be the sister taxon to all other passerines. Rockwrens permanently reside above the climatic timberline at altitudes from 1000 to 2900 m in the mountains of South Island. They feed on invertebrates and in winter face ambient temperatures far below freezing and deep deposits of snow. Their body temperature and rate of metabolism are highly variable. The rockwrens in our study regulated their bod...
Source: Journal of Experimental Biology - May 14, 2020 Category: Biology Authors: McNab, B. K., Weston, K. A. Tags: RESEARCH ARTICLE Source Type: research

A simple device to immobilize protists for electrophysiology and microinjection [METHODS [amp ] TECHNIQUES]
We present a simple device to mechanically immobilize motile cells such as ciliates. It can be used in particular for intracellular electrophysiology and microinjection. A transparent filter with holes smaller than the specimen is stretched over an outlet. A flow is induced by either a peristaltic pump or a depressurized tank, mechanically entraining cells to the bottom, where they immobilize against the filter. The cells start swimming again as soon as the flow is stopped. We demonstrate the device by recording action potentials in Paramecium and injecting a fluorescent dye in the cytosol. (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - May 14, 2020 Category: Biology Authors: Kulkarni, A., Elices, I., Escoubet, N., Pontani, L.-L., Prevost, A. M., Brette, R. Tags: METHODS [amp ] TECHNIQUES Source Type: research

Alkaline guts protect sea urchin larvae from infection [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - May 13, 2020 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Alkaline guts contribute to immunity during exposure to acidified seawater in the sea urchin larva [RESEARCH ARTICLE]
Meike Stumpp, Inga Petersen, Femke Thoben, Jia-Jiun Yan, Matthias Leippe, and Marian Y. Hu Larval stages of members of the Abulacraria superphylum including echinoderms and hemichordates have highly alkaline midguts. To date, the reason for the evolution of such extreme pH conditions in the gut of these organisms remains unknown. Here, we test the hypothesis that, analogous to the acidic stomachs of vertebrates, these alkaline conditions may represent a first defensive barrier to protect from environmental pathogens. pH-optimum curves for five different species of marine bacteria demonstrated a rapid decrease in prolifera...
Source: Journal of Experimental Biology - May 13, 2020 Category: Biology Authors: Stumpp, M., Petersen, I., Thoben, F., Yan, J.-J., Leippe, M., Hu, M. Y. Tags: RESEARCH ARTICLE Source Type: research

The sonar beam of Macrophyllum macrophyllum implies ecological adaptation under phylogenetic constraint [RESEARCH ARTICLE]
Mads Nedergaard Olsen, Annemarie Surlykke, and Lasse Jakobsen All animals are adapted to their ecology within the bounds of their evolutionary heritage. Echolocating bats clearly show such adaptations and boundaries through their biosonar call design. Adaptations include not only the overall time-frequency structure, but also the shape of the emitted echolocation beam. Macrophyllum macrophyllum is unique within the phyllostomid family, being the only species to predominantly hunt for insects in the open, on or above water and as such it presents an interesting case for comparing the impact of phylogeny and ecology as it or...
Source: Journal of Experimental Biology - May 12, 2020 Category: Biology Authors: Olsen, M. N., Surlykke, A., Jakobsen, L. Tags: RESEARCH ARTICLE Source Type: research

Conversation moves on: revisiting early-career researchers and a new focus on fieldwork [EDITORIAL]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - May 11, 2020 Category: Biology Authors: Knight, K. Tags: EDITORIAL Source Type: research