Cutaneous sensory feedback from paw pads affects lateral balance control during split-belt locomotion in the cat [RESEARCH ARTICLE]
Hangue Park, Elizaveta M. Latash, Yaroslav I. Molkov, Alexander N. Klishko, Alain Frigon, Stephen P. DeWeerth, and Boris I. Prilutsky Cutaneous sensory feedback from the paw pads plays an important role in regulating body balance, especially in challenging environments like ladder or slope walking. Here, we investigated the contribution of cutaneous sensory feedback from the paw pads to balance control in cats stepping on a split-belt treadmill. Fore- and hindpaws were anesthetized unilaterally using lidocaine injections. We evaluated body balance in intact and compromised cutaneous feedback conditions during split-belt lo...
Source: Journal of Experimental Biology - July 15, 2019 Category: Biology Authors: Park, H., Latash, E. M., Molkov, Y. I., Klishko, A. N., Frigon, A., DeWeerth, S. P., Prilutsky, B. I. Tags: RESEARCH ARTICLE Source Type: research

Whispering southern right whale mums and calves seek refuge in surf [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - July 11, 2019 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Acoustic crypsis in southern right whale mother-calf pairs: infrequent, low-output calls to avoid predation? [SHORT COMMUNICATION]
Mia L. K. Nielsen, Lars Bejder, Simone K. A. Videsen, Fredrik Christiansen, and Peter T. Madsen Southern right whales (Eubalaena australis) invest substantial amounts of energy in their calves, while facing the risk of having them predated upon by eavesdropping killer whales (Orcinus orca). We tested the hypothesis that southern right whale mother–calf pairs employ acoustic crypsis to reduce acoustic detectability by such predators. Specifically, we deployed multi-sensor DTAGs on nine lactating whales for a total of 62.9 h in a Western Australian breeding ground, and used a SoundTrap to estimate the concomitant...
Source: Journal of Experimental Biology - July 11, 2019 Category: Biology Authors: Nielsen, M. L. K., Bejder, L., Videsen, S. K. A., Christiansen, F., Madsen, P. T. Tags: SHORT COMMUNICATION Source Type: research

Ocellate river stingrays munch like some rats [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - July 10, 2019 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Energy turnover in mammalian skeletal muscle in contractions mimicking locomotion: effects of stimulus pattern on work, impulse and energetic cost and efficiency [RESEARCH ARTICLE]
Nancy A. Curtin, Roger C. Woledge, Timothy G. West, David Goodwin, Richard J. Piercy, and Alan M. Wilson Active muscle performs various mechanical functions during locomotion: work output during shortening, work absorption when resisting (but not preventing) lengthening, and impulse (force–time integral) whenever there is active force. The energetic costs of these functions are important components in the energy budget during locomotion. We investigated how the pattern of stimulation and movement affects the mechanics and energetics of muscle fibre bundles isolated from wild rabbits (Oryctolagus cuniculus). The fibr...
Source: Journal of Experimental Biology - July 10, 2019 Category: Biology Authors: Curtin, N. A., Woledge, R. C., West, T. G., Goodwin, D., Piercy, R. J., Wilson, A. M. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

Shearing overbite and asymmetrical jaw motions facilitate food breakdown in a freshwater stingray, Potamotrygon motoro [RESEARCH ARTICLE]
J. D. Laurence-Chasen, Jason B. Ramsay, and Elizabeth L. Brainerd Many species of fish process their prey with cyclic jaw motions that grossly resemble those seen in mammalian mastication, despite starkly different tooth and jaw morphologies. The degree of similarity between the processing behaviors of these disparate taxa has implications for our understanding of convergence in vertebrate feeding systems. Here, we used XROMM (X-ray reconstruction of moving morphology) to investigate prey processing behavior of Potamotrygon motoro, the ocellate river stingray, which has recently been found to employ asymmetrical, shearing...
Source: Journal of Experimental Biology - July 10, 2019 Category: Biology Authors: Laurence-Chasen, J. D., Ramsay, J. B., Brainerd, E. L. Tags: RESEARCH ARTICLE Source Type: research

Auditory evoked potentials of the plainfin midshipman fish (Porichthys notatus): Implications for directional hearing [RESEARCH ARTICLE]
Andrew D. Brown, Ruiyu Zeng, and Joseph A. Sisneros The plainfin midshipman (Porichthys notatus) is an acoustically communicative teleost fish. Here we evaluated auditory evoked potentials (AEPs) in reproductive female midshipman exposed to tones at or near dominant frequencies of the male midshipman advertisement call. An initial series of experiments characterized AEPs at behaviorally relevant suprathreshold sound levels (130-140 dB SPL re: 1 µPa). AEPs decreased in magnitude with increasing stimulus frequency and featured a stereotyped component at twice the stimulus frequency. Recording electrode position was var...
Source: Journal of Experimental Biology - July 10, 2019 Category: Biology Authors: Brown, A. D., Zeng, R., Sisneros, J. A. Tags: RESEARCH ARTICLE Source Type: research

Fatiguing stimulation increases curvature of the force-velocity relation in isolated fast-twitch and slow-twitch rat muscles [RESEARCH ARTICLE]
In conclusion, fatigue-induced loss of power is strongly associated with an increased curvature of the force-velocity relationship, particularly in slow-twitch muscles. (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - July 10, 2019 Category: Biology Authors: Kristensen, A. M., Nielsen, O. B., Pedersen, T. H., Overgaard, K. Tags: RESEARCH ARTICLE Source Type: research

Elbows key for walkers efficiency [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - July 9, 2019 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Straight arm walking, bent arm running: gait-specific elbow angles [RESEARCH ARTICLE]
Andrew K. Yegian, Yanish Tucker, Stephen Gillinov, and Daniel E. Lieberman Stereotypically, walking and running gaits in humans exhibit different arm swing behavior: during walking, the arm is kept mostly straight, while during running, the arm is bent at the elbow. The mechanism for this behavioral difference has not been explored before. We hypothesized that a mechanical tradeoff exists between the shoulder joint and the elbow joint. Bending the elbow reduces the radius of gyration of the arm and reduces shoulder muscle torque, but at the price of increasing elbow torque. We predicted that the mechanical tradeoff would ...
Source: Journal of Experimental Biology - July 9, 2019 Category: Biology Authors: Yegian, A. K., Tucker, Y., Gillinov, S., Lieberman, D. E. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

Experimental evolution of response to anoxia in Drosophila: recovery of locomotion following CO2 or N2 exposure [RESEARCH ARTICLE]
We examined three populations of Drosophila melanogaster (designated B) that have been inadvertently under selection for rapid recovery from CO2 exposure for nearly 40 years (around 1,000 generations) resulting from routine maintenance practices. We contrasted CO2 and N2 (presumed a less reactive gas) knockdown and recovery times of these B flies with six populations of common ancestry (A and C populations) that were not exposed to CO2 over the same period. We found that B populations showed faster and more consistent locomotor recovery than A or C populations after CO2 knockdown, a result also observed with N2 knockdown. ...
Source: Journal of Experimental Biology - July 8, 2019 Category: Biology Authors: Xiao, C., Fard, N. B., Brzezinski, K., Robertson, R. M., Chippindale, A. K. Tags: RESEARCH ARTICLE Source Type: research

Mitochondrial genotype influences the response to cold stress in the European green crab Carcinus maenas [RESEARCH ARTICLE]
Aidan F. Coyle, Erin R. Voss, Carolyn K. Tepolt, and David B. Carlon Hybrid zones provide natural experiments in recombination within and between genomes that may have strong effects on organismal fitness. On the East Coast of North America, two distinct lineages of the European green crab (Carcinus maenas) have been introduced in the last two centuries. These two lineages with putatively different adaptive properties have hybridized along the coast of the eastern Gulf of Maine, producing new nuclear and mitochondrial combinations that show clinal variation correlated with water temperature. To test the hypothesis that mit...
Source: Journal of Experimental Biology - July 8, 2019 Category: Biology Authors: Coyle, A. F., Voss, E. R., Tepolt, C. K., Carlon, D. B. Tags: RESEARCH ARTICLE Source Type: research

The dynamics between limited-term and lifelong coinfecting bacterial parasites in wild rodent hosts [RESEARCH ARTICLE]
Anat Eidelman, Carmit Cohen, Alvaro Navarro-Castilla, Serina Filler, Ricardo Gutierrez, Enav Bar-Shira, Naama Shahar, Mario Garrido, Snir Halle, Yoav Romach, Isabel Barja, Severine Tasker, Shimon Harrus, Aharon Friedman, and Hadas Hawlena Interactions between coinfecting parasites1 may take various forms, either direct or indirect, facilitative or competitive, and may be mediated by either bottom-up or top-down mechanisms. While each form of interaction leads to different evolutionary and ecological outcomes, it is challenging to tease them apart throughout the infection period. To establish the first step towards a mechan...
Source: Journal of Experimental Biology - July 8, 2019 Category: Biology Authors: Eidelman, A., Cohen, C., Navarro-Castilla, A., Filler, S., Gutierrez, R., Bar-Shira, E., Shahar, N., Garrido, M., Halle, S., Romach, Y., Barja, I., Tasker, S., Harrus, S., Friedman, A., Hawlena, H. Tags: RESEARCH ARTICLE Source Type: research

Evaluating the physiological significance of hypoxic hyperventilation in larval zebrafish (Danio rerio) [RESEARCH ARTICLE]
Yihang K. Pan, Milica Mandic, Alex M. Zimmer, and Steve F. Perry In water-breathing fishes, the hypoxic ventilatory response (HVR) represents an increase in water flow over the gills during exposure to lowered ambient O2 levels. The HVR is a critical defense mechanism that serves to delay the negative consequences of hypoxia on aerobic respiration. However, the physiological significance of the HVR in larval fishes is unclear as they do not have a fully developed gill and rely primarily on cutaneous gas transfer. Using larval zebrafish (4, 7, 10 and 15 days post-fertilization; dpf), we examined HVR under three levels...
Source: Journal of Experimental Biology - July 5, 2019 Category: Biology Authors: Pan, Y. K., Mandic, M., Zimmer, A. M., Perry, S. F. Tags: RESEARCH ARTICLE Source Type: research

Molecular mechanisms for intestinal HCO3- secretion and its regulation by guanylin in seawater-acclimated eels [RESEARCH ARTICLE]
Yoshio Takei, Marty K. S. Wong, and Masaaki Ando The intestine of marine teleosts secretes HCO3– into the lumen and precipitates Ca2+ and Mg2+ in the imbibed seawater as carbonates to decrease luminal fluid osmolality and facilitate water absorption. However, the hormonal regulation of HCO3– secretion is largely unknown. Here, mucosally added guanylin (GN) increased HCO3– secretion, measured by pH-stat, across isolated seawater-acclimated eel intestine bathed in saline at pH 7.4 (5% CO2). The effect of GN on HCO3– secretion was slower than that on the short-circuit current, and the time course...
Source: Journal of Experimental Biology - July 5, 2019 Category: Biology Authors: Takei, Y., Wong, M. K. S., Ando, M. Tags: RESEARCH ARTICLE Source Type: research

Developmental plasticity in metabolism but not in energy reserve accumulation in a seasonally polyphenic butterfly [RESEARCH ARTICLE]
Sami M. Kivelä, Karl Gotthard, and Philipp Lehmann The evolution of seasonal polyphenisms (discrete phenotypes in different annual generations) associated with alternative developmental pathways of diapause (overwintering) and direct development is favoured in temperate insects. Seasonal life history polyphenisms are common and include faster growth and development under direct development than in diapause. However, the physiological underpinnings of this difference remain poorly known despite its significance for understanding the evolution of polyphenisms. We measured respiration and metabolic rates through the penult...
Source: Journal of Experimental Biology - July 5, 2019 Category: Biology Authors: Kivelä, S. M., Gotthard, K., Lehmann, P. Tags: RESEARCH ARTICLE Source Type: research

Characterization of an evolutionarily conserved calcitonin signalling system in a lophotrochozoan, the Pacific oyster (Crassostrea gigas) [RESEARCH ARTICLE]
Julie Schwartz, Emilie Realis-Doyelle, Marie-Pierre Dubos, Benjamin Lefranc, Jerome Leprince, and Pascal Favrel In Protostoma, the diuretic hormone 31 (DH31) signalling system was long considered as the orthologue of the chordate calcitonin (CT) signalling system. Using the Pacific oyster (Crassostrea gigas) transcriptomic database GigaTON, we characterized seven G-protein-coupled receptors (GPCRs) named Cragi-CTR1–7 and phylogenetically related to chordate CT receptors (CTRs) and to protostome DH31 receptors. Two CT precursors (Cragi-CTP1 and Cragi-CTP2) containing two CT-type peptides and encoded by two distinct g...
Source: Journal of Experimental Biology - July 5, 2019 Category: Biology Authors: Schwartz, J., Realis-Doyelle, E., Dubos, M.-P., Lefranc, B., Leprince, J., Favrel, P. Tags: RESEARCH ARTICLE Source Type: research

Hornets possess long-lasting olfactory memories [RESEARCH ARTICLE]
Zhiwen Gong, Ken Tan, and James C. Nieh The ability of animals to learn and remember is an important adaptation for coping with environmental changes. The fitness benefits provided by these cognitive skills, in conjunction with social behaviours, contribute to the success of social insects. How these abilities are shared among the different castes and the long-term persistence of memory are now being elucidated in diverse systems, work that should shed light on general principles underlying cognitive evolution. Here, we provide the first evidence of olfactory learning and long-term olfactory memory in all three castes of ...
Source: Journal of Experimental Biology - July 5, 2019 Category: Biology Authors: Gong, Z., Tan, K., Nieh, J. C. Tags: Neuroethology RESEARCH ARTICLE Source Type: research

The role of lateral optic flow cues in hawkmoth flight control [RESEARCH ARTICLE]
Anna Stöckl, Rebecca Grittner, and Keram Pfeiffer Flying animals require sensory feedback on changes of their body position, as well as on their distance from nearby objects. The apparent image motion, or optic flow, which is generated as animals move through the air, can provide this information. Flight tunnel experiments have been crucial for our understanding of how insects use optic flow for flight control in confined spaces. However, previous work mainly focused on species from two insect orders: Hymenoptera and Diptera. We therefore set out to investigate whether the previously described control strategies to navi...
Source: Journal of Experimental Biology - July 5, 2019 Category: Biology Authors: Stöckl, A., Grittner, R., Pfeiffer, K. Tags: RESEARCH ARTICLE Source Type: research

Salmonid gene expression biomarkers indicative of physiological responses to changes in salinity and temperature, but not dissolved oxygen [RESEARCH ARTICLE]
Aimee Lee S. Houde, Arash Akbarzadeh, Oliver P. Günther, Shaorong Li, David A. Patterson, Anthony P. Farrell, Scott G. Hinch, and Kristina M. Miller An organism's ability to respond effectively to environmental change is critical to its survival. Yet, life stage and overall condition can dictate tolerance thresholds to heightened environmental stressors, such that stress may not be equally felt across individuals and at all times. Also, the transcriptional responses induced by environmental changes can reflect both generalized responses as well as others that are highly specific to the type of change being experienced. ...
Source: Journal of Experimental Biology - July 5, 2019 Category: Biology Authors: Houde, A. L. S., Akbarzadeh, A., Günther, O. P., Li, S., Patterson, D. A., Farrell, A. P., Hinch, S. G., Miller, K. M. Tags: RESEARCH ARTICLE Source Type: research

Short-term, but not long-term, increased day time workload leads to decreased night time energetics in a free living song bird [RESEARCH ARTICLE]
Marcel E. Visser, Coby van Dooremalen, Barbara M. Tomotani, Andrey Bushuev, Harro A. J. Meijer, Luc te Marvelde, and Phillip Gienapp Reproduction is energetically expensive and to obtain sufficient energy, animals can either alter their metabolic system over time to increase energy intake (increased-intake hypothesis), or reallocate energy from maintenance processes (compensation hypothesis). The first hypothesis predicts a positive relationship between basal metabolic rate (BMR) and energy expenditure (DEE) because of the higher energy demands of the metabolic system in rest. The second hypothesis predicts a trade-off bet...
Source: Journal of Experimental Biology - July 5, 2019 Category: Biology Authors: Visser, M. E., van Dooremalen, C., Tomotani, B. M., Bushuev, A., Meijer, H. A. J., te Marvelde, L., Gienapp, P. Tags: RESEARCH ARTICLE Source Type: research

Contribution of the Achilles tendon to force potentiation in stretch-shortening cycle [RESEARCH ARTICLE]
Atsuki Fukutani, Andrew Sawatsky, Timothy Leonard, and Walter Herzog Muscle force during concentric contractions is potentiated by a preceding eccentric contraction; a phenomenon known as the stretch-shortening cycle (SSC) effect. Tendon elongation is often considered to be the primary factor for this force potentiation. However, direct examination of the influence of tendon elongation on the SSC effect has not been made. The aim of this study was to evaluate the contribution of tendon elongation to the SSC effect by comparing the magnitude of the SSC effect in the rat soleus with and without the Achilles tendon. The rat s...
Source: Journal of Experimental Biology - July 5, 2019 Category: Biology Authors: Fukutani, A., Sawatsky, A., Leonard, T., Herzog, W. Tags: RESEARCH ARTICLE Source Type: research

Overexpression of PGE2 synthase by in vivo transient expression enhances immunocompetency along with fitness cost in a lepidopteran insect [RESEARCH ARTICLE]
This study used in vivo transient expression (IVTE) technique to induce overexpression and assessed subsequent physiological alteration in S. exigua. Se-PGES2 was cloned into a eukaryotic expression vector and transfected to Sf9 cells to monitor its heterologous expression. The Sf9 cells expressed the recombinant Se-PGES2 (rSe-PGES2) at an expected size (~47 kDa), which was localized in cytoplasm. The recombinant expression vector was then used to transfect larvae of S. exigua. Hemocytes collected from the larvae treated with IVTE expressed rSe-PGES2 gene for at least 48 h. The larvae treated with IVTE exhibited an enhance...
Source: Journal of Experimental Biology - July 5, 2019 Category: Biology Authors: Ahmed, S., Hasan, M. A., Kim, Y. Tags: RESEARCH ARTICLE Source Type: research

Upstroke-based acceleration and head stabilization are the norm for the wing-propelled swimming of alcid seabirds [RESEARCH ARTICLE]
Anthony B. Lapsansky and Bret W. Tobalske Alcids, a family of seabirds including murres, guillemots and puffins, exhibit the greatest mass-specific dive depths and durations of any birds or mammals. These impressive diving capabilities have motivated numerous studies on the biomechanics of alcid swimming and diving, with one objective being to compare stroke–acceleration patterns of swimming alcids with those of penguins, where upstroke and downstroke are used for horizontal acceleration. Studies of free-ranging, descending alcids have found that alcids accelerate in the direction of travel during both their upstrok...
Source: Journal of Experimental Biology - July 2, 2019 Category: Biology Authors: Lapsansky, A. B., Tobalske, B. W. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

Understanding diversity in oxidative status and oxidative stress: the opportunities and challenges ahead [COMMENTARY]
David Costantini Oxidative stress may be of profound biological relevance. In this Commentary, I discuss some key issues faced by the emerging field of oxidative stress ecology, and seek to provide interpretations and solutions. First, I show that the way in which we define oxidative stress has far-reaching implications for the interpretation of results, and that we need to distinguish between (1) a biochemical definition in terms of the molecular outcomes of oxidative stress (e.g. generation of oxidative damage) and (2) a biological definition in terms of the fitness consequences for the organism (e.g. effects on fertili...
Source: Journal of Experimental Biology - July 2, 2019 Category: Biology Authors: Costantini, D. Tags: COMMENTARY Source Type: research

Evidence that dopamine is involved in neuroendocrine regulation, gill intracellular signaling pathways and ion regulation in Litopenaeus vannamei [RESEARCH ARTICLE]
Lingjun Si, Luqing Pan, Xin Zhang, Hongdan Wang, and Cun Wei The transport of ions and ammonia in the gills may be regulated by neuroendocrine factors, in order to explore the regulation mechanism of dopamine (DA), hemolymph neuroendocrine hormones, gill intracellular signaling pathways, ion and ammonia transporters, as well as hemolymph osmolality and ammonia concentration were investigated in Litopenaeus vannamei after 10–7 and 10–6 mol shrimp–1 DA injection. The data displayed a significant increase in crustacean hyperglycemic hormone (CHH) concentration at 1-12 h and a transient significant decrease i...
Source: Journal of Experimental Biology - July 2, 2019 Category: Biology Authors: Si, L., Pan, L., Zhang, X., Wang, H., Wei, C. Tags: RESEARCH ARTICLE Source Type: research

Ground reaction forces intersect above the center of mass even when walking down visible and camouflaged curbs [RESEARCH ARTICLE]
In this study, eleven volunteers stepped down off a visible (0, 10, and 20 cm) and a camouflaged (0 or 10 cm) curb while walking at two different speeds (1.2±0.1 m s–1 and 1.7±0.1 m s–1). The results showed that in all conditions the GRF pointed predominantly above the COM. Vectors directed from the center of pressure (COP) to the intersection point (IP) closely fitted the measured GRF direction not only in visible conditions (R2>97.5%), but also in camouflaged curb negotiation (R2>89.8%). Additional analysis of variables included in the calculation of the IP location showed considerable dif...
Source: Journal of Experimental Biology - July 2, 2019 Category: Biology Authors: Vielemeyer, J., Griessbach, E., Müller, R. Tags: RESEARCH ARTICLE Source Type: research

Diel cycling hypoxia enhances hypoxia-tolerance in rainbow trout (Oncorhynchus mykiss): evidence of physiological and metabolic plasticity [RESEARCH ARTICLE]
Kenneth J. Williams, Alicia A. Cassidy, Christine E. Verhille, Simon G. Lamarre, and Tyson J. MacCormack Many fish naturally encounter a daily cycle of hypoxia but it is unclear whether this exposure hardens hypoxia-intolerant fish to future hypoxia or leads to accumulated stress and death. Rainbow trout (Oncorhynchus mykiss) is a putatively hypoxia-sensitive species found in rivers and estuaries that may routinely experience hypoxic events. Trout were exposed to 1 of 4 135h treatments in a swim-tunnel respirometer: 1) air-saturated control (20.7 kPa PO2); 2) diel cycling O2 (20.7-4.2 kPa over 24h); 3) acute hypoxia (130h ...
Source: Journal of Experimental Biology - July 2, 2019 Category: Biology Authors: Williams, K. J., Cassidy, A. A., Verhille, C. E., Lamarre, S. G., MacCormack, T. J. Tags: RESEARCH ARTICLE Source Type: research

Light avoidance by non-ocular photosensing system in the terrestrial slug Limax valentianus [RESEARCH ARTICLE]
Haruka Nishiyama, Akane Nagata, Yuko Matsuo, and Ryota Matsuo Although the eye is the best studied photoreceptive organ in animals, the presence of non-ocular photosensing systems has been reported in numerous animal species. However, most of the roles non-ocular photosensory systems play remain elusive. We found that the terrestrial slug Limax valentianus avoids light and escape into dark areas even if it is blinded by the removal of the bilateral superior tentacle. The escape behaviour was more evident for the short-wavelength light. Illumination with blue but not red light, to the head elicited avoidance behaviour in th...
Source: Journal of Experimental Biology - July 2, 2019 Category: Biology Authors: Nishiyama, H., Nagata, A., Matsuo, Y., Matsuo, R. Tags: RESEARCH ARTICLE Source Type: research

Section-specific H+ flux in renal tubules of fasted and fed goldfish [RESEARCH ARTICLE]
Sandra Fehsenfeld, Dennis Kolosov, Chris M. Wood, and Michael J. O'Donnell A recent study demonstrated that in response to a feeding-induced metabolic acidosis, goldfish (Carassius auratus) adjust epithelial protein and/or mRNA expression in their kidney tubules for multiple transporters known to be relevant for acid–base regulation. These include Na+/H+ exchanger (NHE), V-type H+-ATPase (V-ATPase), cytoplasmic carbonic anhydrase, HCO3– transporters and Rhesus proteins. Consequently, renal acid output in the form of protons and NH4+ increases. However, little is known about the mechanistic details of renal aci...
Source: Journal of Experimental Biology - July 1, 2019 Category: Biology Authors: Fehsenfeld, S., Kolosov, D., Wood, C. M., O'Donnell, M. J. Tags: RESEARCH ARTICLE Source Type: research

Deep breathing in tired trout [OUTSIDE JEB]
Andy Turko (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - July 1, 2019 Category: Biology Authors: Turko, A. Tags: OUTSIDE JEB Source Type: research

A soaring success: repeated evolution of island flightlessness [OUTSIDE JEB]
Ilan Ruhr (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - July 1, 2019 Category: Biology Authors: Ruhr, I. Tags: OUTSIDE JEB Source Type: research

Pesticides put the bumble back into bumblebees [OUTSIDE JEB]
Alex Evans (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - July 1, 2019 Category: Biology Authors: Evans, A. Tags: OUTSIDE JEB Source Type: research

Sit tight: nest temperature affects infection resistance of chicks [OUTSIDE JEB]
Julia Nowack (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - July 1, 2019 Category: Biology Authors: Nowack, J. Tags: OUTSIDE JEB Source Type: research

Electrophysiology and transcriptomics reveal two photoreceptor classes and complex visual integration in Hirudo verbana [RESEARCH ARTICLE]
Annette Stowasser, Aaron Stahl, Joshua B. Benoit, and Daniel A. Wagenaar Among animals with visual processing mechanisms, the leech Hirudo verbana is a rare example in which all neurons can be identified. However, little is known about its visual system, which is composed of several pigmented head eyes and photosensitive non-pigmented sensilla that are distributed across its entire body. Although several interneurons are known to respond to visual stimuli, their response properties are poorly understood. Among these, the S cell system is especially intriguing: It is multimodal, spans the entire body of the leech, and is th...
Source: Journal of Experimental Biology - July 1, 2019 Category: Biology Authors: Stowasser, A., Stahl, A., Benoit, J. B., Wagenaar, D. A. Tags: RESEARCH ARTICLE Source Type: research

What goes up must come down - biomechanical impact analysis of falling locusts [RESEARCH ARTICLE]
In this study we used high-speed recordings to investigate the falling and in particular impact behavior of Schistocerca gregaria locusts, a common model organism for studies on the biomechanics of jumping. Detailed impact analyses of free-falling locusts show that most insects typically crashed onto the substrate. Although free falling locusts tended to spread their legs, they mostly fell onto head and thorax first. The presence of wings did not significantly reduce impact speed, however affected the orientation of the body at impact and significantly reduced the time to recover. Our results also show that alive warm locu...
Source: Journal of Experimental Biology - July 1, 2019 Category: Biology Authors: Reichel, S. V., Labisch, S., Dirks, J.-H. Tags: RESEARCH ARTICLE Source Type: research

What determines the basal rate of metabolism? [RESEARCH ARTICLE]
Brian K. McNab The basal rate of metabolism (BMR) is the most reported estimate of energy expenditure in endotherms. Its principal determinant is body mass, but it also correlates with a variety of behavioral not determine basal rate, they are byproducts of the mechanisms that are its determinate. In mammals, mass-independent basal rate increases with muscle mass when it is>40% of body mass. Then basal rates in mammals are≥100% of the values expected from mass. Mammals with muscle masses
Source: Journal of Experimental Biology - July 1, 2019 Category: Biology Authors: McNab, B. K. Tags: RESEARCH ARTICLE Source Type: research

SERCA boosted in chilly chicks flight muscle for warmth [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - June 28, 2019 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Influence of stretch magnitude on the stretch-shortening cycle in skinned muscle fibres [RESEARCH ARTICLE]
Atsuki Fukutani and Walter Herzog The mechanical work attained during muscle fibre shortening is increased by prior stretching. Recently, we suggested that residual force enhancement (RFE) may contribute to this enhanced work. RFE can be changed reliably by changing the stretch magnitude. Therefore, the purpose of this study was to examine the effect of stretch magnitude, and by association RFE, on the mechanics of the stretch–shortening cycle (SSC) in skinned skeletal muscle fibres. Three tests were performed using skinned rabbit soleus fibres (N=18). The first test was a pure shortening contraction in which fibres...
Source: Journal of Experimental Biology - June 28, 2019 Category: Biology Authors: Fukutani, A., Herzog, W. Tags: RESEARCH ARTICLE Source Type: research

Sarcoplasmic reticulum Ca2+-ATPase (SERCA) activity during the transition to endothermy in an altricial bird [RESEARCH ARTICLE]
Edwin R. Price, Tushar S. Sirsat, Sarah K. G. Sirsat, and Edward M. Dzialowski Sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) is a transmembrane pump critical to muscle calcium cycling during contraction, and SERCA has also been proposed as the basis for a non-shivering thermogenesis mechanism in birds. Despite its potential importance to both shivering and non-shivering thermogenesis, the activity of this transporter has rarely been studied in altricial birds, and never during the developmental transition from ectothermy to endothermy. Here, we describe SERCA activity in the pectoralis muscle and heart ventricle of red...
Source: Journal of Experimental Biology - June 28, 2019 Category: Biology Authors: Price, E. R., Sirsat, T. S., Sirsat, S. K. G., Dzialowski, E. M. Tags: RESEARCH ARTICLE Source Type: research

Chemically induced plasticity in early life history of Palaemon argentinus: are chemical alarm cues conserved within palaemonid shrimps? [RESEARCH ARTICLE]
Romina B. Ituarte, Maria G. Vazquez, and Claudia C. Bas Most aquatic animals use infochemicals from both conspecifics and heterospecifics to assess local predation risks and enhance predator detection. Released substances from injured conspecifics and other species (chemical alarm cues) are reliable cues to indicate an imminent danger in a specific habitat and often mediate the development of inducible defenses. Amphibian and fish embryos have been shown to acquire this information while at the embryonic stage of development, in relation to the developing nervous system and sensory development. With the exception of Daphn...
Source: Journal of Experimental Biology - June 28, 2019 Category: Biology Authors: Ituarte, R. B., Vazquez, M. G., Bas, C. C. Tags: RESEARCH ARTICLE Source Type: research

Ocean acidification affects calcareous tube growth in adults and reared offspring of serpulid polychaetes [RESEARCH ARTICLE]
Victoria Diaz-Castaneda, T. Erin Cox, Frederic Gazeau, Susan Fitzer, Jeremy Delille, Samir Alliouane, and Jean-Pierre Gattuso The energetically costly transition from free-swimming larvae to a benthic life stage and maintenance of a calcareous structure can make calcifying marine invertebrates vulnerable to ocean acidification. The first goal of this study was to evaluate the impact of ocean acidification on calcified tube growth for two Serpulidae polychaete worms. Spirorbis sp. and Spirobranchus triqueter were collected at 11 m depth from the northwest Mediterranean Sea and maintained for 30 and 90 days at thr...
Source: Journal of Experimental Biology - June 28, 2019 Category: Biology Authors: Diaz-Castaneda, V., Cox, T. E., Gazeau, F., Fitzer, S., Delille, J., Alliouane, S., Gattuso, J.-P. Tags: Ecophysiology: responses to environmental stressors and change RESEARCH ARTICLE Source Type: research

Assessment of fatigue-related biochemical alterations in a rat swimming model under hypoxia [RESEARCH ARTICLE]
Fabo Shan, Tao Yang, Junxia Li, and Qing-Yuan Huang It is well known that exercise-induced fatigue is exacerbated following hypoxia exposure and may arise from central and/or peripheral mechanisms. To assess the relative contribution of peripheral and central factors to exercise-induced fatigue under hypoxia, a rat model of fatigue by a bout of exhaustive swimming was established and fatigue-related biochemical changes in normoxic and severe hypoxic conditions were compared. Rats were randomly divided into four groups, normoxia resting (NR), exhaustive swimming (NE), hypoxia resting (HR) and exhaustive swimming (HE) groups...
Source: Journal of Experimental Biology - June 28, 2019 Category: Biology Authors: Shan, F., Yang, T., Li, J., Huang, Q.-Y. Tags: RESEARCH ARTICLE Source Type: research

Locomotor patterns change over time when exposed to an uneven surface [RESEARCH ARTICLE]
Jenny A. Kent, Joel H. Sommerfeld, Mukul Mukherjee, Kota Z. Takahashi, and Nicholas Stergiou During walking, uneven surfaces impose new demands for controlling balance and forward progression at each step. It is unknown the extent to which walking may be refined given a level of stride-to-stride unpredictability at distal level. Here, we explored the effects of an uneven terrain surface on whole-body locomotor dynamics on immediate exposure and after a familiarization period.Eleven young, unimpaired adults walked for 12 minutes on flat and uneven terrain treadmills. The whole-body center of mass excursion range (COMEXC) an...
Source: Journal of Experimental Biology - June 28, 2019 Category: Biology Authors: Kent, J. A., Sommerfeld, J. H., Mukherjee, M., Takahashi, K. Z., Stergiou, N. Tags: RESEARCH ARTICLE Source Type: research

Histone deacetylase activity is required for Botrylloides leachii whole body regeneration [RESEARCH ARTICLE]
Lisa Zondag, Rebecca Clarke, and Megan J. Wilson The colonial tunicate Botrylloides leachii is exceptional at regenerating from a piece of vascular tunic after loss of all adults from the colony. Previous transcriptome analyses indicate a brief period of healing before regeneration of a new adult (zooid) in as little as 8-10 days. However, there is little understanding of how the resulting changes to gene expression, required to drive regeneration, are initiated and how the overall process is regulated. Rapid changes to transcription often occur in response to chromatin changes, mediated by histone modifications such as hi...
Source: Journal of Experimental Biology - June 28, 2019 Category: Biology Authors: Zondag, L., Clarke, R., Wilson, M. J. Tags: RESEARCH ARTICLE Source Type: research

Strain transformation: Enhancement of invertebrate memory in a new rearing environment [RESEARCH ARTICLE]
Cailin M. Rothwell and Ken Lukowiak Memory formation is influenced by a variety of factors, including the environmental conditions in which an organism is reared. Here, we studied the memory-forming ability of the lab-bred B-strain of Lymnaea following a change in their rearing environment from Brock University to the University of Calgary. We have previously demonstrated that this move enhances memory-forming ability and here we studied the magnitude of this phenotypic change. Once reared to adulthood at the University of Calgary, the B-strain animals were first tested to determine how many training sessions were required...
Source: Journal of Experimental Biology - June 28, 2019 Category: Biology Authors: Rothwell, C. M., Lukowiak, K. Tags: RESEARCH ARTICLE Source Type: research

CB1 and CB2 receptors play differential roles in early zebrafish locomotor development [RESEARCH ARTICLE]
In this study we investigated the roles of the eCB system in zebrafish development by pharmacologically inhibiting the CB1R and CB2Rs (with AM251 and AM630 respectively) in either the first or second day of development. We examined the morphology of motor neurons and we determined neuromuscular outputs by quantifying the amount of swimming in 5 dpf larva. Blocking CB2R during the first day of development resulted in gross morphological deficits and reductions in heart rate that were greater than that following treatment with the CB1R blocker AM251. Blocking CB1Rs from 0 to 24 hpf resulted in an increase in the number of se...
Source: Journal of Experimental Biology - June 28, 2019 Category: Biology Authors: Sufian, M. S., Amin, M. R., Kanyo, R., Allison, W. T., Ali, D. W. Tags: RESEARCH ARTICLE Source Type: research

The photon menace: kleptoplast protection in the photosynthetic sea slug Elysia timida [SHORT COMMUNICATION]
Paulo Cartaxana, Luca Morelli, Bruno Jesus, Goncalo Calado, Ricardo Calado, and Sonia Cruz Absorption of excessive light by photosymbiotic organisms leads to the production of reactive oxygen species that can damage both symbiont and host. This is highly relevant in sacoglossan sea slugs that host functional chloroplasts ‘stolen’ from their algal foods (kleptoplasts), because of limited repair capacities resulting from the absence of algal nuclear genes. Here, we experimentally demonstrate (i) a host-mediated photoprotection mechanism in the photosynthetic sea slug Elysia timida, characterized by the closure o...
Source: Journal of Experimental Biology - June 27, 2019 Category: Biology Authors: Cartaxana, P., Morelli, L., Jesus, B., Calado, G., Calado, R., Cruz, S. Tags: SHORT COMMUNICATION Source Type: research

Comprehensive analysis of genes contributing to euryhalinity in the bull shark, Carcharhinus leucas; Na+-Cl- co-transporter is one of the key renal factors upregulated in acclimation to low-salinity environment [RESEARCH ARTICLE]
Itaru Imaseki, Midori Wakabayashi, Yuichiro Hara, Taro Watanabe, Souichirou Takabe, Keigo Kakumura, Yuki Honda, Keiichi Ueda, Kiyomi Murakumo, Rui Matsumoto, Yosuke Matsumoto, Masaru Nakamura, Wataru Takagi, Shigehiro Kuraku, and Susumu Hyodo Most cartilaginous fishes live principally in seawater (SW) environments, but a limited number of species including the bull shark, Carcharhinus leucas, inhabit both SW and freshwater (FW) environments during their life cycle. Euryhaline elasmobranchs maintain high internal urea and ion levels even in FW environments, but little is known about the osmoregulatory mechanisms that enabl...
Source: Journal of Experimental Biology - June 27, 2019 Category: Biology Authors: Imaseki, I., Wakabayashi, M., Hara, Y., Watanabe, T., Takabe, S., Kakumura, K., Honda, Y., Ueda, K., Murakumo, K., Matsumoto, R., Matsumoto, Y., Nakamura, M., Takagi, W., Kuraku, S., Hyodo, S. Tags: RESEARCH ARTICLE Source Type: research

Differences in ocular media transmittance in classical frog and toad model species and its impact on visual sensitivity [SHORT COMMUNICATION]
Carola A. M. Yovanovich, Taran Grant, and Almut Kelber The transmittance properties of the cornea, lens and humours of vertebrates determine how much light across the visible spectrum reaches the retina, influencing sensitivity to visual stimuli. Amphibians are the only vertebrate class in which the light transmittance of these ocular media has not been thoroughly characterised, preventing large-scale comparative studies and precise quantification of visual stimuli in physiological and behavioural experiments. We measured the ocular media transmittance in some commonly used species of amphibians (the bufonids Bufo bufo an...
Source: Journal of Experimental Biology - June 25, 2019 Category: Biology Authors: Yovanovich, C. A. M., Grant, T., Kelber, A. Tags: SHORT COMMUNICATION Source Type: research