Prenatal independent and combined effects of yolk vitamin E and corticosterone on embryo growth and oxidative status in the yellow-legged gull [RESEARCH ARTICLE]
Marco Parolini, Cristina Daniela Possenti, Simona Secomandi, Silvia Carboni, Manuela Caprioli, Diego Rubolini, Andrea Romano, and Nicola Saino Variation in the concentration of antioxidants and hormones of maternal origin in the eggs of birds can have profound influences on offspring phenotype both pre- and post-natally. Egg maternal substances, however, can have interacting effects, but experimental studies of the consequences of the combined variation in the egg concentration of such molecules are extremely rare, particularly as far as prenatal stages are considered. We manipulated the yolk concentrations of vitamin E an...
Source: Journal of Experimental Biology - May 1, 2019 Category: Biology Authors: Parolini, M., Possenti, C. D., Secomandi, S., Carboni, S., Caprioli, M., Rubolini, D., Romano, A., Saino, N. Tags: RESEARCH ARTICLE Source Type: research

Voltages and resistances of the anterior Malpighian tubule of Drosophila melanogaster [RESEARCH ARTICLE]
Klaus W. Beyenbach The small size of Malpighian tubules in the fruit fly Drosophila melanogaster has discouraged measurements of the transepithelial electrical resistance. The present study introduces two methods for measuring the transepithelial resistance in isolated Drosophila Malpighian tubules using conventional microelectrodes and PClamp hardware and software. The first method uses three microelectrodes to measure the specific transepithelial resistance normalized to tubule length or luminal surface area for comparison with resistances of other epithelia. The second method uses only two microelectrodes to measure the...
Source: Journal of Experimental Biology - May 1, 2019 Category: Biology Authors: Beyenbach, K. W. Tags: RESEARCH ARTICLE Source Type: research

Changes in vitellogenin expression caused by nematodal and fungal infections in insects [RESEARCH ARTICLE]
This study examined the expression and role of vitellogenin (Vg) in the body of the firebug Pyrrhocoris apterus (Heteroptera, Insecta) during the infection elicited by two entomopathogenic organisms, the nematode Steinernema carpocapsae and the fungus Isaria fumosorosea. Infection by S. carpocapsae significantly up-regulated Vg mRNA expression in the male body. The corresponding increase in Vg protein expression was also confirmed by electrophoretic and immunoblotting analyses. Remarkably, in females, the tendency was opposite. Nematodal infection significantly reduced both Vg mRNA and Vg protein expression levels in fat b...
Source: Journal of Experimental Biology - May 1, 2019 Category: Biology Authors: Kodrik, D., Ibrahim, E., Gautam, U. K., Frydrychova, R. C., Bednarova, A., Kristufek, V., Jedlicka, P. Tags: RESEARCH ARTICLE Source Type: research

Selection for longer limbs in mice increases bone stiffness and brittleness, but does not alter bending strength [RESEARCH ARTICLE]
Miranda N. Cosman, Hayley M. Britz, and Campbell Rolian The ability of a bone to withstand loads depends on its structural and material properties. These tend to differ among species with different modes of locomotion, reflecting their unique loading patterns. The evolution of derived limb morphologies, such as the long limbs associated with jumping, may compromise overall bone strength. We evaluated bone mechanical properties in the Longshanks mouse, which was selectively bred for increased tibia length relative to body mass. We combined analyses of 3D shape and cross-sectional geometry of the tibia, with mechanical testi...
Source: Journal of Experimental Biology - May 1, 2019 Category: Biology Authors: Cosman, M. N., Britz, H. M., Rolian, C. Tags: RESEARCH ARTICLE Source Type: research

Hikers trade speed and efficiency for stability [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - April 30, 2019 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Cost of transport is a repeatable trait but is not determined by mitochondrial efficiency in zebrafish (Danio rerio) [RESEARCH ARTICLE]
Miki Jahn and Frank Seebacher The energy used to move a given distance (cost of transport; CoT) varies significantly between individuals of the same species. A lower CoT allows animals to allocate more of their energy budget to growth and reproduction. A higher CoT may cause animals to adjust their movement across different environmental gradients to reduce energy allocated to movement. The aim of this project was to determine whether CoT is a repeatable trait within individuals, and to determine its physiological causes and ecological consequences. We found that CoT is a repeatable trait in zebrafish (Danio rerio). We re...
Source: Journal of Experimental Biology - April 30, 2019 Category: Biology Authors: Jahn, M., Seebacher, F. Tags: RESEARCH ARTICLE Source Type: research

Joint angular excursions during cyclical behaviors differ between tetrapod feeding and locomotor systems [RESEARCH ARTICLE]
In this study, we compare average joint angular excursions during cyclic behaviors – chewing, walking and running – in a phylogenetic context to explore differences in the optimality criteria of these two systems. Across 111 tetrapod species, average limb-joint angular excursions during cyclic locomotion are greater and more evolutionarily labile than those of the jaw joint during cyclic chewing. We argue that these findings reflect fundamental functional dichotomies between tetrapod locomotor and feeding systems. Tetrapod chewing systems are optimized for precise application of force over a narrower, more cont...
Source: Journal of Experimental Biology - April 30, 2019 Category: Biology Authors: Granatosky, M. C., McElroy, E. J., Laird, M. F., Iriarte-Diaz, J., Reilly, S. M., Taylor, A. B., Ross, C. F. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

How does the water springtail optically locate suitable habitats? Spectral sensitivity of phototaxis and polarotaxis in Podura aquatica [RESEARCH ARTICLE]
We present our experiments and discuss the possible ecological significance of our findings. (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - April 30, 2019 Category: Biology Authors: Egri, A., Kriska, G. Tags: RESEARCH ARTICLE Source Type: research

Severe thermoregulatory deficiencies in mice with a deletion in the titin gene TTN [RESEARCH ARTICLE]
Carissa A. Miyano, Santiago F. Orezzoli, C. Loren Buck, and Kiisa C. Nishikawa Muscular dystrophy with myositis (mdm) mice carry a deletion in the N2A region of the gene for the muscle protein titin (TTN), shiver at low frequency, fail to maintain body temperatures (Tb) at ambient temperatures (Ta)
Source: Journal of Experimental Biology - April 30, 2019 Category: Biology Authors: Miyano, C. A., Orezzoli, S. F., Buck, C. L., Nishikawa, K. C. Tags: RESEARCH ARTICLE Source Type: research

Respiratory sinus arrhythmia is a major component of heart rate variability in undisturbed, remotely monitored rattlesnakes, Crotalus durissus [RESEARCH ARTICLE]
Pollyana V. W. Sanches, Edwin W. Taylor, Livia M. Duran, Andre L. Cruz, Daniel P. M. Dias, and Cleo A. C. Leite ECG recordings were obtained using an implanted telemetry device from the South American rattlesnake, Crotalus durissus, held under stable conditions without restraining cables or interaction with researchers. Mean heart rate (fH) recovered rapidly (
Source: Journal of Experimental Biology - April 30, 2019 Category: Biology Authors: Sanches, P. V. W., Taylor, E. W., Duran, L. M., Cruz, A. L., Dias, D. P. M., Leite, C. A. C. Tags: RESEARCH ARTICLE Source Type: research

Is conservation of center of mass mechanics a priority in human walking? Insights from leg-length asymmetry experiments [RESEARCH ARTICLE]
Kirsty A. McDonald, Daniel Devaprakash, and Jonas Rubenson Center of mass (COM) control has been proposed to serve economy- and stability-related locomotor task objectives. However, given the lack of evidence supporting direct sensing and/or regulation of the COM, it remains unclear whether COM mechanics are prioritized in the control scheme of walking. We posit that peripheral musculoskeletal structures, e.g. muscle, are more realistic control targets than the COM, given their abundance of sensorimotor receptors and ability to influence whole-body energetics. As a first test of this hypothesis, we examined whether conser...
Source: Journal of Experimental Biology - April 30, 2019 Category: Biology Authors: McDonald, K. A., Devaprakash, D., Rubenson, J. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

The vertebrate story lies in the fossil of a slimy fish [OUTSIDE JEB]
Oana Birceanu (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - April 30, 2019 Category: Biology Authors: Birceanu, O. Tags: OUTSIDE JEB Source Type: research

Are fish self-aware? [OUTSIDE JEB]
Erin McCallum (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - April 30, 2019 Category: Biology Authors: McCallum, E. Tags: OUTSIDE JEB Source Type: research

It's a small world on a hot leaf [OUTSIDE JEB]
James M. Turner (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - April 30, 2019 Category: Biology Authors: Turner, J. M. Tags: OUTSIDE JEB Source Type: research

Singing mice take turns talking [OUTSIDE JEB]
Daniel M. Vahaba (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - April 30, 2019 Category: Biology Authors: Vahaba, D. M. Tags: OUTSIDE JEB Source Type: research

Genes of the world's coolest fish [OUTSIDE JEB]
Brittney G. Borowiec (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - April 30, 2019 Category: Biology Authors: Borowiec, B. G. Tags: OUTSIDE JEB Source Type: research

Preferred walking speed on rough terrain: is it all about energetics? [RESEARCH ARTICLE]
Koren Gast, Rodger Kram, and Raziel Riemer Humans have evolved the ability to walk very efficiently. Further, humans prefer to walk at speeds that approximately minimize their metabolic energy expenditure per unit distance (i.e. gross cost of transport, COT). This has been found in a variety of population groups and other species. However, these studies were mostly performed on smooth, level ground or on treadmills. We hypothesized that the objective function for walking is more complex than only minimizing the COT. To test this idea, we compared the preferred speeds and the relationships between COT and speed for people ...
Source: Journal of Experimental Biology - April 30, 2019 Category: Biology Authors: Gast, K., Kram, R., Riemer, R. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

Fish fin physique factor in food preferences [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - April 26, 2019 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Respiratory gas levels interact to control ventilatory motor patterns in isolated locust ganglia [RESEARCH ARTICLE]
Stav Talal, Amir Ayali, and Eran Gefen Large insects actively ventilate their tracheal system even at rest, using abdominal pumping movements, which are controlled by a central pattern generator (CPG) in the thoracic ganglia. We studied the effects of respiratory gases on the ventilatory rhythm by isolating the thoracic ganglia and perfusing its main tracheae with various respiratory gas mixtures. Fictive ventilation activity was recorded from motor nerves controlling spiracular and abdominal ventilatory muscles. Both hypoxia and hypercapnia increased the ventilation rate, with the latter being much more potent. Sub-thres...
Source: Journal of Experimental Biology - April 26, 2019 Category: Biology Authors: Talal, S., Ayali, A., Gefen, E. Tags: RESEARCH ARTICLE Source Type: research

Parabronchial remodeling in chicks in response to embryonic hypoxia [RESEARCH ARTICLE]
Lara do Amaral-Silva, Markus Lambertz, Fernando Jose Zara, Wilfried Klein, Luciane Helena Gargaglioni, and Kenia Cardoso Bicego The embryonic development of parabronchi occurs mainly during the second half of incubation in precocious birds, which makes this phase sensitive to possible morphological modifications induced by O2 supply limitation. Thus, we hypothesized that hypoxia during the embryonic phase of parabronchial development induces morphological changes that remain after hatching. To test this hypothesis, chicken embryos were incubated entirely (21 days) under normoxia or partially under hypoxia (15% O2 during da...
Source: Journal of Experimental Biology - April 26, 2019 Category: Biology Authors: Amaral-Silva, L. d., Lambertz, M., Zara, F. J., Klein, W., Gargaglioni, L. H., Bicego, K. C. Tags: RESEARCH ARTICLE Source Type: research

The gastric sieve of penaeid shrimp species is a sub-micron nutrient filter [RESEARCH ARTICLE]
Werawich Pattarayingsakul, Arnon Pudgerd, Natthinee Munkongwongsiri, Rapeepun Vanichviriyakit, Thawatchai Chaijarasphong, Siripong Thitamadee, and Thanapong Kruangkum Unlike vertebrates, the penaeid shrimp stomach is of ectodermic origin and is thus covered by a cuticle that is sloughed upon molting. It is composed of two chambers, here called the anterior and posterior stomach chambers, ASC and PSC respectively. The PSC contains a filtration structure variously called a pyloric filter, filter press, gastric filter or gastric sieve (GS) and the latter will be used here. The GS resembles an elongated, inverted-V, dome-like,...
Source: Journal of Experimental Biology - April 26, 2019 Category: Biology Authors: Pattarayingsakul, W., Pudgerd, A., Munkongwongsiri, N., Vanichviriyakit, R., Chaijarasphong, T., Thitamadee, S., Kruangkum, T. Tags: RESEARCH ARTICLE Source Type: research

Responses of compass neurons in the locust brain to visual motion and leg motor activity [RESEARCH ARTICLE]
Ronny Rosner, Uta Pegel, and Uwe Homberg The central complex, a group of midline neuropils in the insect brain, plays a key role in spatial orientation and navigation. Work in locusts, crickets, dung beetles, bees and butterflies suggests that it harbors a network of neurons which determines the orientation of the insect relative to the pattern of polarized light in the blue sky. In locusts, these ‘compass cells’ also respond to simulated approaching objects. Here, we investigated in the locust Schistocerca gregaria whether compass cells change their activity when the animal experiences large-field visual moti...
Source: Journal of Experimental Biology - April 25, 2019 Category: Biology Authors: Rosner, R., Pegel, U., Homberg, U. Tags: Neuroethology RESEARCH ARTICLE Source Type: research

Loss of angiotensin-converting enzyme-related (ACER) peptidase disrupts behavioural and metabolic responses to diet in Drosophila melanogaster [RESEARCH ARTICLE]
Zoe Glover, Matthew D. Hodges, Nikolett Dravecz, Jack Cameron, Helen Askwith, Alan Shirras, and Susan J. Broughton Drosophila Acer (Angiotensin-converting enzyme-related) encodes a member of the angiotensin-converting enzyme (ACE) family of metallopeptidases that in mammals play roles in the endocrine regulation of blood homeostasis. ACE is also expressed in adipose tissue, where it is thought to play a role in metabolic regulation. Drosophila ACER is expressed in the adult fat body of the head and abdomen and is secreted into the haemolymph. Acer null mutants have previously been found to have reduced night-time sleep an...
Source: Journal of Experimental Biology - April 25, 2019 Category: Biology Authors: Glover, Z., Hodges, M. D., Dravecz, N., Cameron, J., Askwith, H., Shirras, A., Broughton, S. J. Tags: RESEARCH ARTICLE Source Type: research

Diving loggerhead turtles don't drop heart rate to conserve oxygen [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - April 24, 2019 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Activity, not submergence, explains diving heart rates of captive loggerhead sea turtles [RESEARCH ARTICLE]
This study examined cardiovascular responses in loggerhead sea turtles, which have even fewer adaptations to diving than other marine turtles, but can dive for extended durations. Heart rates (fH) of eight undisturbed loggerhead turtles in shallow tanks were measured using self-contained ECG data loggers under five conditions: spontaneous dives, resting motionless on the tank bottom, resting in shallow water with their head out of water, feeding on squid, and swimming at the surface between dives. There was no significant difference between resting fH while resting on the bottom of the tank, diving or resting in shallow wa...
Source: Journal of Experimental Biology - April 24, 2019 Category: Biology Authors: Williams, C. L., Sato, K., Ponganis, P. J. Tags: RESEARCH ARTICLE Source Type: research

Enhanced transport of nutrients powered by microscale flows of the self-spinning dinoflagellate Symbiodinium sp. [RESEARCH ARTICLE]
Zheng Zhu and Quan-Xing Liu The metabolism of a living organism (e.g. bacteria, algae, zooplankton) requires a continuous uptake of nutrients from the surrounding environment. However, within local spatial scales, nutrients are quickly used up under dense concentrations of organisms. Here, we report that self-spinning dinoflagellates Symbiodinium sp. (clade E) generate a microscale flow that mitigates competition and enhances the uptake of nutrients from the surrounding environment. Our experimental and theoretical results reveal that this incessant active behavior enhances transport by approximately 80-fold when compared...
Source: Journal of Experimental Biology - April 24, 2019 Category: Biology Authors: Zhu, Z., Liu, Q.-X. Tags: RESEARCH ARTICLE Source Type: research

Are there synergistic or antagonistic effects of multiple maternally derived egg components on offspring phenotype? [RESEARCH ARTICLE]
Roxana Torres, Eunice Chin, Rowan Rampton, and Tony D. Williams Eggs are ‘multivariate’ in that they contain multiple maternally derived egg components (e.g. hormones, antibodies, mRNA, antioxidants) which are thought to influence offspring phenotype. However, most studies have focused on single egg components and on short-term effects. Here, we simultaneously manipulated two egg components, maternally derived antibodies (MAb) and yolk testosterone, to assess potential synergistic or antagonistic effects on zebra finch offspring phenotype from hatching to sexual maturity. We found no evidence for short- or lon...
Source: Journal of Experimental Biology - April 24, 2019 Category: Biology Authors: Torres, R., Chin, E., Rampton, R., Williams, T. D. Tags: RESEARCH ARTICLE Source Type: research

Functional morphology of endurance swimming performance and gait transition strategies in balistoid fishes [RESEARCH ARTICLE]
Andrew B. George and Mark W. Westneat Triggerfishes and filefishes (Balistoidea) use balistiform locomotion to power steady swimming with their dorsal and anal fins, and transition to a gait dominated by body and caudal fin (BCF) kinematics at high speeds. Fin and body shapes are predicted to be strong determinants of swimming performance and gait transitions. The goal of this study was to combine morphometrics and critical swimming tests to explore the relationships between fin and body shapes and swimming performance in a phylogenetic context in order to understand the evolution of balistiform swimming. Among 13 species...
Source: Journal of Experimental Biology - April 24, 2019 Category: Biology Authors: George, A. B., Westneat, M. W. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

Predatory posture and performance in a precocious larval fish targeting evasive copepods [SHORT COMMUNICATION]
Mary C. Fashingbauer, Lillian J. Tuttle, H. Eve Robinson, J. Rudi Strickler, Daniel K. Hartline, and Petra H. Lenz Predatory fishes avoid detection by prey through a stealthy approach, followed by a rapid and precise fast-start strike. While many first-feeding fish larvae strike at non-evasive prey using an S-start, the clownfish Amphiprion ocellaris feeds on highly evasive calanoid copepods from a J-shaped position, beginning 1 day post-hatch (dph). We quantified this unique strike posture by observing successful predatory interactions between larval clownfish (1 to 14 dph) and three developmental stages of the calanoid c...
Source: Journal of Experimental Biology - April 24, 2019 Category: Biology Authors: Fashingbauer, M. C., Tuttle, L. J., Robinson, H. E., Strickler, J. R., Hartline, D. K., Lenz, P. H. Tags: SHORT COMMUNICATION Source Type: research

Effects of group size on learning and memory in the honey bee, Apis mellifera [RESEARCH ARTICLE]
Nadejda Tsvetkov, Chelsea N. Cook, and Amro Zayed In animals that experience interactions with conspecifics while young, social interactions appear to be a necessary prerequisite for typical behaviour. Eusocial insects have large colonies where individuals experience a great deal of social interactions with nest mates during all life stages, making them excellent candidates for understanding the effects of social isolation on brain development and behaviour. Here we used the honey bee Apis mellifera to study the effect of social isolation and group size on reward perception and discrimination learning and memory. We confin...
Source: Journal of Experimental Biology - April 24, 2019 Category: Biology Authors: Tsvetkov, N., Cook, C. N., Zayed, A. Tags: RESEARCH ARTICLE Source Type: research

Maternal exercise before and during gestation modifies liver and muscle mitochondria in rat offspring [RESEARCH ARTICLE]
Farida Siti, Herve Dubouchaud, Isabelle Hininger, Charline Quiclet, Guillaume Vial, Anne Galinier, Louis Casteilla, Eric Fontaine, Cecile Batandier, and Karine Couturier It is now well established that the intrauterine life environment is of major importance for health during later life. Endurance training during pregnancy is associated with positive metabolic adjustments and beneficial effects on the balance between pro and antioxidant (redox state) in the offspring. Our hypothesis is that these changes could rely on mitochondrial adaptations in the offspring due to modifications of the fetal environment induced by matern...
Source: Journal of Experimental Biology - April 24, 2019 Category: Biology Authors: Siti, F., Dubouchaud, H., Hininger, I., Quiclet, C., Vial, G., Galinier, A., Casteilla, L., Fontaine, E., Batandier, C., Couturier, K. Tags: RESEARCH ARTICLE Source Type: research

Dim-light vision in jumping spiders (Araneae, Salticidae): identification of prey and rivals [RESEARCH ARTICLE]
Ana M. Cerveira, Robert R. Jackson, and Ximena J. Nelson Jumping spiders (family Salticidae) are known for their intricate vision-based behavior during encounters with prey and conspecific individuals. This is achieved using eyes specialized for discerning fine detail, but there has been minimal research on the capacities that salticids might have for visual performance under low ambient light levels. Here we investigate the capacity of two salticid species, Cyrba algerina from Portugal and C. ocellata from Kenya, to perform two specific visual tasks under low ambient light levels. We used lures made from spiders and midge...
Source: Journal of Experimental Biology - April 24, 2019 Category: Biology Authors: Cerveira, A. M., Jackson, R. R., Nelson, X. J. Tags: RESEARCH ARTICLE Source Type: research

Vision is highly sensitive to oxygen availability in marine invertebrate larvae [RESEARCH ARTICLE]
Lillian R. McCormick, Lisa A. Levin, and Nicholas W. Oesch For many animals, evolution has selected for complex visual systems despite the high energetic demands associated with maintaining eyes and their processing structures. The metabolic demands of visual systems therefore make them highly sensitive to fluctuations in available oxygen. In the marine environment, oxygen changes over daily, seasonal, and inter-annual time scales and there are large gradients of oxygen with depth. Vision is linked to survival in many marine animals, particularly among the crustaceans, cephalopods, and fish, and early life stages of these ...
Source: Journal of Experimental Biology - April 24, 2019 Category: Biology Authors: McCormick, L. R., Levin, L. A., Oesch, N. W. Tags: RESEARCH ARTICLE Source Type: research

Functional characterisation of two {Delta}12-desaturases demonstrates targeted production of linoleic acid as pheromone precursor in Nasonia [RESEARCH ARTICLE]
Florian Semmelmann, Naoki Kabeya, Miriama Malcicka, Astrid Bruckmann, Bastian Broschwitz, Kristina Straub, Rainer Merkl, Oscar Monroig, Reinhard Sterner, Joachim Ruther, and Jacintha Ellers Insect pheromones are often derived from fatty acid metabolism. Fatty acid desaturases, enzymes introducing double bonds into fatty acids, are crucial for the biosynthesis of these chemical signals. 12-desaturases catalyse the biosynthesis of linoleic acid by introducing a second double bond into oleic acid, but have been identified in only few animal species. Here we report the functional characterisation of two 12- desaturases, Nvit_D...
Source: Journal of Experimental Biology - April 24, 2019 Category: Biology Authors: Semmelmann, F., Kabeya, N., Malcicka, M., Bruckmann, A., Broschwitz, B., Straub, K., Merkl, R., Monroig, O., Sterner, R., Ruther, J., Ellers, J. Tags: RESEARCH ARTICLE Source Type: research

Autonomic cardiac regulation facilitates acute heat tolerance in rainbow trout: in situ and in vivo support [RESEARCH ARTICLE]
Matthew J. H. Gilbert, Varsha Rani, Sean M. McKenzie, and Anthony P. Farrell Acute warming in fish increases heart rate (fH) and cardiac output to peak values, after which performance plateaus or declines and arrhythmia may occur. This cardiac response can place a convective limitation on systemic oxygen delivery at high temperatures. To test the hypothesis that autonomic cardiac regulation protects cardiac performance in rainbow trout during acute warming, we investigated adrenergic and cholinergic regulation during the onset and progression of cardiac limitations. We explored the direct effects of adrenergic stimulation ...
Source: Journal of Experimental Biology - April 23, 2019 Category: Biology Authors: Gilbert, M. J. H., Rani, V., McKenzie, S. M., Farrell, A. P. Tags: RESEARCH ARTICLE Source Type: research

Severe thermoregulatory deficiencies in mice with a deletion in the titin gene [RESEARCH ARTICLE]
Carissa A. Miyano, Santiago F. Orezzoli, C. Loren Buck, and Kiisa C. Nishikawa Muscular dystrophy with myositis (mdm) mice carry a deletion in the N2A region of the gene for the muscle protein titin, shiver at low frequency, fail to maintain body temperatures (Tb) at ambient temperatures (Ta)
Source: Journal of Experimental Biology - April 23, 2019 Category: Biology Authors: Miyano, C. A., Orezzoli, S. F., Buck, C. L., Nishikawa, K. C. Tags: RESEARCH ARTICLE Source Type: research

How does the water springtail optically locate proper habitats? Spectral sensitivity of photo- and polarotaxis in Podura aquatica [RESEARCH ARTICLE]
Adam Egri and György Kriska Optical water detection by means of horizontally polarized light is widespread among aquatic insects. This ability of these insects usually works in the UV or blue spectral ranges. Recently it was demonstrated that at least one collembolan species, the water springtail (Podura aquatica) also possess positive polarotaxis to horizontally polarized light. These hexapods are positively phototactic, live on the surface of calm waters and usually accumulate in the intimate vicinity of the riparian vegetation. In laboratory experiments we measured the wavelength dependence of phototaxis and polarotax...
Source: Journal of Experimental Biology - April 23, 2019 Category: Biology Authors: Egri, A., Kriska, G. Tags: RESEARCH ARTICLE Source Type: research

Ammonia-N exposure alters neurohormone levels in the hemolymph and mRNA abundance of neurohormone receptors and associated downstream factors in the gills of Litopenaeus vannamei [RESEARCH ARTICLE]
Lingjun Si, Luqing Pan, Hongdan Wang, and Xin Zhang Effects of ammonia-N (0.05, 2, 10 and 20 mg L–1) on the neuroendocrine regulation of ammonia transport were investigated in Litopenaeus vannamei. The results showed that corticotrophin-releasing hormone, adrenocorticotropic hormone, dopamine, noradrenaline and 5-hydroxytryptamine concentration in all ammonia-N groups increased significantly between 3-12 h. Cortisol increased significantly between 3-24 h. All hormones except crustacean hyperglycemic hormone were reduced to control levels. mRNA abundance of guanylyl cyclase increased significantly during the experimen...
Source: Journal of Experimental Biology - April 23, 2019 Category: Biology Authors: Si, L., Pan, L., Wang, H., Zhang, X. Tags: RESEARCH ARTICLE Source Type: research

A new, practicable and economical cage design for experimental studies on small honey bee colonies [METHODS [amp ] TECHNIQUES]
This study details a practicable, new and economical cage system that effectively houses live honey bee colonies to investigate the impact of physical conditions, biological factors and environmental contaminants on honey bee health. The method has broad application for a range of effect studies concerning honey bee development, physiology, survival and population dynamics because it enables entire colonies to be managed well in captivity, as opposed to individual workers. (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - April 23, 2019 Category: Biology Authors: Sonter, C. A., Rader, R., Wilson, S. C. Tags: METHODS [amp ] TECHNIQUES Source Type: research

Evidence for absence of bilateral transfer of olfactory learned information in Apis dorsata and Apis mellifera [RESEARCH ARTICLE]
Meenakshi Vijaykumar, Sandhya Mogily, Aparna Dutta-Gupta, and Joby Joseph The capacity and condition under which the lateral transfer of olfactory memory is possible in insects is still debated. Here, we present evidence in two species of honeybees, Apis mellifera and Apis dorsata, consistent with the lack of ability to transfer olfactory associative memory in a proboscis extension response (PER) associative conditioning paradigm, where the untrained antenna is blocked by an insulating coat. We show that the olfactory system on each side of the bee can learn and retrieve information independently and the retrieval using t...
Source: Journal of Experimental Biology - April 18, 2019 Category: Biology Authors: Vijaykumar, M., Mogily, S., Dutta-Gupta, A., Joseph, J. Tags: RESEARCH ARTICLE Source Type: research

Snakes partition their body to traverse large steps stably [RESEARCH ARTICLE]
Sean W. Gart, Thomas W. Mitchel, and Chen Li Many snakes live in deserts, forests and river valleys and traverse challenging 3-D terrain such as rocks, felled trees and rubble, with obstacles as large as themselves and variable surface properties. By contrast, apart from branch cantilevering, burrowing, swimming and gliding, laboratory studies of snake locomotion have focused on locomotion on simple flat surfaces. Here, to begin to understand snake locomotion in complex 3-D terrain, we studied how the variable kingsnake, a terrestrial generalist, traversed a large step of variable surface friction and step height (up to 3...
Source: Journal of Experimental Biology - April 18, 2019 Category: Biology Authors: Gart, S. W., Mitchel, T. W., Li, C. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

The metabolic cost of in vivo constant muscle force production at zero net mechanical work [RESEARCH ARTICLE]
Tim J. van der Zee, Koen K. Lemaire, and Arthur J. van Soest The metabolic cost per unit force is generally thought to increase with the mechanical work done by the muscle fibres. It is currently unclear how the metabolic cost of doing alternating positive and negative muscle fibre mechanical work relates to the metabolic cost of doing zero muscle fibre mechanical work at similar muscle force. The current study aimed to investigate this issue by comparing in vivo metabolic power between a dynamic and an isometric near-constant force production task. In both tasks, participants performed periodic movement about the knee jo...
Source: Journal of Experimental Biology - April 17, 2019 Category: Biology Authors: van der Zee, T. J., Lemaire, K. K., van Soest, A. J. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

Resolving coral photoacclimation dynamics through coupled photophysiological and metabolomic profiling [RESEARCH ARTICLE]
Kathryn E. Lohr, Emma F. Camp, Unnikrishnan Kuzhiumparambil, Adrian Lutz, William Leggat, Joshua T. Patterson, and David J. Suggett Corals continuously adjust to short-term variation in light availability on shallow reefs. Long-term light alterations can also occur as a result of natural and anthropogenic stressors, as well as management interventions such as coral transplantation. Although short-term photophysiological responses are relatively well understood in corals, little information is available regarding photoacclimation dynamics over weeks of altered light availability. We coupled photophysiology and metabolomic ...
Source: Journal of Experimental Biology - April 17, 2019 Category: Biology Authors: Lohr, K. E., Camp, E. F., Kuzhiumparambil, U., Lutz, A., Leggat, W., Patterson, J. T., Suggett, D. J. Tags: RESEARCH ARTICLE Source Type: research

Echolocating bats inspect and discriminate landmark features to guide navigation [RESEARCH ARTICLE]
Chao Yu, Jinhong Luo, Melville Wohlgemuth, and Cynthia F. Moss Landmark-guided navigation is a common behavioral strategy for way-finding, yet prior studies have not examined how animals collect sensory information to discriminate landmark features. We investigated this question in animals that rely on active sensing to guide navigation. Four echolocating bats (Eptesicus fuscus) were trained to use an acoustic landmark to find and navigate through a net opening for a food reward. In experimental trials, an object serving as a landmark was placed adjacent to a net opening and an object serving as a distractor was placed ne...
Source: Journal of Experimental Biology - April 17, 2019 Category: Biology Authors: Yu, C., Luo, J., Wohlgemuth, M., Moss, C. F. Tags: RESEARCH ARTICLE Source Type: research

Hypoxia tolerance of giant axon-mediated escape jetting in California market squid (Doryteuthis opalescens) [RESEARCH ARTICLE]
Diana H. Li and William F. Gilly Squids display a wide range of swimming behaviors, including powerful escape jets mediated by the giant axon system. For California market squid (Doryteuthis opalescens), maintaining essential behaviors like the escape response during environmental variations poses a major challenge as this species often encounters intrusions of cold, hypoxic offshore waters in its coastal spawning habitats. To explore the effects of hypoxia on locomotion and the underlying neural mechanisms, we made in vivo recordings of giant axon activity and simultaneous pressure inside the mantle cavity during escape ...
Source: Journal of Experimental Biology - April 15, 2019 Category: Biology Authors: Li, D. H., Gilly, W. F. Tags: Neuroethology RESEARCH ARTICLE Source Type: research

Using stable isotope analysis to study skin mucus exudation and renewal in fish [METHODS AND TECHNIQUES]
Antoni Ibarz, Borja Ordonez-Grande, Ignasi Sanahuja, Sergio Sanchez-Nuno, Jaume Fernandez-Borras, Josefina Blasco, and Laura Fernandez-Alacid Fish skin mucus is proposed as a novel target for the study of physiological condition and to conduct minimally invasive monitoring of fish. Whereas mucus composition has been a major interest of recent studies, no practical techniques have been proposed to gain understanding of the capacity and rhythm of production and exudation. Here, we used stable isotope analysis (SIA) with a labelled meal, packaged in gelatine capsules, to evaluate mucus production and renewal in a fish model,...
Source: Journal of Experimental Biology - April 15, 2019 Category: Biology Authors: Ibarz, A., Ordonez-Grande, B., Sanahuja, I., Sanchez-Nuno, S., Fernandez-Borras, J., Blasco, J., Fernandez-Alacid, L. Tags: METHODS AND TECHNIQUES Source Type: research

Biosonar interpulse intervals and pulse-echo ambiguity in four species of echolocating bats [RESEARCH ARTICLE]
James A. Simmons, Shizuko Hiryu, and Uday Shriram In complex biosonar scenes, the delay of echoes represents the spatial distribution of objects in depth. To avoid overlap of echo streams from successive broadcasts, individual echolocation sounds should only be emitted after all echoes of previous sounds have returned. However, close proximity of obstacles demands rapid pulse updates for steering to avoid collisions, which often means emitting a new sound before all of the previous echoes have returned. When two echo streams overlap, there is ambiguity about assigning echoes to the corresponding broadcasts. In laboratory ...
Source: Journal of Experimental Biology - April 15, 2019 Category: Biology Authors: Simmons, J. A., Hiryu, S., Shriram, U. Tags: Neuroethology RESEARCH ARTICLE Source Type: research

Co-opting evo-devo concepts for new insights into mechanisms of behavioural diversity [COMMENTARY]
Kim L. Hoke, Elizabeth Adkins-Regan, Andrew H. Bass, Amy R. McCune, and Mariana F. Wolfner We propose that insights from the field of evolutionary developmental biology (or ‘evo-devo’) provide a framework for an integrated understanding of the origins of behavioural diversity and its underlying mechanisms. Towards that goal, in this Commentary, we frame key questions in behavioural evolution in terms of molecular, cellular and network-level properties with a focus on the nervous system. In this way, we highlight how mechanistic properties central to evo-devo analyses – such as weak linkage, versatility, ...
Source: Journal of Experimental Biology - April 15, 2019 Category: Biology Authors: Hoke, K. L., Adkins-Regan, E., Bass, A. H., McCune, A. R., Wolfner, M. F. Tags: COMMENTARY Source Type: research

Ocean warming combined with lower omega-3 nutritional availability impairs the cardio-respiratory function of a marine fish [RESEARCH ARTICLE]
Marie Vagner, Eric Pante, Amelia Viricel, Thomas Lacoue-Labarthe, Jose-Luis Zambonino-Infante, Patrick Quazuguel, Emmanuel Dubillot, Valerie Huet, Herve Le Delliou, Christel Lefrancois, and Nathalie Imbert-Auvray Highly unsaturated fatty acids of the omega-3 series (HUFA) are major constituents of cell membranes, yet are poorly synthesised de novo by consumers. Their production, mainly supported by aquatic microalgae, has been decreasing with global change. The consequences of such reductions may be profound for ectotherm consumers, as temperature tightly regulates the HUFA content in cell membranes, maintaining their fun...
Source: Journal of Experimental Biology - April 15, 2019 Category: Biology Authors: Vagner, M., Pante, E., Viricel, A., Lacoue-Labarthe, T., Zambonino-Infante, J.-L., Quazuguel, P., Dubillot, E., Huet, V., Le Delliou, H., Lefrancois, C., Imbert-Auvray, N. Tags: Ecophysiology: responses to environmental stressors and change RESEARCH ARTICLE Source Type: research

Renal acid excretion contributes to acid-base regulation during hypercapnia in air-exposed swamp eel (Monopterus albus) [RESEARCH ARTICLE]
Phan Vinh Thinh, Do Thi Thanh Huong, Le Thi Hong Gam, Christian Damsgaard, Nguyen Thanh Phuong, Mark Bayley, and Tobias Wang The swamp eel (Monopterus albus) uses its buccal cavity to air-breathe while the gills are strongly reduced. They burrow into mud during the dry season, are highly tolerant of air-exposure, and experience severe hypoxia in both their natural habitat and in aquaculture. To study their ability to compensate for respiratory acidosis, we implanted catheters to sample both arterial blood and urine during hypercapnia (4% CO2) in either water and air, or during whole animal air-exposure. These hypercapnic c...
Source: Journal of Experimental Biology - April 11, 2019 Category: Biology Authors: Thinh, P. V., Huong, D. T. T., Gam, L. T. H., Damsgaard, C., Phuong, N. T., Bayley, M., Wang, T. Tags: RESEARCH ARTICLE Source Type: research