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 a profound influence on offspring phenotype both prenatally and postnatally. Egg maternal substances 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 concerned. We manipulated the yolk concentration of vitamin E and cor...
Source: Journal of Experimental Biology - May 16, 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

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 dur...
Source: Journal of Experimental Biology - May 16, 2019 Category: Biology Authors: do Amaral-Silva, L., Lambertz, M., Jose Zara, F., Klein, W., Gargaglioni, L. H., Bicego, K. C. 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 environment is of major importance for offspring health during later life. Endurance training during pregnancy is associated with positive metabolic adjustments and beneficial effects on the balance between pro-oxidants and antioxidants (redox state) in the offspring. Our hypothesis was that these changes could rely on mitochondrial adaptations in the offspring due to modifications of the fetal environment ...
Source: Journal of Experimental Biology - May 16, 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

Body condition impacts blood and muscle oxygen storage capacity of free-living beluga whales (Delphinapterus leucas) [RESEARCH ARTICLE]
Emily S. Choy, Kevin L. Campbell, Michael Berenbrink, James D. Roth, and Lisa L. Loseto Arctic marine ecosystems are currently undergoing rapid environmental changes. Over the past 20 years, individual growth rates of beluga whales (Delphinapterus leucas) have declined, which may be a response to climate change; however, scarcity of physiological data makes it difficult to gauge the adaptive capacity and resilience of the species. We explored relationships between body condition and physiological parameters pertaining to oxygen (O2) storage capacity in 77 beluga whales in the eastern Beaufort Sea. Muscle myoglobin concentr...
Source: Journal of Experimental Biology - May 16, 2019 Category: Biology Authors: Choy, E. S., Campbell, K. L., Berenbrink, M., Roth, J. D., Loseto, L. L. Tags: RESEARCH ARTICLE Source Type: research

Honey bees flexibly use two navigational memories when updating dance distance information [RESEARCH ARTICLE]
Arumoy Chatterjee, Ebi A. George, M. V. Prabhudev, Pallab Basu, and Axel Brockmann Honey bees can communicate navigational information which makes them unique amongst all prominent insect navigators. Returning foragers recruit nest mates to a food source by communicating flight distance and direction using a small scale walking pattern: the waggle dance. It is still unclear how bees transpose flight information to generate corresponding dance information. In single feeder shift experiments, we monitored for the first time how individual bees update dance duration after a shift of feeder distance. Interestingly, the majorit...
Source: Journal of Experimental Biology - May 16, 2019 Category: Biology Authors: Chatterjee, A., George, E. A., Prabhudev, M. V., Basu, P., Brockmann, A. Tags: RESEARCH ARTICLE Source Type: research

The sea chordophones make the mysterious /Kwa/: emitter identification of the dominating fish sound in Mediterranean seagrass meadows [RESEARCH ARTICLE]
This study used an inter-disciplinary approach to investigate the vocal abilities of Scorpaena spp.; morphological, histological and electrophysiological examinations have been interpreted together with visual and acoustic recordings conducted in semi-natural conditions. All observed Scorpaena spp. (S. porcus, S. scrofa and S. notata) share the same sonic apparatus at the level of the abdominal region. This apparatus, present in both males and females, consists of 3 bilaterally symmetrical muscular bundles, having 3 to 5 long tendons, which insert on ventral bony apophyses of the vertebral bodies. In all chordophones (stri...
Source: Journal of Experimental Biology - May 16, 2019 Category: Biology Authors: Bolgan, M., Soulard, J., Di Iorio, L., Gervaise, C., Lejeune, P., Gobert, S., Parmentier, E. Tags: RESEARCH ARTICLE Source Type: research

Effects of repeated daily acute heat challenge on the growth and metabolism of a cold-water stenothermal fish [RESEARCH ARTICLE]
Matthew M. Guzzo, Neil J. Mochnacz, Travis Durhack, Benjamin C. Kissinger, Shaun S. Killen, and Jason R. Treberg Temperature is an important environmental factor influencing fish physiology that varies both spatially and temporally in ecosystems. In small north-temperate lakes, cold water piscivores rely on nearshore prey; however, this region exceeds the optimal temperature of the foraging species during summer. To cope, piscivores make short excursions into the nearshore to feed and return to cold water to digest, but the physiological impacts of these repeated acute exposures to warm water are not well understood. We ex...
Source: Journal of Experimental Biology - May 16, 2019 Category: Biology Authors: Guzzo, M. M., Mochnacz, N. J., Durhack, T., Kissinger, B. C., Killen, S. S., Treberg, J. R. Tags: RESEARCH ARTICLE Source Type: research

Turtles maintain mitochondrial integrity but reduce mitochondrial respiratory capacity in the heart after cold-acclimation and anoxia [SHORT COMMUNICATION]
Amanda Bundgaard, Klaus Qvortrup, Lene Juel Rasmussen, and Angela Fago Mitochondria are important to cellular homeostasis, but can become a dangerous liability when cells recover from hypoxia. Anoxia-tolerant freshwater turtles show reduced mitochondrial respiratory capacity and production of reactive oxygen species (ROS) after prolonged anoxia, but the mechanisms are unclear. Here, we investigated whether this mitochondrial suppression originates from downregulation of mitochondrial content or intrinsic activity by comparing heart mitochondria from 1) warm (25°C) normoxic, 2) cold-acclimated (4°C) normoxic, and 3)...
Source: Journal of Experimental Biology - May 16, 2019 Category: Biology Authors: Bundgaard, A., Qvortrup, K., Rasmussen, L. J., Fago, A. Tags: SHORT COMMUNICATION Source Type: research

Optimal length, calcium sensitivity, and twitch characteristics of skeletal muscles from mdm mice with a deletion in N2A titin [RESEARCH ARTICLE]
Anthony L. Hessel, Venus Joumaa, Sydney Eck, Walter Herzog, and Kiisa C. Nishikawa During isometric contractions, the optimal length of skeletal muscles increases with decreasing activation. The underlying mechanism for this phenomenon is thought to be linked to length-dependence of Ca2+-sensitivity. Muscular dystrophy with myositis (mdm), a recessive titin mutation in mice, was used as a tool to study the role of titin in activation-dependence of optimal length and length-dependence of Ca2+ sensitivity. We measured the shift in optimal length between tetanic and twitch stimulation in mdm and wild type muscles, and the len...
Source: Journal of Experimental Biology - May 16, 2019 Category: Biology Authors: Hessel, A. L., Joumaa, V., Eck, S., Herzog, W., Nishikawa, K. C. Tags: RESEARCH ARTICLE Source Type: research

Morphometric models for estimating bite force in Mus and Rattus: mandible shape and size do better than lever-arm ratios [RESEARCH ARTICLE]
Samuel Ginot, Anthony Herrel, Julien Claude, and Lionel Hautier Morphological traits are frequently used as proxies for functional outputs such as bite force performance. This allows researchers to infer and interpret the impacts of functional variation, notably in adaptive terms. Despite their mechanical bases, the predictive power of these proxies for performance is not always tested. In particular, their accuracy at the intraspecific level is rarely assessed, and they have sometimes been shown to be unreliable. Here, we compare the performance of several morphological proxies in estimating in vivo bite force, across fiv...
Source: Journal of Experimental Biology - May 16, 2019 Category: Biology Authors: Ginot, S., Herrel, A., Claude, J., Hautier, L. Tags: RESEARCH ARTICLE Source Type: research

Unique evolution of vitamin A as an external pigment in tropical starlings [RESEARCH ARTICLE]
Ismael Galvan, Khaled Murtada, Alberto Jorge, Angel Rios, and Mohammed Zougagh Pigments are largely responsible for the appearance of organisms. Most biological pigments derive from the metabolism of shikimic acid (melanins), mevalonic acid (carotenoids) or levulinic acid (porphyrins), which thus generate the observed diversity of external phenotypes. Starlings are generally dark birds despite iridescence in feathers, but 10 % of species have evolved plumage pigmentation comprising bright colors that are known to be produced only by carotenoids. However, using micro-Raman spectroscopy, we have discovered that the bright ye...
Source: Journal of Experimental Biology - May 16, 2019 Category: Biology Authors: Galvan, I., Murtada, K., Jorge, A., Rios, A., Zougagh, M. Tags: RESEARCH ARTICLE Source Type: research

Marine larval vision suffers in low oxygen [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - May 13, 2019 Category: Biology Authors: Knight, K. Tags: INSIDE JEB 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. Therefore, the metabolic demands of visual systems 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 - May 13, 2019 Category: Biology Authors: McCormick, L. R., Levin, L. A., Oesch, N. W. Tags: Ecophysiology: responses to environmental stressors and change RESEARCH ARTICLE Source Type: research

Resource profitability, but not caffeine, affects individual and collective foraging in the stingless bee Plebeia droryana [RESEARCH ARTICLE]
We examined whether caffeine affects the foraging behaviour of the stingless bee Plebeia droryana, which frequently visits plants that produce caffeinated nectar and pollen. We trained bees to food sources containing field-realistic concentrations of sugar and caffeine. Caffeine did not cause P. droryana to increase foraging frequency and persistence. We observed P. droryana recruiting to food sources; however, this behaviour was also not affected by caffeine. Instead we found that higher sugar concentrations caused bees to increase foraging effort. Thus, unlike in other pollinators, foraging behaviour in this stingless be...
Source: Journal of Experimental Biology - May 13, 2019 Category: Biology Authors: Peng, T., Segers, F. H. I. D., Nascimento, F., Grüter, C. Tags: RESEARCH ARTICLE Source Type: research

The mineralocorticoid receptor contributes to barrier function of a model fish gill epithelium [RESEARCH ARTICLE]
This study considered how cortisol influenced model gill epithelium permeability and TJ properties by transcriptional knockdown of the gene encoding MR (mr-KD) using double-stranded RNA. Following mr-KD a significant reduction in MR protein abundance was observed in the epithelium. The mr-KD epithelium demonstrated reduced transepithelial resistance (TER) and increased the paracellular flux of [3H] polyethylene glycol (MW 400 kDa, PEG-400). Concurrently, mRNA abundance of gr2 and 11βhsd increased, indicating a possible compensatory response to mr-KD. Transcript abundance of claudin (cldn) -6, -8d, 23a and -28b decreas...
Source: Journal of Experimental Biology - May 13, 2019 Category: Biology Authors: Kolosov, D., Kelly, S. P. Tags: RESEARCH ARTICLE Source Type: research

Panorama similarity and navigational knowledge in the nocturnal bull ant, Myrmicia midas [RESEARCH ARTICLE]
Cody A. Freas and Ken Cheng Nocturnal ants forage and navigate during periods of reduced light, making detection of visual cues difficult, yet they are skilled visual navigators. These foragers retain visual panoramic memories both around the nest and along known routes for later use, be it to return to previously visited food sites or to the nest. Here, we explore the navigational knowledge of the nocturnal bull ant, Myrmecia midas, by investigating differences in nest-ward homing after displacement of three forager groups based on similarities in the panoramas between the release site and previously visited locations. Fo...
Source: Journal of Experimental Biology - May 13, 2019 Category: Biology Authors: Freas, C. A., Cheng, K. Tags: RESEARCH ARTICLE Source Type: research

Comparing thermal performance curves across traits: how consistent are they? [RESEARCH ARTICLE]
We examined the effects of time-scale of temperature exposure (mins/hours vs days/weeks) in altering the TPC shape, position and commonly used descriptors of the TPC- thermal optimum (TOPT), thermal limits (TMIN and TMAX) and thermal breadth (TBR). In addition we collated previously published estimates of TPCs for fecundity and egg-to-adult viability in D. melanogaster. We found that the descriptors of the TPCs varied across traits (egg-to-adult viability, SMR, activity and fecundity), but variation in TPCs within these traits was small across studies when measured at the same time-scales. The time-scale at which traits we...
Source: Journal of Experimental Biology - May 13, 2019 Category: Biology Authors: Kellermann, V., Chown, S. L., Schou, M. F., Aitkenhead, I., Janion-Scheepers, C., Clemson, A., Scott, M. T., Sgro, C. M. Tags: RESEARCH ARTICLE Source Type: research

Distinctive mechanisms underlie the emission of social electric signals of submission in Gymnotus omarorum [RESEARCH ARTICLE]
Virginia Comas, Kim Langevin, Ana Silva, and Michel Borde South American weakly electric fish (order Gymnotiformes) rely on a highly conserved and relatively fixed electromotor circuit to produce species-specific electric organ discharges (EOD) and a variety of meaningful adaptive EOD modulations. The command for each EOD arises from a medullary pacemaker nucleus composed by electrotonically coupled intrinsic pacemaker and bulbospinal projecting relay cells. During agonistic encounters Gymnotus omarorum signals submission by interrupting its EOD (offs) and by emitting transient high rate barrages of low amplitude discharge...
Source: Journal of Experimental Biology - May 13, 2019 Category: Biology Authors: Comas, V., Langevin, K., Silva, A., Borde, M. Tags: RESEARCH ARTICLE Source Type: research

A songbird compensates for wing molt during escape flights by reducing the molt gap and increasing angle-of-attack [RESEARCH ARTICLE]
In this study, we investigated whether and how birds adjust their escape flight behavior to compensate for the reduction in performance when flying with wing gaps. Using stereoscopic high-speed videography, we filmed 146 upward-directed escape flights of 19 and 22 pied flycatchers (Ficedula hypoleuca) with and without simulated molt gaps, respectively. We then reconstructed the three-dimensional body and wing movements throughout each maneuver. By comparing flights with and without gaps, we determined how wing molt gaps affected wing morphology, escape flight performance, and how the birds adjusted their flight kinematics ...
Source: Journal of Experimental Biology - May 13, 2019 Category: Biology Authors: Tomotani, B. M., Muijres, F. T. Tags: RESEARCH ARTICLE Source Type: research

Goats decrease hindlimb stiffness when walking over compliant surfaces [RESEARCH ARTICLE]
This study investigated how goats adjust the stiffness of their hindlimbs to accommodate surfaces of different stiffness. Goats provide a compelling animal model for studying leg stiffness modulation, because they skillfully ambulate over a range of substrates that vary in compliance. To investigate the adjustments that goats make when walking over such substrates, ground reaction forces and three-dimensional trajectories of hindlimb markers were recorded as goats walked on rigid, rubber, and foam surfaces. Net joint moments, powers, and work at the hip, knee, ankle and metatarsophalangeal joints were estimated throughout ...
Source: Journal of Experimental Biology - May 13, 2019 Category: Biology Authors: Clites, T. R., Arnold, A. S., Singh, N. M., Kline, E., Chen, H., Tugman, C., Billadeau, B., Biewener, A. A., Herr, H. M. Tags: RESEARCH ARTICLE Source Type: research

Eccentric resistance training and {beta}-Hydroxy-{beta}-methylbutyrate free acid affects muscle PGC-1{alpha} expression and serum irisin, nesfatin-1 and resistin [RESEARCH ARTICLE]
Hossein Shirvani, Saleh Rahmati-Ahmadabad, David Robert Broom, and Reza Mirnejad The hypothalamus controls metabolism and feeding behavior via several signals with other tissues. Exercise and supplements can change hypothalamic signaling pathways, so the present study investigated the influence of eccentric resistance training and β-Hydroxy-β-methylbutyrate free acid supplement on PGC-1α expression, serum irisin, nesfatin-1 and resistin concentrations. Thirty-two male rats (8 weeks old, 200±17 g body mass) were randomized to control (CON), β-Hydroxy-β-methylbutyrate free acid (HMB) suppleme...
Source: Journal of Experimental Biology - May 13, 2019 Category: Biology Authors: Shirvani, H., Rahmati-Ahmadabad, S., Broom, D. R., Mirnejad, R. Tags: RESEARCH ARTICLE Source Type: research

Differential glycogen utilization in shark acid- and base-regulatory gill cells [SHORT COMMUNICATION]
Jinae N. Roa and Martin Tresguerres Na+/K+-ATPase (NKA)- and vacuolar H+-ATPase (VHA)-rich cells in shark gills respectively secrete excess acid and base to seawater to maintain blood acid-base homeostasis. Both cell types are rich in mitochondria indicating high ATP demand; however, their metabolic fuel is unknown. Here we report that NKA- and VHA-rich cells have large glycogen stores. Glycogen abundance in NKA-rich cells was lower in starved sharks compared to 24h post-fed sharks, reflecting higher energy demand for acid secretion during normal activity and glycogen replenishment during the post-feeding period. Conversel...
Source: Journal of Experimental Biology - May 13, 2019 Category: Biology Authors: Roa, J. N., Tresguerres, M. Tags: SHORT COMMUNICATION Source Type: research

Selenoprotein T as a new positive inotrope in the goldfish Carassius auratus [RESEARCH ARTICLE]
This study aimed to evaluate the cardiac expression of SELENOT, and the effects of exogenous PSELT (a 43-52 SELENOT derived-peptide) on the heart function of C. auratus, a hypoxia tolerance fish model. We found that SELENOT was expressed in cardiac extracts of juvenile and adult fish, located in the sarcoplasmic reticulum (SR) together with calsequestrin-2. Expression increased under acute hypoxia. On ex vivo isolated and perfused goldfish heart preparations, under normoxia, PSELT dose-dependently increased Stroke Volume (SV), Cardiac Output (Q), and Stroke Work (SW), by involving cAMP, PKA, L-type calcium channels, SERCA2...
Source: Journal of Experimental Biology - May 13, 2019 Category: Biology Authors: Rosa, M., Alfonsina, G., Sandra, I., Loubna, B., Serena, L., Yamine, M. B., Mariacristina, F., Carmine, R., Tommaso, A., Youssef, A., Carmela, C. M. Tags: RESEARCH ARTICLE Source Type: research

Multichannel Stroboscopic Videography (MSV): A technique for visualizing multiple channels for behavioral measurements [METHODS [amp ] TECHNIQUES]
Alberto P. Soto, Theodora Po, and Matthew J. McHenry Biologists commonly visualize different features of an organism using distinct sources of illumination. Multichannel imaging has largely not been applied to behavioral studies due to the challenges posed by a moving subject. We address this challenge with the technique of Multichannel Stroboscopic Videography (MSV), which synchronizes multiple strobe lights with video exposures of a single camera. We illustrate the utility of this approach with kinematic measurements of a walking cockroach (Gromphadorhina portentosa) and calculations of the pressure field around a swimmi...
Source: Journal of Experimental Biology - May 13, 2019 Category: Biology Authors: Soto, A. P., Po, T., McHenry, M. J. Tags: METHODS [amp ] TECHNIQUES Source Type: research

Food-derived volatiles enhance consumption in Drosophila melanogaster [RESEARCH ARTICLE]
Carolina E. Reisenman and Kristin Scott Insects use multiple sensory modalities when searching for and accepting a food source, in particular odor and taste cues. Food-derived odorants are generally involved in mediating long-and short-range attraction. Taste cues, on the other hand, act directly by contact with the food source, promoting the ingestion of nutritious food and the avoidance of toxic substances. It is possible, however, that insects integrate information from these sensory modalities during the process of feeding itself. Here, using a simple feeding assay, we investigated whether odors modulate food consumpti...
Source: Journal of Experimental Biology - May 13, 2019 Category: Biology Authors: Reisenman, C. E., Scott, K. 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 test...
Source: Journal of Experimental Biology - May 10, 2019 Category: Biology Authors: Cosman, M. N., Britz, H. M., Rolian, C. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

Cranial kinesis in the miniaturised lizard Ablepharus kitaibelii (Squamata: Scincidae) [RESEARCH ARTICLE]
Stephan Handschuh, Nikolay Natchev, Stefan Kummer, Christian J. Beisser, Patrick Lemell, Anthony Herrel, and Vladislav Vergilov Cranial kinesis refers to intracranial movements in the vertebrate skull that do not concern the jaw joint, the middle ear or the hypobranchial skeleton. Different kinds of cranial kinesis have been reported for lizards, including mesokinesis, metakinesis, amphikinesis (simultaneous mesokinesis and metakinesis) and streptostyly. Streptostyly is considered relatively widespread within lizards, whereas mesokinesis has been documented only for geckos, varanids and anguids. The present study investig...
Source: Journal of Experimental Biology - May 10, 2019 Category: Biology Authors: Handschuh, S., Natchev, N., Kummer, S., Beisser, C. J., Lemell, P., Herrel, A., Vergilov, V. Tags: RESEARCH ARTICLE 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 large number 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 co...
Source: Journal of Experimental Biology - May 10, 2019 Category: Biology Authors: Tsvetkov, N., Cook, C. N., Zayed, A. Tags: RESEARCH ARTICLE Source Type: research

Clownfish larvae J-curl to catch copepods [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - May 9, 2019 Category: Biology Authors: Knight, K. Tags: INSIDE JEB 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. It burrows into mud during the dry season, is highly tolerant of air exposure, and experiences severe hypoxia both in its natural habitat and in aquaculture. To study the ability of M. albus to compensate for respiratory acidosis, we implanted catheters to sample both arterial blood and urine during hypercapnia (4% CO2) in either water or air, or during whole-animal air exposure. These hyper...
Source: Journal of Experimental Biology - May 9, 2019 Category: Biology Authors: Thinh, P. V., Thanh Huong, D. T., Gam, L. T. H., Damsgaard, C., Phuong, N. T., Bayley, M., Wang, T. Tags: RESEARCH ARTICLE Source Type: research

Fatigue and recovery measured with dynamic properties versus isometric force: effects of exercise intensity [RESEARCH ARTICLE]
Renata L. Krüger, Saied Jalal Aboodarda, Libia Marcela Jaimes, Brian R. MacIntosh, Pierre Samozino, and Guillaume Y. Millet Although fatigue can be defined as an exercise-related decrease in maximal power or isometric force, most studies have assessed only isometric force. The main purpose of this experiment was to compare dynamic measures of fatigue [maximal torque (Tmax), maximal velocity (Vmax) and maximal power (Pmax)] with measures associated with maximal isometric force [isometric maximal voluntary contraction (IMVC) and maximal rate of force development (MRFD)] 10 s after different fatiguing exercises and du...
Source: Journal of Experimental Biology - May 9, 2019 Category: Biology Authors: Krüger, R. L., Aboodarda, S. J., Jaimes, L. M., MacIntosh, B. R., Samozino, P., Millet, G. Y. Tags: 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. Although 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 ...
Source: Journal of Experimental Biology - May 9, 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

Castaway cottonmouths depend on rain to slake thirst [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - May 8, 2019 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

A new, practicable and economical cage design for experimental studies on small honey bee colonies [METHODS AND 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, as opposed to individual workers, to be managed well in captivity. (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - May 8, 2019 Category: Biology Authors: Sonter, C. A., Rader, R., Wilson, S. C. Tags: METHODS AND TECHNIQUES 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 concentrations in all ammonia-N groups increased significantly between 3 and 12 h. Cortisol increased significantly between 3 and 24 h. All hormones except crustacean hyperglycemic hormone were reduced to control levels. mRNA abundance of guanylyl cyclase increased sign...
Source: Journal of Experimental Biology - May 8, 2019 Category: Biology Authors: Si, L., Pan, L., Wang, H., Zhang, X. Tags: RESEARCH ARTICLE Source Type: research

Avian surface reconstruction in free flight with application to flight stability analysis of a barn owl and peregrine falcon [RESEARCH ARTICLE]
Nicholas E. Durston, Xue Wan, Jian G. Liu, and Shane P. Windsor Birds primarily create and control the forces necessary for flight through changing the shape and orientation of their wings and tail. Their wing geometry is characterised by complex variation in parameters such as camber, twist, sweep and dihedral. To characterise this complexity, a multi-view stereo-photogrammetry setup was developed for accurately measuring surface geometry in high resolution during free flight. The natural patterning of the birds was used as the basis for phase correlation-based image matching, allowing indoor or outdoor use while being n...
Source: Journal of Experimental Biology - May 8, 2019 Category: Biology Authors: Durston, N. E., Wan, X., Liu, J. G., Windsor, S. P. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

Early-career researchers: an interview with Heath MacMillan [CONVERSATION]
Heath MacMillan is an Assistant Professor at Carleton University, Canada, where he studies the physiological mechanisms limiting ectotherm performance. He received his Bachelor's degree in biology from the University of Western Ontario, Canada, in 2008 before completing his PhD in 2013 with Brent Sinclair and Jim Staples at the same institution. After undertaking a postdoc with Johannes Overgaard at Aarhus University, Denmark, MacMillan was awarded a Banting Fellowship, which he took in the laboratory of Andrew Donini at York University, Canada. (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - May 7, 2019 Category: Biology Tags: CONVERSATION Source Type: research

Water relations of an insular pit viper [RESEARCH ARTICLE]
Mark R. Sandfoss and Harvey B. Lillywhite Colonization of novel habitats often requires plasticity or adaptation to local conditions. There is a critical need to maintain hydration in terrestrial environments having limited water. Atypical populations of Florida cottonmouth snakes, Agkistrodon conanti, inhabit continental islands with no permanent sources of fresh water. Here, we report investigations related to how these insular snakes maintain water balance considering the mainland conspecifics are semi-aquatic and typically associate with freshwater mesic habitats. We tested three hypotheses related to water relations ...
Source: Journal of Experimental Biology - May 7, 2019 Category: Biology Authors: Sandfoss, M. R., Lillywhite, H. B. 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 capacity that salticids might have for visual performance under low ambient light levels. Here, we investigated the capacity of two salticid species, Cyrba algerina from Portugal and Cyrba ocellata from Kenya, to perform two specific visual tasks under low ambient light levels. We used lures made from spiders and m...
Source: Journal of Experimental Biology - May 7, 2019 Category: Biology Authors: Cerveira, A. M., Jackson, R. R., Nelson, X. J. Tags: RESEARCH ARTICLE Source Type: research

Phenotypic plasticity in locomotor performance of a monophyletic group of weevils accords with the 'warmer is better hypothesis [RESEARCH ARTICLE]
In this study, we tested the full suite of hypotheses by investigating acclimation responses of locomotor performance for nine populations of five species of sub-Antarctic weevils, using static and fluctuating temperatures. Species showed typical locomotion thermal performance curves with temperature of the maximum speed (Topt) ranging between 22.3±1.7°C (mean±s.e.m.) and 31.1±0.7°C. For most species, Topt was not affected by acclimation. For maximum speed (Umax), significant, positive effects of acclimation were found for all species except a supralittoral one. Individuals acclimated to 0°...
Source: Journal of Experimental Biology - May 7, 2019 Category: Biology Authors: Treasure, A. M., Chown, S. L. Tags: RESEARCH ARTICLE Source Type: research

Tibialis anterior tendinous tissue plays a key role in energy absorption during human walking [RESEARCH ARTICLE]
Jayishni N. Maharaj, Andrew G. Cresswell, and Glen A. Lichtwark The elastic tendinous tissues of distal lower limb muscles can improve the economy of walking and running, amplify the power generated by a muscle as well as absorb energy. This paper explores the behaviour of the tibialis anterior (TA) muscle and its tendinous tissue during gait, as it absorbs energy during contact and controls foot position during swing. Simultaneous measurements of ultrasound, surface electromyography and 3-dimensional motion capture with musculoskeletal modelling from twelve healthy participants were recorded as they walked at preferred an...
Source: Journal of Experimental Biology - May 7, 2019 Category: Biology Authors: Maharaj, J. N., Cresswell, A. G., Lichtwark, G. A. Tags: RESEARCH ARTICLE Source Type: research

Resource profitability, but not caffeine, affects individual and collective foraging in the stingless bee Plebeia droryana [RESEARCH ARTICLE]
We examined whether caffeine affects the foraging behaviour of the stingless bee Plebeia droryana, which frequently visits plants that produce caffeinated nectar and pollen. We trained bees to food sources containing field-realistic concentrations of sugar and caffeine. Caffeine did not cause P. droryana to increase foraging frequency and persistency. We observed P. droryana recruiting to food sources, however, this behaviour was also not affected by caffeine. Instead we found that higher sugar concentrations caused bees to increase foraging effort. Thus, unlike in other pollinators, foraging behaviour in this stingless be...
Source: Journal of Experimental Biology - May 7, 2019 Category: Biology Authors: Peng, T., Segers, F. H. I. D., Nascimento, F., Grüter, C. Tags: RESEARCH ARTICLE Source Type: research

Motion-in-depth perception and prey capture in the praying mantis Sphodromantis lineola [RESEARCH ARTICLE]
Vivek Nityananda, Coline Joubier, Jerry Tan, Ghaith Tarawneh, and Jenny C. A. Read Perceiving motion-in-depth is essential to detecting approaching or receding objects, predators and prey. This can be achieved using several cues, including binocular stereoscopic cues such as changing disparity and interocular velocity differences, and monocular cues such as looming. While these have been studied in detail in humans, only looming responses have been well characterized in insects and we know nothing about the role of stereo cues and how they might interact with looming cues. We used our 3D insect cinema in a series of experi...
Source: Journal of Experimental Biology - May 7, 2019 Category: Biology Authors: Nityananda, V., Joubier, C., Tan, J., Tarawneh, G., Read, J. C. A. Tags: RESEARCH ARTICLE Source Type: research

UV-light perception is modulated by the odour element of an olfactory-visual compound in restrained honeybees [RESEARCH ARTICLE]
Mira C. Becker, Wolfgang Rössler, and Martin Fritz Strube-Bloss Honeybees use visual and olfactory cues to detect flowers during foraging trips. Hence, the reward association of a nectar source is a multimodal construct which has at least two major components – olfactory and visual cues. How both sensory modalities are integrated to form a common reward association and whether and how they may interfere, is an open question. The present study used stimulation with UV, blue and green light to evoke distinct photoreceptor activities in the compound eye and two odour components (Geraniol, Citronellol). To test if a co...
Source: Journal of Experimental Biology - May 7, 2019 Category: Biology Authors: Becker, M. C., Rössler, W., Strube-Bloss, M. F. Tags: RESEARCH ARTICLE Source Type: research

Reproductive fitness of Drosophila is maximised by optimal developmental temperature [RESEARCH ARTICLE]
Peter Klepsatel, Thirnahalli Nagaraj Girish, Heinrich Dircksen, and Martina Galikova Whether the character of developmental plasticity is adaptive or non-adaptive has often been a matter of controversy. Although thermal developmental plasticity has been studied in Drosophila for several traits, it is not entirely clear how it affects reproductive fitness. We, therefore, investigated how developmental temperature affects reproductive performance (early fecundity and egg-to-adult viability) of wild-caught Drosophila melanogaster. We have tested competing hypotheses on the character of developmental thermal plasticity using a...
Source: Journal of Experimental Biology - May 7, 2019 Category: Biology Authors: Klepsatel, P., Girish, T. N., Dircksen, H., Galikova, M. Tags: RESEARCH ARTICLE Source Type: research

Effects of temperature and salinity on body fluid dynamics and metabolism in the estuarine Diamond-backed Terrapin (Malaclemys terrapin) [RESEARCH ARTICLE]
Amanda Southwood Williard, Leigh Anne Harden, T. Todd Jones, and Stephen R. Midway The diamondback terrapin is the only temperate turtle species that exclusively inhabits estuarine habitats. Morphological, behavioral and physiological features contribute to the terrapin's ability to regulate body fluid osmotic pressure in a euryhaline environment. Low integument permeability combined with aquatic-terrestrial shuttling behavior limits passive exchange of water and salts with the environment, and terrapins regulate active uptake of salts via alterations in drinking and feeding behavior. The lachrymal salt gland facilitates e...
Source: Journal of Experimental Biology - May 7, 2019 Category: Biology Authors: Williard, A. S., Harden, L. A., Jones, T. T., Midway, S. R. Tags: RESEARCH ARTICLE Source Type: research

Septate junction in the distal ileac plexus of larval lepidopteran Trichoplusia ni: alterations in paracellular permeability during ion transport reversal [RESEARCH ARTICLE]
Dennis Kolosov, Sima Jonusaite, Andrew Donini, Scott P. Kelly, and Michael J. O'Donnell The Malpighian tubules (MTs) and hindgut together act as the functional kidney in insects. MTs of caterpillars are notably complex and consist of several regions that display prominent differences in ion transport. The distal ileac plexus (DIP) is a region of Malpighian tubule that is of particular interest because it switches from ion secretion to ion reabsorption in larvae fed on ion-rich diets. The pathways of solute transport in the DIP are not well understood, but one potential route is the paracellular pathway between epithelial c...
Source: Journal of Experimental Biology - May 7, 2019 Category: Biology Authors: Kolosov, D., Jonusaite, S., Donini, A., Kelly, S. P., O'Donnell, M. J. Tags: RESEARCH ARTICLE Source Type: research

Finding the peak of dynamic oxygen uptake during fatiguing exercise in fish [METHODS [amp ] TECHNIQUES]
Yangfan Zhang, Matthew J. H. Gilbert, and Anthony P. Farrell As fish approach fatigue at high water velocities in a critical swimming speed (Ucrit) test, their swimming mode and oxygen cascade typically move to an unsteady state because they adopt an unsteady, burst-and-glide swimming mode despite a constant, imposed workload. However, conventional MO2 sampling intervals (5-20 min) tend to smooth any dynamic fluctuations in active MO2 (MO2active) and thus likely underestimate the peak MO2active. Here, we used rainbow trout (Oncorhynchus mykiss) to explore the dynamic nature of MO2active near Ucrit by using various sampling...
Source: Journal of Experimental Biology - May 3, 2019 Category: Biology Authors: Zhang, Y., Gilbert, M. J. H., Farrell, A. P. Tags: METHODS [amp ] TECHNIQUES Source Type: research

Plastic changes in brain morphology in relation to learning and environmental enrichment in the guppy (Poecilia reticulata) [RESEARCH ARTICLE]
Stephanie Fong, Severine D. Buechel, Annika Boussard, Alexander Kotrschal, and Niclas Kolm Despite the common assumption that the brain is mainly malleable to surrounding conditions during ontogeny, plastic neural changes can occur also in adulthood. One of the driving forces responsible for alterations in brain morphology is increasing environmental complexity that may demand for enhanced cognitive abilities (e.g. attention, memory and learning). However, studies looking at the relationship between brain morphology and learning are scarce. Here, we tested the effects of both learning and environmental enrichment on neural...
Source: Journal of Experimental Biology - May 3, 2019 Category: Biology Authors: Fong, S., Buechel, S. D., Boussard, A., Kotrschal, A., Kolm, N. Tags: RESEARCH ARTICLE Source Type: research

Repeated stimulation of the pituitary-adrenal axis alters offspring phenotype of a wild passerine [RESEARCH ARTICLE]
In this study I simulated the effect of repeated acute stress on offspring phenotype in free-living pied flycatchers (Ficedula hypoleuca) by administering adrenocorticotropic hormone (ACTH) to nestlings for 6 days. The results showed that frequent induction of stress responses by ACTH injections, independently of parental care, adversely affected offspring final body size, wing length and baseline corticosterone levels. Nestling behavioural activity did not differ between ACTH- and saline-treated groups during exposure to control sounds while behavioural activity during exposure to alarm calls was reduced in manipulated of...
Source: Journal of Experimental Biology - May 3, 2019 Category: Biology Authors: Tilgar, V. Tags: RESEARCH ARTICLE Source Type: research