Propulsive design principles in a multi-jet siphonophore [RESEARCH ARTICLE]
Kelly R. Sutherland, Brad J. Gemmell, Sean P. Colin, and John H. Costello Coordination of multiple propulsors can provide performance benefits in swimming organisms. Siphonophores are marine colonial organisms that orchestrate the motion of multiple swimming zooids for effective swimming. However, the kinematics at the level of individual swimming zooids (nectophores) have not been examined in detail. We used high speed, high resolution microvideography and particle image velocimetry (PIV) of the physonect siphonophore, Nanomia bijuga, to study the motion of the nectophores and the associated fluid motion during jetting an...
Source: Journal of Experimental Biology - February 27, 2019 Category: Biology Authors: Sutherland, K. R., Gemmell, B. J., Colin, S. P., Costello, J. H. Tags: RESEARCH ARTICLE Source Type: research

Different incubation patterns affect selective antimicrobial properties of the egg interior: experimental evidence from eggs of precocial and altricial birds [RESEARCH ARTICLE]
This study is the first to experimentally demonstrate that different incubation patterns may have selective antimicrobial potentials mediated by species-specific effects on antimicrobial components in the egg white. (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 27, 2019 Category: Biology Authors: Svobodova, J., Smidova, L., Gvozdikova Javurkova, V. Tags: RESEARCH ARTICLE Source Type: research

Nathusius' bats optimize long-distance migration by flying at maximum range speed [RESEARCH ARTICLE]
Sara A. Troxell, Marc W. Holderied, Gunars Petersons, and Christian C. Voigt Aerial migration is the fastest, yet most energetically demanding way of seasonal movement between habitats. However, for many taxa, and bats in particular, we lack a clear understanding of the energy requirements for migration. Here, we examined the energetic cost and flight speed of the long-distance migratory Nathusius’ bat (Pipistrellus nathusii). We measured flight metabolism in relation to airspeed in a wind tunnel, inferred the optimal traveling speed over long distances, i.e. maximum range speed, and compared this value with flight ...
Source: Journal of Experimental Biology - February 26, 2019 Category: Biology Authors: Troxell, S. A., Holderied, M. W., Petersons, G., Voigt, C. C. Tags: RESEARCH ARTICLE Source Type: research

Bee and floral traits affect the characteristics of the vibrations experienced by flowers during buzz pollination [RESEARCH ARTICLE]
Blanca Arroyo-Correa, Ceit Beattie, and Mario Vallejo-Marin During buzz pollination, bees use their indirect flight muscles to produce vibrations that are transmitted to the flowers and result in pollen release. Although buzz pollination has been known for>100 years, we are still in the early stages of understanding how bee and floral characteristics affect the production and transmission of floral vibrations. Here, we analysed floral vibrations produced by four closely related bumblebee taxa (Bombus spp.) on two buzz-pollinated plants species (Solanum spp.). We measured floral vibrations transmitted to the flower...
Source: Journal of Experimental Biology - February 25, 2019 Category: Biology Authors: Arroyo-Correa, B., Beattie, C., Vallejo-Marin, M. Tags: RESEARCH ARTICLE Source Type: research

Mechanical properties of the wave-swept kelp Egregia menziesii change with season, growth rate and herbivore wounds [RESEARCH ARTICLE]
Nicholas P. Burnett and M. A. R. Koehl The resistance of macroalgae to damage by hydrodynamic forces depends on the mechanical properties of their tissues. Although factors such as water-flow environment, algal growth rate and damage by herbivores have been shown to influence various material properties of macroalgal tissues, the interplay of these factors as they change seasonally and affect algal mechanical performance has not been worked out. We used the perennial kelp Egregia menziesii to study how the material properties of the rachis supporting a frond changed seasonally over a 2 year period, and how those chan...
Source: Journal of Experimental Biology - February 25, 2019 Category: Biology Authors: Burnett, N. P., Koehl, M. A. R. Tags: RESEARCH ARTICLE Source Type: research

Unexpected eye fat pad likely helps ground squirrels wake up [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 22, 2019 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Identification of a lipid-rich depot in the orbital cavity of the thirteen-lined ground squirrel [SHORT COMMUNICATION]
Amanda D. V. MacCannell, Kevin J. Sinclair, Glenn J. Tattersall, Charles A. McKenzie, and James F. Staples We discovered a previously undescribed orbital lipid depot in the thirteen-lined ground squirrel during the first ever magnetic resonance image (MRI) of this common experimental model of mammalian hibernation. In animals housed at constant ambient temperatures (5°C or 25°C, 12 h:12 h light:dark photoperiod), the volume of this depot increased in the autumn and decreased in the spring, suggesting an endogenous circannual pattern. Water-fat MRI revealed that throughout the year this depot is composed ...
Source: Journal of Experimental Biology - February 22, 2019 Category: Biology Authors: MacCannell, A. D. V., Sinclair, K. J., Tattersall, G. J., McKenzie, C. A., Staples, J. F. Tags: SHORT COMMUNICATION Source Type: research

Drosophila female fertility and juvenile hormone metabolism depends on the type of Wolbachia infection [RESEARCH ARTICLE]
Nataly E. Gruntenko, Evgenia K. Karpova, Natalya V. Adonyeva, Olga V. Andreenkova, Elena V. Burdina, Yury Yu. Ilinsky, Roman A. Bykov, Petr N. Menshanov, and Inga Yu. Rauschenbach Maternally inherited intracellular bacteria Wolbachia cause both parasitic and mutualistic effects on their numerous insect hosts, including manipulating the host reproductive system in order to increase the bacteria spreading in a host population, and increasing the host fitness. Here, we demonstrate that the type of Wolbachia infection determines the effect on Drosophila melanogaster egg production as a proxy for fecundity, and metabolism of j...
Source: Journal of Experimental Biology - February 22, 2019 Category: Biology Authors: Gruntenko, N. E., Karpova, E. K., Adonyeva, N. V., Andreenkova, O. V., Burdina, E. V., Ilinsky, Y. Y., Bykov, R. A., Menshanov, P. N., Rauschenbach, I. Y. Tags: RESEARCH ARTICLE Source Type: research

Dissecting cause from consequence: a systematic approach to thermal limits [COMMENTARY]
Heath A. MacMillan Thermal limits mark the boundaries of ectotherm performance, and are increasingly appreciated as strong correlates and possible determinants of animal distribution patterns. The mechanisms setting the thermal limits of ectothermic animals are under active study and rigorous debate as we try to reconcile new observations in the lab and field with the knowledge gained from a long history of research on thermal adaptation. Here, I provide a perspective on our divided understanding of the mechanisms setting thermal limits of ectothermic animals. I focus primarily on the fundamental differences between high ...
Source: Journal of Experimental Biology - February 22, 2019 Category: Biology Authors: MacMillan, H. A. Tags: Ecophysiology: responses to environmental stressors and change COMMENTARY Source Type: research

Compliant legs enable lizards to maintain high running speeds on complex terrains [RESEARCH ARTICLE]
Francois Druelle, Jana Goyens, Menelia Vasilopoulou-Kampitsi, and Peter Aerts Substrate variations are likely to compel animal performance in natural environments, as running over complex terrains challenges the dynamic stability of the body differently in each step. Yet, being able to negotiate complex terrains at top speed is a strong advantage for animals that have to deal with predators and evasive prey. Only little is known on how animals negotiate such terrain variability at high speed. We investigated this in fast running Acanthodactylus boskianus lizards, by measuring their 3D kinematics using four synchronized hig...
Source: Journal of Experimental Biology - February 22, 2019 Category: Biology Authors: Druelle, F., Goyens, J., Vasilopoulou-Kampitsi, M., Aerts, P. Tags: RESEARCH ARTICLE Source Type: research

Antioxidant response to acute cold exposure and during recovery in juvenile Chinese soft-shelled turtles (Pelodiscus sinensis) [RESEARCH ARTICLE]
Bo-Jian Chen, Wen-Yi Zhang, Cui-Juan Niu, Wen-Jie Li, Hui Jia, and Kenneth B. Storey The antioxidant defense protects turtles from oxidative stress caused by adverse environment conditions, such as acute thermal fluctuations. However, it remains unclear how these defenses work. The present study examined changes in key enzymes of the enzymatic antioxidant system and the glutathione (GSH) system at both the mRNA and enzyme activity levels during acute cold exposure and recovery in juvenile Chinese soft-shelled turtles, Pelodiscus sinensis. Transcript levels of the upstream regulator NF-E2-related factor 2 (Nrf2) were also ...
Source: Journal of Experimental Biology - February 21, 2019 Category: Biology Authors: Chen, B.-J., Zhang, W.-Y., Niu, C.-J., Li, W.-J., Jia, H., Storey, K. B. Tags: RESEARCH ARTICLE Source Type: research

Metabolic fuel use after feeding in the zebrafish (Danio rerio): a respirometric analysis [SHORT COMMUNICATION]
Marcio S. Ferreira, Chris M. Wood, Till S. Harter, Giorgi Dal Pont, Adalberto L. Val, and Philip G. D. Matthews We used respirometric theory and a new respirometry apparatus to assess, for the first time, the sequential oxidation of the major metabolic fuels during the post-prandial period (10 h) in adult zebrafish fed with commercial pellets (51% protein, 2.12% ration). Compared with a fasted group, fed fish presented peak increases of oxygen consumption (78%), and carbon dioxide (80%) and nitrogen excretion rates (338%) at 7–8 h, and rates remained elevated at 10 h. The respiratory quotient increase...
Source: Journal of Experimental Biology - February 21, 2019 Category: Biology Authors: Ferreira, M. S., Wood, C. M., Harter, T. S., Dal Pont, G., Val, A. L., Matthews, P. G. D. Tags: SHORT COMMUNICATION Source Type: research

Brief exposure to intense turbulence induces a sustained life-history shift in echinoids [RESEARCH ARTICLE]
Matthew C. Ferner, Jason Hodin, Gabriel Ng, and Brian Gaylord In coastal ecosystems, attributes of fluid motion can prompt animal larvae to rise or sink in the water column and to select microhabitats within which they attach and commit to a benthic existence. In echinoid (sea urchin and sand dollar) larvae living along wave-exposed shorelines, intense turbulence characteristic of surf zones can cause individuals to undergo an abrupt life-history shift characterized by precocious entry into competence – the stage at which larvae will settle and complete metamorphosis in response to local cues. However, the mechanist...
Source: Journal of Experimental Biology - February 21, 2019 Category: Biology Authors: Ferner, M. C., Hodin, J., Ng, G., Gaylord, B. Tags: RESEARCH ARTICLE Source Type: research

Pecking not so bird-brained after all [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 20, 2019 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Bark beetles use a spring-loaded mechanism to produce variable song patterns [SHORT COMMUNICATION]
Amanda A. Lindeman and Jayne E. Yack Many insects vary their song patterns to communicate different messages, but the underlying biomechanisms are often poorly understood. Here, we report on the mechanics of sound production and variation in an elytro-tergal stridulator, male Dendroctonus valens bark beetles. Using ablation experiments coupled with high-speed video and audio recordings, we show that: (1) chirps are produced using a stridulatory file on the left elytron (forewing) and a protrusion (plectrum) on the seventh abdominal segment; (2) chirps are produced by ‘spring stridulation’, a catch-and-release ...
Source: Journal of Experimental Biology - February 20, 2019 Category: Biology Authors: Lindeman, A. A., Yack, J. E. Tags: SHORT COMMUNICATION Source Type: research

Rapid adjustment of pecking trajectory to prism-induced visual shifts in crows as compared with pigeons [RESEARCH ARTICLE]
Hiroshi Matsui and Ei-Ichi Izawa Pecking in birds is analogous to reaching and grasping movements in primates. Earlier studies on visuomotor control in birds, which were conducted mostly in pigeons, suggested that avian pecking is controlled feedforwardly, and is out of the control of visual guidance during movement. However, recent studies using crows suggested a role of vision in pecking control during movement. To unveil what visuomotor mechanisms underlie the flexibility of pecking in crows, we examined whether pigeons and crows adjust their pecking to the visual distortion induced by prisms. Because prisms induce vis...
Source: Journal of Experimental Biology - February 20, 2019 Category: Biology Authors: Matsui, H., Izawa, E.-I. Tags: RESEARCH ARTICLE Source Type: research

Contraction of atrial smooth muscle reduces cardiac output in perfused turtle hearts [RESEARCH ARTICLE]
William Joyce, Michael Axelsson, and Tobias Wang Unusual undulations in resting tension (tonus waves) were described in isolated atria from freshwater turtle more than a century ago. These tonus waves were soon after married with the histological demonstration of a rich layer of smooth muscle on the luminal side of the atrial wall. Research thereafter waned and the functional significance of this smooth muscle has remained obscure. Here we provide evidence that contraction of the smooth muscle in the atria may be able to change cardiac output in turtle hearts. In in situ perfused hearts of the red-eared slider turtle (Trac...
Source: Journal of Experimental Biology - February 20, 2019 Category: Biology Authors: Joyce, W., Axelsson, M., Wang, T. Tags: RESEARCH ARTICLE Source Type: research

Variable vision in variable environments: the visual system of an invasive cichlid (Cichla monoculus, Agassiz, 1831) in Lake Gatun, Panama [RESEARCH ARTICLE]
Daniel Escobar-Camacho, Michele E. R. Pierotti, Victoria Ferenc, Diana M. T Sharpe, Erica Ramos, Cesar Martins, and Karen L. Carleton An adaptive visual system is essential for organisms inhabiting new or changing light environments. The Panama Canal exhibits such variable environments due to its anthropogenic origin and current human activities. Within the Panama Canal, Lake Gatun harbours several exotic fish species including the invasive peacock bass (Cichla monoculus, Agassiz, 1831), a predatory Amazonian cichlid. In this research, through spectral measurements and molecular and physiological experiments, we studied th...
Source: Journal of Experimental Biology - February 20, 2019 Category: Biology Authors: Escobar-Camacho, D., Pierotti, M. E. R., Ferenc, V., Sharpe, D. M. T., Ramos, E., Martins, C., Carleton, K. L. Tags: RESEARCH ARTICLE Source Type: research

The implications of time on the ground on running economy: less is not always better [RESEARCH ARTICLE]
Thibault Lussiana, Aurelien Patoz, Cyrille Gindre, Laurent Mourot, and Kim Hebert-Losier A lower duty factor (DF) reflects a greater relative contribution of leg swing to ground contact time during the running step. Increasing time on the ground has been reported in the scientific literature to both increase and decrease the energy cost (EC) of running, with DF reported to be highly variable in runners. As increasing running speed aligns running kinematics more closely with spring-mass model behaviors and re-use of elastic energy, we compared the centre of mass (COM) displacement and EC between runners with a low (DFlow) a...
Source: Journal of Experimental Biology - February 20, 2019 Category: Biology Authors: Lussiana, T., Patoz, A., Gindre, C., Mourot, L., Hebert-Losier, K. Tags: RESEARCH ARTICLE Source Type: research

Energetics of migratory bats during stopover: a test of the torpor-assisted migration hypothesis [RESEARCH ARTICLE]
This study provides support for the torpor-assisted migration hypothesis, and furthers our understanding of the energy budgets of migratory bats. (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 20, 2019 Category: Biology Authors: Baloun, D. E., Guglielmo, C. G. Tags: RESEARCH ARTICLE Source Type: research

Does the left aorta provide proton-rich blood to the gut when crocodilians digest a meal? [SHORT COMMUNICATION]
Justin L. Conner, Janna L. Crossley, Ruth Elsey, Derek Nelson, Tobias Wang, and Dane A. Crossley II Reptiles have the capacity to differentially perfuse the systemic and pulmonary vascular circuits via autonomic regulation of the heart and the vascular trees. While this aptitude is widely recognized, the role of "shunting" as a homeostatic mechanism to match convective transport with tissue demand remains unknown. In crocodilians, it has been hypothesized that a pulmonary vascular bypass of systemic venous blood, a right-to-left shunt (R-L), serves to deliver CO2-rich blood with protons needed for gastric acid se...
Source: Journal of Experimental Biology - February 20, 2019 Category: Biology Authors: Conner, J. L., Crossley, J. L., Elsey, R., Nelson, D., Wang, T., Crossley, D. A. Tags: SHORT COMMUNICATION Source Type: research

Speed control and force-vectoring of bluebottle flies in a magnetically levitated flight mill [RESEARCH ARTICLE]
Shih-Jung Hsu, Neel Thakur, and Bo Cheng Flies fly at a broad range of speeds and produce sophisticated aerial maneuvers with precisely controlled wing movements. Remarkably, only subtle changes in wing motion are used by flies to produce aerial maneuvers, resulting in little directional tilt of the aerodynamic force vector relative to the body. Therefore, it is often considered that flies fly according to a helicopter model and control speed mainly via force vectoring by body pitch change. Here, we examined the speed control of bluebottle flies using a magnetically levitated (MAGLEV) flight mill, as they fly at different...
Source: Journal of Experimental Biology - February 19, 2019 Category: Biology Authors: Hsu, S.-J., Thakur, N., Cheng, B. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

Hunting great white sharks could motor but prefer to mosey [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 18, 2019 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Complementary roles of photoperiod and temperature in environmental sex determination in Daphnia spp. [RESEARCH ARTICLE]
Allison A. Camp, Maher H. Haeba, and Gerald A. LeBlanc Daphnia spp., a keystone genus in freshwater lentic habitats, are subject to environmental sex determination wherein environmental conditions dictate offspring sex and whether they reproduce asexually or sexually. The introduction of males into a population denotes the first step in the switch from asexual parthenogenetic reproduction to sexual reproduction. We tested the hypothesis that photoperiod and temperature co-regulate male sex determination and that these environmental stimuli would activate elements of the male sex determination signaling cascade. The result...
Source: Journal of Experimental Biology - February 18, 2019 Category: Biology Authors: Camp, A. A., Haeba, M. H., LeBlanc, G. A. Tags: RESEARCH ARTICLE Source Type: research

Contrasting response of haematological variables between long-term training and short exercise bouts in zebra finches (Taeniopygia guttata) [RESEARCH ARTICLE]
Agata Bury, Jowita Niedojadlo, Edyta T. Sadowska, Ulf Bauchinger, and Mariusz Cichon Physical aerobic activity is oxygen demanding, but – particularly for birds – there is still little understanding of how blood contributes to oxygen supply under various activity levels. In a two-factorial experimental design, we investigated the long-term effect of daily flight training and the immediate effect of a short exercise bout on a set of haematological variables: haemoglobin (Hb) content, haematocrit (Hct), and red blood cell number (RBCcount) and size (RBCarea) in zebra finches (Taeniopygia guttata). For a period o...
Source: Journal of Experimental Biology - February 18, 2019 Category: Biology Authors: Bury, A., Niedojadlo, J., Sadowska, E. T., Bauchinger, U., Cichon, M. Tags: RESEARCH ARTICLE Source Type: research

Field-based hearing measurements of two seabird species [METHODS AND TECHNIQUES]
T. Aran Mooney, Adam Smith, Ole Naesbye Larsen, Kirstin Anderson Hansen, Magnus Wahlberg, and Marianne H. Rasmussen Hearing is a primary sensory modality for birds. For seabirds, auditory data is challenging to obtain and hearing data are limited. Here, we present methods to measure seabird hearing in the field, using two Alcid species: the common murre Uria aalge and the Atlantic puffin Fratercula arctica. Tests were conducted in a portable semi-anechoic crate using physiological auditory evoked potential (AEP) methods. The crate and AEP system were easily transportable to northern Iceland field sites, where wild birds w...
Source: Journal of Experimental Biology - February 18, 2019 Category: Biology Authors: Mooney, T. A., Smith, A., Larsen, O. N., Hansen, K. A., Wahlberg, M., Rasmussen, M. H. Tags: METHODS AND TECHNIQUES Source Type: research

Swimming strategies and energetics of endothermic white sharks during foraging [RESEARCH ARTICLE]
Yuuki Y. Watanabe, Nicholas L. Payne, Jayson M. Semmens, Andrew Fox, and Charlie Huveneers Some fishes and sea turtles are distinct from ectotherms by having elevated core body temperatures and metabolic rates. Quantifying the energetics and activity of the regionally endothermic species will help us understand how a fundamental biophysical process (i.e. temperature-dependent metabolism) shapes animal ecology; however, such information is limited owing to difficulties in studying these large, highly active animals. White sharks, Carcharodon carcharias, are the largest fish with regional endothermy, and potentially among t...
Source: Journal of Experimental Biology - February 18, 2019 Category: Biology Authors: Watanabe, Y. Y., Payne, N. L., Semmens, J. M., Fox, A., Huveneers, C. Tags: RESEARCH ARTICLE Source Type: research

How moles destroy your lawn: the forelimb kinematics of eastern moles in loose and compact substrates [RESEARCH ARTICLE]
Yi-Fen Lin, Nicolai Konow, and Elizabeth R. Dumont The interplay between morphological specialization and kinematic flexibility is important for organisms that move between habitats within different substrates. Burrowing is energetically expensive and requires substantial interaction with soil to dislodge and transport it. True moles (Talpidae) have extraordinary forelimb morphologies and a unique ability to dig in loose as well as compact soils, yet we know little of how moles coordinate their forelimb joint kinematics when digging in soils of different compactness. Using marker-based X-ray Reconstruction of Moving Morph...
Source: Journal of Experimental Biology - February 18, 2019 Category: Biology Authors: Lin, Y.-F., Konow, N., Dumont, E. R. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

Skate eyes adapt subtly to see but not be seen [INSIDE JEB]
Casey Gilman (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 15, 2019 Category: Biology Authors: Gilman, C. Tags: INSIDE JEB Source Type: research

Elaborate pupils in skates may help camouflage the eye [SHORT COMMUNICATION]
Sean Youn, Corey Okinaka, and Lydia M. Mäthger The skate Leucoraja erinacea is a bottom-dweller that buries into the substrate with its eyes protruding, revealing elaborately shaped pupils. It has been suggested that such pupil shapes may camouflage the eye, yet this has never been tested. Here, we asked whether skate pupils dilate or constrict depending on background spatial frequency. In experiment 1, the skates' pupillary response to three artificial checkerboards of different spatial frequencies was recorded. Results showed that pupils did not change in response to spatial frequency. In experiment 2, in which skates...
Source: Journal of Experimental Biology - February 15, 2019 Category: Biology Authors: Youn, S., Okinaka, C., Mäthger, L. M. Tags: SHORT COMMUNICATION Source Type: research

Population history with invasive predators predicts innate immune function response to early-life glucocorticoid exposure in lizards [RESEARCH ARTICLE]
Gail L. McCormick, Travis R. Robbins, Sonia A. Cavigelli, and Tracy Langkilde Early-life stress can suppress immune function, but it is unclear whether transgenerational stress exposure modulates the immune consequences of early stress. In populations where, historically, the immune system is frequently activated, e.g. persistent stressors that cause injury, it may be maladaptive to suppress immune function after early-life stress. Thus, the relationship between early-life stress and immune function may vary with population-level historical stressor exposure. We collected gravid fence lizards (Sceloporus undulatus) from p...
Source: Journal of Experimental Biology - February 15, 2019 Category: Biology Authors: McCormick, G. L., Robbins, T. R., Cavigelli, S. A., Langkilde, T. Tags: RESEARCH ARTICLE Source Type: research

Immune challenge-induced oxidative damage may be mitigated by biliverdin [RESEARCH ARTICLE]
Jessica L. Baylor and Michael W. Butler An effective immune response results in the elimination of pathogens, but this immunological benefit may be accompanied by increased levels of oxidative damage. However, organisms have evolved mechanisms to mitigate the extent of such oxidative damage, including the production and mobilization of antioxidants. One potential mechanism of mitigating immune-challenge-induced changes in oxidative physiology is increasing biliverdin production. Biliverdin is chemically an antioxidant, but within-tissue correlations between biliverdin concentration and oxidative damage have never been dire...
Source: Journal of Experimental Biology - February 15, 2019 Category: Biology Authors: Baylor, J. L., Butler, M. W. Tags: RESEARCH ARTICLE Source Type: research

Zonation of Ca2+ transport and enzyme activity in the caeca of rainbow trout - a simple structure with complex functions [RESEARCH ARTICLE]
Melanie Williams, Domenico Barranca, and Carol Bucking Trout caeca are vermiform structures projecting from the anterior intestine of the gastrointestinal tract. Despite their simple gross morphology, these appendages are physically distinct along the anterior-posterior axis and ultrastructural evidence suggests zonation of function within the structures. Individual caeca from three sections (anterior, middle, posterior) were removed from the intestine of freshwater rainbow trout and investigated for ion transport and enzyme activity. Ca2+ absorption appeared as a combination of active and passive movement, with Michaelis-...
Source: Journal of Experimental Biology - February 14, 2019 Category: Biology Authors: Williams, M., Barranca, D., Bucking, C. Tags: RESEARCH ARTICLE Source Type: research

A tale of two genes: divergent evolutionary fate of haptoglobin and hemopexin in hemoglobinless antarctic icefishes [RESEARCH ARTICLE]
Kevin T. Bilyk, Xuan Zhuang, Katherine R. Murphy, and C-H. Christina Cheng Evolution of Antarctic notothenioid fishes in the isolated freezing Southern Ocean have led to remarkable trait gains and losses. One of the most extraordinary was the loss of the major oxygen carrier hemoglobin (Hb) in the icefishes (family Channichthyidae). While the mechanisms of this loss and the resulting compensatory changes have been well studied, the impact of Hb loss on the network of genes that once supported its recycling and disposal has remained unexplored. Here we report the functional fate and underlying molecular changes of two such ...
Source: Journal of Experimental Biology - February 14, 2019 Category: Biology Authors: Bilyk, K. T., Zhuang, X., Murphy, K. R., Cheng, C.-H. C. Tags: RESEARCH ARTICLE Source Type: research

Ventilation and gas exchange before and after voluntary static surface breath-holds in clinically healthy bottlenose dolphins, Tursiops truncatus [RESEARCH ARTICLE]
A. Fahlman, M. Brodsky, S. Miedler, S. Dennison, M. Ivancic, G. Levine, J. Rocho-Levine, M. Manley, J. Rocabert, and A. Borque Espinosa We measured respiratory flow (V), breathing frequency (fR), tidal volume (VT), breath durations, and end-expired O2 content in bottlenose dolphins (Tursiops truncatus) before and after static surface breath-holds ranging from 34 to 292 s. There was considerable variation in the end-expired O2, tidal volume VT, and fR following a breath-hold. The analysis suggests that the dolphins attempt to minimize recovery following a dive by altering VT, and fR to rapidly restore the O2 stores. For the...
Source: Journal of Experimental Biology - February 13, 2019 Category: Biology Authors: Fahlman, A., Brodsky, M., Miedler, S., Dennison, S., Ivancic, M., Levine, G., Rocho-Levine, J., Manley, M., Rocabert, J., Borque Espinosa, A. Tags: RESEARCH ARTICLE Source Type: research

Symmetry breaking and pivotal individuals during the reunification of ant colonies [RESEARCH ARTICLE]
In this study, we found that colonies can reunify even without obvious cues to break the symmetry between sites. To learn how they do so, we observed both symmetric reunifications (between identical nests) and asymmetric reunifications (between nests of unequal quality) by colonies of individually-marked ants. Both reunification types were accomplished by a tiny minority that carried nestmates from the ‘losing’ to the ‘winning’ site. Reunification effort was highly skewed in asymmetric splits, where the majority of the work was done by the first ant to transport, who nearly always came from the winn...
Source: Journal of Experimental Biology - February 13, 2019 Category: Biology Authors: Doering, G. N., Pratt, S. C. Tags: RESEARCH ARTICLE Source Type: research

Autonomic control of cardiovascular adjustments associated with orthostasis in the scansorial snake Boa constrictor [RESEARCH ARTICLE]
Vinicius Araujo Armelin, Victor Hugo da Silva Braga, Igor Noll Guagnoni, Ariela Maltarolo Crestani, Augusto Shinya Abe, and Luiz Henrique Florindo Orthostatic hypotension is a phenomenon triggered by a change in the position or posture of an animal, from a horizontal to a vertical head-up orientation, characterised by a blood pooling in the lower body and a reduction in central and cranial arterial blood pressure (PA). This hypotension elicits systemic vasoconstriction and tachycardia, which generally reduce blood pooling and increase PA. Little is known about the mediation and importance of such cardiovascular adjustments...
Source: Journal of Experimental Biology - February 13, 2019 Category: Biology Authors: Armelin, V. A., Braga, V. H. d. S., Guagnoni, I. N., Crestani, A. M., Abe, A. S., Florindo, L. H. Tags: RESEARCH ARTICLE Source Type: research

Development of a deep neural network for automated electromyographic pattern classification [METHODS [amp ] TECHNIQUES]
Riad Akhundov, David J. Saxby, Suzi Edwards, Suzanne Snodgrass, Phil Clausen, and Laura E. Diamond Determining the signal quality of surface electromyography (sEMG) recordings is time consuming and requires the judgment of trained observers. An automated procedure to evaluate sEMG quality would streamline data processing and reduce time demands. This paper compares the performance of two supervised and three unsupervised artificial neural networks (ANNs) in evaluation of sEMG quality. Manually classified sEMG recordings from various lower-limb muscles during motor tasks were used to train (n=28000), test performance (n=120...
Source: Journal of Experimental Biology - February 13, 2019 Category: Biology Authors: Akhundov, R., Saxby, D. J., Edwards, S., Snodgrass, S., Clausen, P., Diamond, L. E. Tags: METHODS [amp ] TECHNIQUES Source Type: research

Bee and floral traits affect the characteristics of the vibrations experienced by flowers during buzz-pollination [RESEARCH ARTICLE]
Blanca Arroyo-Correa, Ceit Beattie, and Mario Vallejo-Marin During buzz pollination, bees use their indirect flight muscles to produce vibrations that are transmitted to the flowers and result in pollen release. Although buzz pollination has been known for>100 years, we are still in the early stages of understanding how bee and floral characteristics affect the production and transmission of floral vibrations. Here we analysed floral vibrations produced by four closely related bumblebee taxa (Bombus spp.) on two buzz-pollinated plants species (Solanum spp.). We measured floral vibrations transmitted to the flower to est...
Source: Journal of Experimental Biology - February 13, 2019 Category: Biology Authors: Arroyo-Correa, B., Beattie, C., Vallejo-Marin, M. Tags: RESEARCH ARTICLE Source Type: research

Dynamics of blood circulation during diving in the bottlenose dolphin (Tursiops truncatus). The role of the retia mirabilia [RESEARCH ARTICLE]
Marco Bonato, Paola Bagnoli, Cinzia Centelleghe, Mike Maric, Ginevra Brocca, Sandro Mazzariol, and Bruno Cozzi The retia mirabilia are vascular nets composed by small vessels dispersed among numerous veins, allowing blood storage, regulation of flow, and pressure damping effects. Here we investigated their potential role during the diving phase of the bottlenose dolphin (Tursiops truncatus). To this effect, the whole vertebral retia mirabilia of a series of dolphins were removed during post-mortem analysis and examined to assess vessel diameters, estimate vascular volume, and flow rate. Here we formulate a new hemodynamic ...
Source: Journal of Experimental Biology - February 13, 2019 Category: Biology Authors: Bonato, M., Bagnoli, P., Centelleghe, C., Maric, M., Brocca, G., Mazzariol, S., Cozzi, B. Tags: RESEARCH ARTICLE Source Type: research

Food deprivation reduces social interest in the European sea bass Dicentrarchus labrax [RESEARCH ARTICLE]
This study examined to what extent food deprivation modulates fish risk-taking and social behaviours, as well as the relationship between them. To address these issues, juvenile European sea bass were either fed daily with a maintenance ration or food deprived for a period of 3 weeks. Risk taking and sociability were assessed through measurements of fish willingness to explore a novel environment, and to interact with a novel object or a conspecific. Multivariate analysis allowed the identification of three behaviours: risk taking, exploratory activity and solitariness. Food-deprived fish interacted less with conspeci...
Source: Journal of Experimental Biology - February 12, 2019 Category: Biology Authors: Aimon, C., Le Bayon, N., Le Floch, S., Claireaux, G. Tags: RESEARCH ARTICLE Source Type: research

Returning chum salmon shift metabolism to cope with different river temperatures [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 11, 2019 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Spittlebugs snorkel in cuckoo spit [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 11, 2019 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Facultative mobilization of eggshell calcium promotes embryonic growth in an oviparous snake [RESEARCH ARTICLE]
James R. Stewart, Rebecca A. Pyles, Kaitlyn A. Mathis, and Tom W. Ecay The mineralized eggshell of Reptilia was a major innovation in the evolution of the amniotic egg. Inorganic components strengthen the eggshell and are a potential source of nutrients to developing embryos. Embryos of oviparous reptiles do extract calcium from eggshells but vary interspecifically in exploitation of this resource. The pattern of embryonic calcium nutrition of the corn snake, Pantherophis guttatus, is similar to a diversity of squamate species: embryos obtain most calcium from yolk, yet also mobilize calcium from the eggshell. We tested t...
Source: Journal of Experimental Biology - February 11, 2019 Category: Biology Authors: Stewart, J. R., Pyles, R. A., Mathis, K. A., Ecay, T. W. Tags: RESEARCH ARTICLE Source Type: research

Studies on gas exchange in the meadow spittlebug, Philaenus spumarius: the metabolic cost of feeding on, and living in, xylem sap [RESEARCH ARTICLE]
Kephra I. S. Beckett, Anne B. Robertson, and Philip G. D. Matthews Spittlebugs (superfamily Cercopoidea) live within a mass of frothy, spittle-like foam that is produced as a by-product of their xylem-feeding habits. The wet spittle represents a unique respiratory environment for an insect, potentially acting either as a reserve of trapped oxygen (O2) or as a significant barrier to O2 diffusion from the surrounding atmosphere. Feeding on xylem sap under tension is also assumed to be energetically expensive, potentially placing further constraints on their gas exchange. To understand the respiratory strategies used by spit...
Source: Journal of Experimental Biology - February 11, 2019 Category: Biology Authors: Beckett, K. I. S., Robertson, A. B., Matthews, P. G. D. Tags: RESEARCH ARTICLE Source Type: research

Alanine, proline and urea are major organic osmolytes in the snail Theodoxus fluviatilis under hyperosmotic stress [RESEARCH ARTICLE]
Amanda A. Wiesenthal, Christian Müller, Katrin Harder, and Jan-Peter Hildebrandt Hyperosmotic stress may result in osmotic volume loss from the body to the environment in animals that cannot control the water permeability of their integument. Euryhaline animals (which have a wide tolerance range of environmental salinities) have generally evolved the ability to counteract cell volume shrinkage by accumulating inorganic and organic osmolytes within their cells to balance internal and external osmolalities. Molluscs use very different combinations of amino acids and amino acid derivatives to achieve this goal. Theodoxus f...
Source: Journal of Experimental Biology - February 8, 2019 Category: Biology Authors: Wiesenthal, A. A., Müller, C., Harder, K., Hildebrandt, J.-P. Tags: RESEARCH ARTICLE Source Type: research

Starvation resistance is associated with developmentally specified changes in sleep, feeding and metabolic rate [RESEARCH ARTICLE]
Elizabeth B. Brown, Melissa E. Slocumb, Milan Szuperak, Arianna Kerbs, Allen G. Gibbs, Matthew S. Kayser, and Alex C. Keene Food shortage represents a primary challenge to survival, and animals have adapted diverse developmental, physiological and behavioral strategies to survive when food becomes unavailable. Starvation resistance is strongly influenced by ecological and evolutionary history, yet the genetic basis for the evolution of starvation resistance remains poorly understood. The fruit fly Drosophila melanogaster provides a powerful model for leveraging experimental evolution to investigate traits associated with ...
Source: Journal of Experimental Biology - February 8, 2019 Category: Biology Authors: Brown, E. B., Slocumb, M. E., Szuperak, M., Kerbs, A., Gibbs, A. G., Kayser, M. S., Keene, A. C. Tags: RESEARCH ARTICLE Source Type: research

Neuroligin tuning of pharyngeal pumping reveals extrapharyngeal modulation of feeding in Caenorhabditis elegans [RESEARCH ARTICLE]
Fernando Calahorro, Francesca Keefe, James Dillon, Lindy Holden-Dye, and Vincent O'Connor The integration of distinct sensory modalities is essential for behavioural decision making. In Caenorhabditis elegans, this process is coordinated by neural circuits that integrate sensory cues from the environment to generate an appropriate behaviour at the appropriate output muscles. Food is a multimodal cue that impacts the microcircuits to modulate feeding and foraging drivers at the level of the pharyngeal and body wall muscle, respectively. When food triggers an upregulation in pharyngeal pumping, it allows the effective inges...
Source: Journal of Experimental Biology - February 8, 2019 Category: Biology Authors: Calahorro, F., Keefe, F., Dillon, J., Holden-Dye, L., O'Connor, V. Tags: RESEARCH ARTICLE Source Type: research

Bone without minerals and its secondary mineralization in Atlantic salmon (Salmo salar): the recovery from phosphorus deficiency [RESEARCH ARTICLE]
This study used a P-deficient salmon model to falsify three hypotheses. First, an extended period of dietary P deficiency does not cause pathologies other than osteomalacia. Second, secondary mineralization of non-mineralized bone is possible. Third, secondary mineralization can restore the bones' mineral composition and mechanical properties. For 7 weeks, post-smolt Atlantic salmon (Salmo salar) received diets with regular P content (RP) or with a 50% lowered P content (LP). For additional 9 weeks, RP animals continued on the regular diet (RP-RP). LP animals continued on the LP diet (LP-LP), on a regular P diet ...
Source: Journal of Experimental Biology - February 8, 2019 Category: Biology Authors: Witten, P. E., Fjelldal, P. G., Huysseune, A., McGurk, C., Obach, A., Owen, M. A. G. Tags: RESEARCH ARTICLE Source Type: research

Correction: New approaches for assessing squid fin motions: coupling proper orthogonal decomposition with volumetric particle tracking velocimetry (doi:10.1242/jeb.176750) [CORRECTION]
Ian K. Bartol, Paul S. Krueger, Carly A. York, and Joseph T. Thompson (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 7, 2019 Category: Biology Authors: Bartol, I. K., Krueger, P. S., York, C. A., Thompson, J. T. Tags: CORRECTION Source Type: research