Controlled expression of the migratory phenotype affects oxidative status in birds [RESEARCH ARTICLE]
We examined whether the emergence of the migratory phenotype, primarily signaled by increased food intake and fuelling, is accompanied by changes in oxidative status. We induced autumn migration followed by a non-migratory wintering phase in Common quails (Coturnix coturnix). We compared three markers of oxidative status: oxidative damage to lipids expressed as Thiobarbituric Acid Reactive Substances (TBARS); superoxide dismutase (SOD); and glutathione peroxidase (GPx) between birds sampled during the migratory- and non-migratory phase. We found that the emergence of the migratory phenotype was associated with: (i) higher ...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Marasco, V., Sebastiano, M., Costantini, D., Pola, G., Fusani, L. Tags: RESEARCH ARTICLE Source Type: research
Effect of density and species preferences on collective choices: an experimental study on maggot aggregation behaviours [RESEARCH ARTICLE]
This study was designed to (1) assess the collective behaviours of blow fly larvae (Diptera: Calliphoridae) in groups varying in density and species composition, and (2) to relate them to the costs and benefits of aggregating on fresh or decomposed food. First, experiments testing conspecific groups of Lucilia sericata and Calliphora vicina larvae, two species feeding at the same time on fresh carcasses, demonstrated decreases in growth and survival on rotten beef liver compared to fresh liver. However, mixing species together reduced this adverse impact of decomposition by increasing the mass of emerged adults. Second, la...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Fouche, Q., Hedouin, V., Charabidze, D. Tags: RESEARCH ARTICLE Source Type: research
Rhythmic auditory stimuli modulates movement recovery to perturbation during locomotion [METHODS [amp ] TECHNIQUES]
Deepak K. Ravi, Marc Bartholet, Andreas Skiadopoulos, Jenny A. Kent, Jordan Wickstrom, William R. Taylor, Navrag B. Singh, and Nick Stergiou The capacity to recover after a perturbation is a well-known intrinsic property of physiological systems, including the locomotor system, and can be termed resilience. Despite an abundance of metrics proposed to measure the complex dynamics of bipedal locomotion, analytical tools for quantifying resilience are lacking. Here, we introduce a novel method to directly quantify resilience to perturbations during locomotion. We examine the extent to which synchronizing stepping with two dif...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Ravi, D. K., Bartholet, M., Skiadopoulos, A., Kent, J. A., Wickstrom, J., Taylor, W. R., Singh, N. B., Stergiou, N. Tags: METHODS [amp ] TECHNIQUES Source Type: research
Feel the light - sight independent negative phototactic response in octopus' arms [RESEARCH ARTICLE]
Itamar Katz, Tal Shomrat, and Nir Nesher Controlling the octopus's flexible hyper-redundant body is a challenging task. It is assumed that the octopus has poor proprioception which has driven the development of unique mechanisms for efficient body control. Here we report on such a mechanism, a phototactic response of extraocular photoreception. Extraocular photoreception has been observed in many and diverse species. Previous research on cephalopods revealed that increased illumination on their skin evokes chromatophore expansion. Recently, the mechanism was investigated and has been termed 'light-activated chromatophore e...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Katz, I., Shomrat, T., Nesher, N. Tags: RESEARCH ARTICLE Source Type: research
Attack behaviour in naïve Gyrfalcons is modelled by the same guidance law as in Peregrines, but at a lower guidance gain [RESEARCH ARTICLE]
Caroline H. Brighton, Katherine E. Chapman, Nicholas C. Fox, and Graham K. Taylor The aerial hunting behaviours of birds are strongly influenced by flight morphology and ecology, but little is known of how this relates to the behavioural algorithms guiding flight. Here we use GPS loggers to record the attack trajectories of captive-bred Gyrfalcons (Falco rusticolus) during their maiden flights against robotic aerial targets, which we compare to existing flight data from Peregrines (Falco peregrinus). The attack trajectories of both species are well modelled by a proportional navigation (PN) guidance law, which commands tur...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Brighton, C. H., Chapman, K. E., Fox, N. C., Taylor, G. K. Tags: RESEARCH ARTICLE Source Type: research
Temperature adaptations of the thermophilic snail Echinolittorina malaccana: insights from metabolomic analysis [RESEARCH ARTICLE]
Ya-qi Chen, Jie Wang, Ming-ling Liao, Xiao-xu Li, and Yun-wei Dong The periwinkle snail Echinolittorina malaccana, whose upper lethal temperature is near 55°C, is one of the most heat-tolerant eukaryotes known. We conducted a multi-level investigation, including cardiac physiology, enzyme activity, and targeted and untargeted metabolomic analysis, that elucidated a spectrum of adaptations to extreme heat. All systems examined showed heat intensity-dependent responses. Under moderate heat stress (from 37 to 45°C) the snail depressed cardiac activity and entered a state of metabolic depression. The global metabolomic...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Chen, Y.-q., Wang, J., Liao, M.-l., Li, X.-x., Dong, Y.-w. Tags: RESEARCH ARTICLE Source Type: research
High carbohydrate diet ingestion increases post-meal lipid synthesis and drives respiratory exchange ratios above 1 [SHORT COMMUNICATION]
S. Talal, A. Cease, R. Farington, H. E. Medina, J. Rojas, and J. Harrison Locusts have been reported to elevate metabolic rate in response to high carbohydrate diets; this conclusion was based on metabolic rates calculated from CO2 production, a common practice for insects. However, respiratory exchange ratios (RER, CO2 production divided by O2 consumption) can rise above 1 due to de novo lipid synthesis, providing an alternate possible explanation of the prior findings. We studied the relationship between macronutrient ingestion, RER, and lipid synthesis using South American locusts (Schistocerca cancellata) reared on art...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Talal, S., Cease, A., Farington, R., Medina, H. E., Rojas, J., Harrison, J. Tags: SHORT COMMUNICATION Source Type: research
Aversive operant conditioning alters the phototactic orientation of the marbled crayfish [RESEARCH ARTICLE]
Shione Okada, Natsumi Hirano, Toshiki Abe, and Toshiki Nagayama Aversive learning was applied to affect the phototactic behaviour of the marbled crayfish. Animals initially showed negative phototaxis to white light and positive taxis to blue light. Using an aversive learning paradigm, we investigated the plasticity of innate behaviour following operant conditioning. The initial rate of choosing a blue-lit exit was analysed by a dual choice experiment between blue-lit and white-lit exits in pre-test conditions. During training, electrical shocks were applied to the animals when they oriented to the blue-lit exit. Memory tes...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Okada, S., Hirano, N., Abe, T., Nagayama, T. Tags: RESEARCH ARTICLE Source Type: research
Accounting for body mass effects in the estimation of field metabolic rates from body acceleration [RESEARCH ARTICLE]
Evan E. Byrnes, Karissa O. Lear, Lauran R. Brewster, Nicholas M. Whitney, Matthew J. Smukall, Nicola J. Armstrong, and Adrian C. Gleiss Dynamic Body Acceleration (DBA), measured through animal-attached tags, has emerged as a powerful method for estimating field metabolic rates of free-ranging individuals. Following respirometry to calibrate oxygen consumption rate (MO2) with DBA under controlled conditions, predictive models can be applied to DBA data collected from free-ranging individuals. However, laboratory calibrations are generally performed on a relatively narrow size range of animals, which may introduce biases if ...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Byrnes, E. E., Lear, K. O., Brewster, L. R., Whitney, N. M., Smukall, M. J., Armstrong, N. J., Gleiss, A. C. Tags: RESEARCH ARTICLE Source Type: research
Maternal provisioning and fluctuating thermal regimes enhance immune response in a reptile with temperature-dependent sex determination [RESEARCH ARTICLE]
Jessica Alice Leivesley and Njal Rollinson The Charnov-Bull model of differential fitness is often used to explain the evolution and maintenance of temperature-dependent sex determination (TSD). Most tests of the model focus on morphological proxies of fitness, such as size traits, whereas early life physiological traits that are closely related to lifetime fitness might provide a framework for generalising the Charnov-Bull model across taxa. One such trait is the strength of early life immune response, which is strongly linked to early life survival and fitness. Here, we manipulate temperature, variance in temperature, an...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Leivesley, J. A., Rollinson, N. Tags: RESEARCH ARTICLE Source Type: research
Miraculous skin metamorphosis for beached amphibious fish [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 2, 2021 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research
Lower-limb muscle function is influenced by changing mechanical demands in cycling [RESEARCH ARTICLE]
We examined whether muscle function was sensitive to these changes in mechanical demands across a wide range of pedalling conditions. We collected experimental data of cycling where crank torque and pedalling cadence were independently varied from 13 to 44 N m and 60 to 140 rpm. These data were used in conjunction with musculoskeletal simulations and a recently developed functional index-based approach to characterise the role of human lower-limb muscles. We found that in muscles that generate most of the mechanical power and work during cycling, greater crank torque induced shifts towards greater muscle act...
Source: Journal of Experimental Biology - February 2, 2021 Category: Biology Authors: Lai, A. K. M., Dick, T. J. M., Brown, N. A. T., Biewener, A. A., Wakeling, J. M. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research
Estimation of sinking velocity using free-falling dynamically scaled models: Foraminifera as a test case [METHODS [amp ] TECHNIQUES]
Matthew Walker, Jörg U. Hammel, Fabian Wilde, Tatjana Hoehfurtner, Stuart Humphries, and Rudi Schuech
The velocity of settling particles is an important determinant of distribution in extinct and extant species with passive dispersal mechanisms, such as plants, corals and phytoplankton. Here, we adapted dynamic scaling, borrowed from engineering, to determine settling velocity. Dynamic scaling leverages physical models with relevant dimensionless numbers matched to achieve similar dynamics to the original object. Previous studies have used flumes, wind tunnels or towed models to examine fluid flow around objects w...
Source: Journal of Experimental Biology - February 1, 2021 Category: Biology Authors: Walker, M., Hammel, J. U., Wilde, F., Hoehfurtner, T., Humphries, S., Schuech, R. Tags: METHODS [amp ] TECHNIQUES Source Type: research
Different protein metabolic strategies for growth during food-induced physiological plasticity [RESEARCH ARTICLE]
Aimee Ellison, Amara Pouv, and Douglas A. Pace Food-induced morphological plasticity, a type of developmental plasticity, is a well-documented phenomenon in larvae of the echinoid echinoderm, Dendraster excentricus. A recent study in our lab has shown that this morphological plasticity is associated with significant physiological plasticity for growth. The goal of the current study was to measure several aspects of protein metabolism in larvae growing at different rates to understand the mechanistic basis for this physiological growth plasticity. Larvae of D. excentricus were fed rations of 1,000 (low-fed) or 10,000 (high-...
Source: Journal of Experimental Biology - February 1, 2021 Category: Biology Authors: Ellison, A., Pouv, A., Pace, D. A. Tags: RESEARCH ARTICLE Source Type: research
Cutaneous tactile sensitivity before and after tail loss and regeneration in the leopard gecko (Eublepharis macularius) [RESEARCH ARTICLE]
Stefanie S. Bradley, Erika Howe, Leah R. Bent, and Matthew K. Vickaryous Amongst tetrapods, mechanoreceptors on the feet establish a sense of body placement and help to facilitate posture and biomechanics. Mechanoreceptors are necessary for stabilizing the body while navigating through changing terrains or responding to a sudden change in body mass and orientation. Lizards such as the leopard gecko (Eublepharis macularius) employ autotomy – a voluntary detachment of a portion of the tail, to escape predation. Tail autotomy represents a natural form of significant (and localized) mass loss. Semmes-Weinstein monofilame...
Source: Journal of Experimental Biology - February 1, 2021 Category: Biology Authors: Bradley, S. S., Howe, E., Bent, L. R., Vickaryous, M. K. Tags: RESEARCH ARTICLE Source Type: research
