The impact of the gut microbiome on memory and sleep in Drosophila [RESEARCH ARTICLE]
Valeria Silva, Angelina Palacios-Munoz, Zeynep Okray, Karen L. Adair, Scott Waddell, Angela E. Douglas, and John Ewer
The gut microbiome has been proposed to influence diverse behavioral traits of animals, although the experimental evidence is limited and often contradictory. Here, we made use of the tractability of Drosophila melanogaster for both behavioral analyses and microbiome studies to test how elimination of microorganisms affects a number of behavioral traits. Relative to conventional flies (i.e. with unaltered microbiome), microbiologically sterile (axenic) flies displayed a moderate reduction in memory perform...
Source: Journal of Experimental Biology - February 5, 2021 Category: Biology Authors: Silva, V., Palacios-Munoz, A., Okray, Z., Adair, K. L., Waddell, S., Douglas, A. E., Ewer, J. Tags: RESEARCH ARTICLE Source Type: research
Ocean acidification alters properties of the exoskeleton in adult Tanner crabs, Chionoecetes bairdi [RESEARCH ARTICLE]
Gary H. Dickinson, Shai Bejerano, Trina Salvador, Christine Makdisi, Shrey Patel, W. Christopher Long, Katherine M. Swiney, Robert J. Foy, Brittan V. Steffel, Kathryn E. Smith, and Richard B. Aronson
Ocean acidification can affect the ability of calcifying organisms to build and maintain mineralized tissue. In decapod crustaceans, the exoskeleton is a multilayered structure composed of chitin, protein and mineral, predominately magnesian calcite or amorphous calcium carbonate (ACC). We investigated the effects of acidification on the exoskeleton of mature (post-terminal-molt) female southern Tanner crabs, Chionoecetes bai...
Source: Journal of Experimental Biology - February 5, 2021 Category: Biology Authors: Dickinson, G. H., Bejerano, S., Salvador, T., Makdisi, C., Patel, S., Long, W. C., Swiney, K. M., Foy, R. J., Steffel, B. V., Smith, K. E., Aronson, R. B. Tags: RESEARCH ARTICLE Source Type: research
Innovation in solitary bees is driven by exploration, shyness and activity levels [RESEARCH ARTICLE]
Miguel A. Collado, Randolf Menzel, Daniel Sol, and Ignasi Bartomeus
Behavioural innovation and problem solving are widely considered to be important mechanisms by which animals respond to novel environmental challenges, including those induced by human activities. Despite their functional and ecological relevance, much of our current understanding of these processes comes from studies in vertebrates. Understanding of these processes in invertebrates has lagged behind partly because they are not perceived to have the cognitive machinery required. This perception is, however, challenged by recent evidence demonstrating soph...
Source: Journal of Experimental Biology - February 5, 2021 Category: Biology Authors: Collado, M. A., Menzel, R., Sol, D., Bartomeus, I. Tags: RESEARCH ARTICLE Source Type: research
Plasticity in parental effects confers rapid larval thermal tolerance in the estuarine anemone Nematostella vectensis [Research Article]
Hanny E. Rivera, Cheng-Yi Chen, Matthew C. Gibson, and Ann M. Tarrant Parental effects can prepare offspring for different environments and facilitate survival across generations. We exposed parental populations of the estuarine anemone, Nematostella vectensis, from Massachusetts to elevated temperatures and quantified larval mortality across a temperature gradient. We find that parental exposure to elevated temperatures results in a consistent increase in larval thermal tolerance, as measured by the temperature at which 50% of larvae die (LT50), with a mean increase in LT50 of 0.3°C. Larvae from subsequent spawns retu...
Source: Journal of Experimental Biology - February 5, 2021 Category: Biology Authors: Rivera, H. E., Chen, C.-Y., Gibson, M. C., Tarrant, A. M. Tags: Research Article Source Type: research
Epicatechin increases the persistence of long-term memory formed by conditioned taste aversion in Lymnaea [SHORT COMMUNICATION]
We examined the effects of epicatechin (Epi), a flavonoid abundant in green tea and cocoa, on long-term memory (LTM) formed following conditioned taste aversion (CTA) training in Lymnaea stagnalis. In CTA training, the snails learnt to avoid a food that initially they liked (i.e. sucrose). Twenty-four hours after CTA training, 67% of the trained snails showed a significant decrease in the feeding behaviour elicited by sucrose. Placing snails in the Epi solution in CTA training did not alter the percentage of snails exhibiting LTM, but it significantly increased LTM persistence. We also examined changes following Epi exposu...
Source: Journal of Experimental Biology - February 4, 2021 Category: Biology Authors: Itoh, A., Komatsuzaki, Y., Lukowiak, K., Saito, M. Tags: SHORT COMMUNICATION Source Type: research
Contrasting strategies of osmotic and ionic regulation in freshwater crabs and shrimps: gene expression of gill ion transporters [RESEARCH ARTICLE]
Milene Mantovani and John Campbell McNamara
Owing to their extraordinary niche diversity, the Crustacea are ideal for comprehending the evolution of osmoregulation. The processes that effect systemic hydro-electrolytic homeostasis maintain hemolymph ionic composition via membrane transporters located in highly specialized gill ionocytes. We evaluated physiological and molecular hyper- and hypo-osmoregulatory mechanisms in two phylogenetically distant, freshwater crustaceans, the crab Dilocarcinus pagei and the shrimp Macrobrachium jelskii, when osmotically challenged for up to 10 days. When in distilled water, D. pag...
Source: Journal of Experimental Biology - February 4, 2021 Category: Biology Authors: Mantovani, M., McNamara, J. C. Tags: RESEARCH ARTICLE Source Type: research
Do aquatic ectotherms perform better under hypoxia after warm acclimation? [REVIEW]
Michael Collins, Manuela Truebano, Wilco C. E. P. Verberk, and John I. Spicer
Aquatic animals increasingly encounter environmental hypoxia due to climate-related warming and/or eutrophication. Although acute warming typically reduces performance under hypoxia, the ability of organisms to modulate hypoxic performance via thermal acclimation is less understood. Here, we review the literature and ask whether hypoxic performance of aquatic ectotherms improves following warm acclimation. Interpretation of thermal acclimation effects is limited by reliance on data from experiments that are not designed to directly test for bene...
Source: Journal of Experimental Biology - February 4, 2021 Category: Biology Authors: Collins, M., Truebano, M., Verberk, W. C. E. P., Spicer, J. I. Tags: Ecophysiology: responses to environmental stressors and change REVIEW Source Type: research
Latency of mechanically stimulated escape responses in the Pacific spiny dogfish, Squalus suckleyi [SHORT COMMUNICATION]
Mathias Schakmann, Victoria Becker, Mathias Sogaard, Jacob L. Johansen, John F. Steffensen, and Paolo Domenici
Fast escape responses to a predator threat are fundamental to the survival of mobile marine organisms. However, elasmobranchs are often underrepresented in such studies. Here, we measured the escape latency (time interval between the stimulus and first visible reaction) of mechanically induced escape responses in the Pacific spiny dogfish, Squalus suckleyi, and in two teleosts from the same region, the great sculpin, Myoxocephalus polyacanthocephalus, and the pile perch, Rhacochilus vacca. We found that the dogfi...
Source: Journal of Experimental Biology - February 4, 2021 Category: Biology Authors: Schakmann, M., Becker, V., Sogaard, M., Johansen, J. L., Steffensen, J. F., Domenici, P. Tags: SHORT COMMUNICATION Source Type: research
Response of the copepod Acartia tonsa to the hydrodynamic cues of small-scale, dissipative eddies in turbulence [RESEARCH ARTICLE]
This study quantifies the behavioral response of a marine copepod (Acartia tonsa) to individual, small-scale, dissipative vortices that are ubiquitous in turbulence. Vortex structures were created in the laboratory using a physical model of a Burgers vortex with characteristics corresponding to typical dissipative vortices that copepods are likely to encounter in the turbulent cascade. To examine the directional response of copepods, vortices were generated with the vortex axis aligned in either the horizontal or vertical direction. Tomographic particle image velocimetry was used to measure the volumetric velocity field of...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Elmi, D., Webster, D. R., Fields, D. M. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research
Rapid and parallel changes in activity and mRNA of intestinal peptidase to match altered dietary protein levels in juvenile house sparrows (Passer domesticus) [RESEARCH ARTICLE]
Antonio Brun, Melisa E. Magallanes, William H. Karasov, and Enrique Caviedes-Vidal
Although dietary flexibility in digestive enzyme activity (i.e. reaction rate) is widespread in vertebrates, mechanisms are poorly understood. When laboratory rats are switched to a higher protein diet, the activities of apical intestinal peptidases increase within 15 h, in some cases by rapid increase in enzyme transcription followed by rapid translation and translocation to the intestine's apical, brush-border membrane (BBM). Focusing on aminopeptidase-N (APN), we studied intestinal digestive enzyme flexibility in birds, relying on a...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Brun, A., Magallanes, M. E., Karasov, W. H., Caviedes-Vidal, E. Tags: RESEARCH ARTICLE Source Type: research
Do endotherms have thermal performance curves? [COMMENTARY]
Danielle L. Levesque and Katie E. Marshall
Temperature is an important environmental factor governing the ability of organisms to grow, survive and reproduce. Thermal performance curves (TPCs), with some caveats, are useful for charting the relationship between body temperature and some measure of performance in ectotherms, and provide a standardized set of characteristics for interspecific comparisons. Endotherms, however, have a more complicated relationship with environmental temperature, as endothermy leads to a decoupling of body temperature from external temperature through use of metabolic heat production, large ch...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Levesque, D. L., Marshall, K. E. Tags: COMMENTARY Source Type: research
Continuous body 3-D reconstruction of limbless animals [METHODS [amp ] TECHNIQUES]
Qiyuan Fu, Thomas W. Mitchel, Jin Seob Kim, Gregory S. Chirikjian, and Chen Li Limbless animals such as snakes, limbless lizards, worms, eels, and lampreys move their slender, long body in three dimensions to traverse diverse environments. Accurately quantifying their continuous body's 3-D shape and motion is important for understanding body-environment interaction in complex terrain, but this is difficult to achieve (especially for local orientation and rotation). Here, we describe an interpolation method to quantify continuous body 3-D position and orientation. We simplify the body as an elastic rod and apply a backbone ...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Fu, Q., Mitchel, T. W., Kim, J. S., Chirikjian, G. S., Li, C. Tags: METHODS [amp ] TECHNIQUES Source Type: research
Testing the influence of crushing-surface variation on seed cracking performance between beak morphs of the African seedcracker Pyrenestes ostrinus [RESEARCH ARTICLE]
Nicola S. Heckeberg, Philip S. L. Anderson, and Emily J. Rayfield Extreme phenotypic polymorphism is an oft-cited example of evolutionary theory in practise. Although these morphological variations are assumed to be adaptive, few studies have biomechanically tested such hypotheses. Pyrenestes ostrinus (the African seedcracker finch) shows an intraspecific polymorphism in beak size and shape that is entirely diet driven and allelically determined. Three distinct morphs feed upon soft sedge seeds during times of abundance, but switch to specializing on three different species of sedge seeds that differ significantly in hardn...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Heckeberg, N. S., Anderson, P. S. L., Rayfield, E. J. Tags: RESEARCH ARTICLE Source Type: research
Olfactory tracking strategies in a Neotropical fruit bat [RESEARCH ARTICLE]
Alyson F. Brokaw and Michael Smotherman Many studies have characterized olfactory-tracking behaviors in animals, and it has been proposed that search strategies may be generalizable across a wide range of species. Olfaction is important for fruit and nectar feeding bats, but it is uncertain if existing olfactory search models can predict the strategies of flying mammals that emit echolocation pulses through their nose. Quantitative assessments of how well echolocating bats track and localize odor sources are lacking, so we developed a behavioral assay to characterize the olfactory detection and tracking behavior of crawlin...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Brokaw, A. F., Smotherman, M. Tags: RESEARCH ARTICLE Source Type: research
Improving spring-mass parameter estimation in running using nonlinear regression methods [RESEARCH ARTICLE]
We present a method to model runners as spring-mass systems using nonlinear regression (NLR) and the full vertical ground reaction force (vGRF) time series without additional inputs and fewer traditional parameter assumptions. We derived and validated a time-dependent vGRF function characterized by four spring-mass parameters–stiffness, touchdown angle, leg length, and contact time–using a sinusoidal approximation. Next, we compared the NLR-estimated spring-mass parameters to traditional calculations in runners. The mixed-effect NLR method (ME NLR) modeled the observed vGRF best (RMSE:155 N) compared to a conve...
Source: Journal of Experimental Biology - February 3, 2021 Category: Biology Authors: Burns, G. T., Gonzalez, R., Zernicke, R. F. Tags: RESEARCH ARTICLE Source Type: research
