Thresholds of polarization vision in octopus [RESEARCH ARTICLE]
In this study, the ability of octopus to detect polarization contrasts varying in angle of polarization (AoP) was investigated over a range of different degrees of linear polarization (DoLP) to better judge their visual ability in more ecologically relevant conditions. The ‘just-noticeable-differences’ (JND) of AoP contrasts varied consistently with DoLP. These JND thresholds could be largely explained by their polarization distance, a neurophysical model that effectively calculates the level of activity in opposing horizontally and vertically oriented polarization channels in the cephalopod visual system. Imag...
Source: Journal of Experimental Biology - February 18, 2021 Category: Biology Authors: Temple, S. E., How, M. J., Powell, S. B., Gruev, V., Marshall, N. J., Roberts, N. W. Tags: RESEARCH ARTICLE Source Type: research
Transgenic expression of late embryogenesis abundant proteins improves tolerance to water stress in Drosophila melanogaster [RESEARCH ARTICLE]
In conclusion, the gain of function studies reported here show that LEA proteins can improve tolerance to water stress in a desiccation-sensitive species that normally lacks these proteins, and, simultaneously, underscore the complexity of desiccation tolerance across multiple life stages in multicellular organisms. (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 16, 2021 Category: Biology Authors: Anderson, J. M., Hand, S. C. Tags: RESEARCH ARTICLE Source Type: research
Effects of variable oxygen regimes on mitochondrial bioenergetics and reactive oxygen species production in a marine bivalve, Mya arenaria [RESEARCH ARTICLE]
Natascha Ouillon, Eugene P. Sokolov, Stefan Otto, Gregor Rehder, and Inna M. Sokolova
Estuarine and coastal benthic organisms often experience fluctuations in oxygen levels that can negatively impact their mitochondrial function and aerobic metabolism. To study these impacts, we exposed a common sediment-dwelling bivalve, the soft-shell clam Mya arenaria, for 21 days to chronic hypoxia (PO2 ~4.1 kPa), cyclic hypoxia (PO2 ~12.7–1.9 kPa, mean 5.7 kPa) or normoxia (PO2 ~21.1 kPa). pH was manipulated to mimic the covariation in CO2/pH and oxygen levels in coastal hypoxic zones. Mi...
Source: Journal of Experimental Biology - February 16, 2021 Category: Biology Authors: Ouillon, N., Sokolov, E. P., Otto, S., Rehder, G., Sokolova, I. M. Tags: RESEARCH ARTICLE Source Type: research
Analysis of why sea turtles swim slowly: a metabolic and mechanical approach [RESEARCH ARTICLE]
This study measured the resting metabolic rates and drag coefficients of sea turtles to answer two questions: (1) do turtles swim at the optimal swim speed?; and (2) what factors control the optimal swim speed of turtles? The resting metabolic rates of 13 loggerhead and 12 green turtles were measured; then, the cruising swim speeds of 15 loggerhead and 9 green turtles were measured and their drag coefficients were estimated under natural conditions. The measured cruising swim speeds (0.27–0.50 m s–1) agreed with predicted optimal swim speeds (0.19–0.32 m s–1). The resting metabolic rates o...
Source: Journal of Experimental Biology - February 16, 2021 Category: Biology Authors: Kinoshita, C., Fukuoka, T., Narazaki, T., Niizuma, Y., Sato, K. Tags: RESEARCH ARTICLE Source Type: research
Acclimation of intestinal morphology and function in Djungarian hamsters (Phodopus sungorus) related to seasonal and acute energy balance [RESEARCH ARTICLE]
This study investigated whether seasonal or acute acclimation to anticipated or actual energetic challenges in Djungarian hamsters also resulted in higher nutrient resorption capacities owing to changes in small intestine histology and physiology. The hamsters show numerous seasonal energy-saving adjustments in response to short photoperiod. As spontaneous daily torpor represents one of these adjustments related to food quality and quantity, it was hypothesized that the hamsters' variable torpor expression patterns are influenced by their individual nutrient uptake capacity. Hamsters under short photoperiod showed longer s...
Source: Journal of Experimental Biology - February 16, 2021 Category: Biology Authors: Piscitiello, E., Herwig, A., Haugg, E., Schröder, B., Breves, G., Steinlechner, S., Diedrich, V. Tags: RESEARCH ARTICLE Source Type: research
Effects of early-life exposure to sublethal levels of a common neonicotinoid insecticide on the orientation and migration of monarch butterflies (Danaus plexippus) [RESEARCH ARTICLE]
Alana A. E. Wilcox, Amy E. M. Newman, Nigel E. Raine, Greg W. Mitchell, and D. Ryan Norris
Migratory insects use a variety of innate mechanisms to determine their orientation and maintain correct bearing. For long-distance migrants, such as the monarch butterfly (Danaus plexippus), these journeys could be affected by exposure to environmental contaminants. Neonicotinoids are synthetic insecticides that work by affecting the nervous system of insects, resulting in impairment of their mobility, cognitive performance, and other physiological and behavioural functions. To examine how neonicotinoids might affect the ability of...
Source: Journal of Experimental Biology - February 15, 2021 Category: Biology Authors: Wilcox, A. A. E., Newman, A. E. M., Raine, N. E., Mitchell, G. W., Norris, D. R. Tags: RESEARCH ARTICLE Source Type: research
Warm fish eggs gasp for oxygen [OUTSIDE JEB]
Till Harter (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 12, 2021 Category: Biology Authors: Harter, T. Tags: OUTSIDE JEB Source Type: research
Mole-rats play evolution by ear [OUTSIDE JEB]
Brittney G. Borowiec (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 12, 2021 Category: Biology Authors: Borowiec, B. G. Tags: OUTSIDE JEB Source Type: research
Panting zebra finches twitter to keep cool [OUTSIDE JEB]
Ana Breit (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 12, 2021 Category: Biology Authors: Breit, A. Tags: OUTSIDE JEB Source Type: research
Synthetic sunflower scent trains bees for better pollination [OUTSIDE JEB]
Ravindra Palavalli-Nettimi (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 12, 2021 Category: Biology Authors: Palavalli-Nettimi, R. Tags: OUTSIDE JEB Source Type: research
Gusty winds, flappy wings [OUTSIDE JEB]
Jan Stenum (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 12, 2021 Category: Biology Authors: Stenum, J. Tags: OUTSIDE JEB Source Type: research
Does the preferred walk-run transition speed on steep inclines minimize energetic cost, heart rate or neither? [RESEARCH ARTICLE]
Jackson W. Brill and Rodger Kram
As walking speed increases, humans choose to transition to a running gait at their preferred transition speed (PTS). Near that speed, it becomes metabolically cheaper to run rather than to walk and that defines the energetically optimal transition speed (EOTS). Our goals were to determine: (1) how PTS and EOTS compare across a wide range of inclines and (2) whether the EOTS can be predicted by the heart rate optimal transition speed (HROTS). Ten healthy, high-caliber, male trail/mountain runners participated. On day 1, subjects completed 0 and 15 deg trials and on day 2, they complete...
Source: Journal of Experimental Biology - February 12, 2021 Category: Biology Authors: Brill, J. W., Kram, R. Tags: RESEARCH ARTICLE Source Type: research
Head bobbing gives pigeons a sense of perspective [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - February 10, 2021 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research
Physiology and behavior under food limitation support an escape, not preparative, response in the nomadic pine siskin (Spinus pinus) [RESEARCH ARTICLE]
Joely G. DeSimone, Bret W. Tobalske, and Creagh W. Breuner
Migration allows animals to use resources that are variable in time and/or space, with different migratory strategies depending on the predictability of resource variation. When food varies seasonally, obligate migrants anticipate and prepare for migration. In contrast, facultative migrants, whose movements are unpredictable in timing and destination, may prepare for either migration or escape when resources are depleted. We propose and test two alternative hypotheses regarding the behavioral and physiological responses of facultative migrants to declining food av...
Source: Journal of Experimental Biology - February 10, 2021 Category: Biology Authors: DeSimone, J. G., Tobalske, B. W., Breuner, C. W. Tags: RESEARCH ARTICLE Source Type: research
Multisensory integration supports configural learning of a home refuge in the whip spider Phrynus marginemaculatus [RESEARCH ARTICLE]
Kaylyn A. S. Flanigan, Daniel D. Wiegmann, Eileen A. Hebets, and Verner P. Bingman
Whip spiders (Amblypygi) reside in structurally complex habitats and are nocturnally active yet display notable navigational abilities. From the theory that uncertainty in sensory inputs should promote multisensory representations to guide behavior, we hypothesized that their navigation is supported by a multisensory and perhaps configural representation of navigational inputs, an ability documented in a few insects and never reported in arachnids. We trained Phrynus marginemaculatus to recognize a home shelter characterized by both discrim...
Source: Journal of Experimental Biology - February 10, 2021 Category: Biology Authors: Flanigan, K. A. S., Wiegmann, D. D., Hebets, E. A., Bingman, V. P. Tags: RESEARCH ARTICLE Source Type: research
