Vaughanwollesen3681

© 2020. Published by The Company of Biologists Ltd.Social insect societies are characterized by division of labour and communication within the colony. The most frequent mode of communication is by chemical signals. In general, pheromones elicit specific responses in the receiver, although reactions may vary depending on the receiving individual's physiological or motivational state. For example, it has been shown that pheromones can elicit different responses in morphological worker castes. However, comparably little is known about such effects in worker castes of monomorphic species. Here, we comprehensively studied a monomorphic species showing age polyethism, the thelytokous ant Platythyrea punctata Our analyses revealed that the species' alarm pheromone consists of (S)-(-)-citronellal and (S)-(-)-actinidine, and is produced in the mandibular glands. Ants responded with increased movement activity and increasing ant density towards the pheromone source in whole-colony bioassays, confirming the alarming effect of these compounds. We found age classes to differ in their absolute pheromone content, in the propensity to release alarm pheromone upon disturbance and in their reaction towards the pheromone. Absolute amounts of pheromone content may differ simply because the biosynthesis of the pheromone begins only after adult eclosion. Nonetheless, our results indicate that this clonal species exhibits age-related polyethism in the emission of as well as in the response to its alarm pheromone. © 2020. Published by The Company of Biologists Ltd.A considerable body of work has examined the dynamics of different dog gaits, but there are no studies that focused on limb dynamics in jumping. Jumping is an essential part of dog agility, a dog sport in which handlers direct their dogs through an obstacle course in a limited time. We hypothesized that limb parameters like limb length and stiffness indicate the skill level of dogs. We analyzed global limb parameters in jumping for 10 advanced and 10 beginner dogs. In experiments, we collected 3D kinematics and ground reaction forces during dog jumping at high forward speeds. Our results revealed general strategies of limb control in jumping and highlighted differences between advanced and beginner dogs. In take-off, the spatially leading forelimb was 75% (p less then 0.001) stiffer than the trailing forelimb. In landing, the trailing forelimb was 14% stiffer (p less then 0.001) than the leading forelimb. This indicates a strut-like action of the forelimbs to achieve jumping height in take-off and to transfer vertical velocity into horizontal velocity in landing (with switching roles of the forelimbs). During landing, the more (24%) compliant forelimbs of beginner dogs (p=0.005), resulted in 17% (p=0.017) higher limb compression during the stance phase. This is associated with a larger amount of eccentric muscle contraction, which might in turn explain the soft tissue injuries that frequently occur in the shoulder region of beginner dogs. For all limbs, length at toe-off was greater for advanced dogs. Hence, limb length and stiffness might be used as objective measures of skill. © 2020. Published by The Company of Biologists Ltd.Phenotypic flexibility may facilitate range expansion by allowing organisms to maintain high levels of performance when introduced to novel environments. Phenotypic flexibility, such as reversible acclimatization, permits organisms to achieve high performance over a wide range of environmental conditions, without the costly allocation or acquisition tradeoffs associated with behavioral thermoregulation, which may expedite range expansions in introduced species. Selleckchem Nintedanib The northern curly-tailed lizard, Leiocephalus carinatus, was introduced to the United States in the 1940s and is now established in southern Florida. We measured bite force and the thermal sensitivity of sprinting of L. carinatus during the winter and spring to determine how morphology and performance varied seasonally. We found evidence of seasonal variation in several aspects of physiological performance. Lizards sampled in spring sprinted faster and tolerated higher temperatures, while lizards sampled in winter had high performance over a wider range of temperatures. Furthermore, seasonal differences in physiology were only detected after generating thermal reaction norms. Both sprint and bite force performance did not differ seasonally when solely comparing performance at a common temperature. No seasonal relationships between morphology and performance were detected. Our results suggest that L. carinatus may use reversible acclimatization to maintain high levels of performance across seasons not typically experienced within their native range. Thermal physiology plasticity may ameliorate the impacts of sub-optimal temperatures on performance without the cost of behavioral thermoregulation. Our work highlights the importance of utilizing reaction norms when evaluating performance and the potential ecological impacts of introduced species. © 2020. Published by The Company of Biologists Ltd.The equine microbiome can change in response to dietary alteration and might play a role in insulin dysregulation. The aim of this study was to determine the effect of adding pasture to a hay diet on the fecal bacterial microbiome of both healthy and insulin-dysregulated ponies. Fecal samples were collected from sixteen ponies before and after dietary change to enable bacterial 16S rRNA sequencing of the V3-V4 region. The dominant phyla in all samples were the Firmicutes and Bacteroidetes. The evenness of the bacterial populations decreased after grazing pasture, and when a pony was moderately insulin-dysregulated (P=0.001). Evenness scores negatively correlated with post-prandial glucagon-like peptide-1 concentrations after a hay-only diet (r2;=-0.7, P=0.001). A change in diet explained 3% of fecal microbiome variability. We conclude that metabolically healthy ponies have greater microbial stability when challenged with a subtle dietary change, compared to moderately insulin-dysregulated ponies. © 2020. Published by The Company of Biologists Ltd.