Integrative and Comparative Biology最新文献

Wildlife health comparisons within and across populations and species are essential for population assessment and surveillance of emerging infectious diseases. Due to low costs and high informational yield, hematology is commonly used in the fields of ecoimmunology and disease ecology, yet consistency and proper reporting of methods within these fields are lacking. Previous investigations on various wildlife taxa have revealed noteworthy impacts of the vein used for blood collection on hematology measures. However, the impacts of venipuncture site on bats, a taxon of increasing interest in ecoimmunology and disease ecology, have not yet been tested. Here, we use a long-term study system in western Oklahoma to test the effect of venipuncture site on hematology parameters of the Mexican free-tailed bat (Tadarida brasiliensis) and cave myotis (Myotis velifer), two abundant and representative bat species from the families Molossidae and Vespertilionidae. Between September 2023 and October 2024, we collected paired peripheral blood from both the propatagial and intrafemoral veins in 25 individuals per species. We then quantified total red and white blood cells, reticulocyte counts, and leukocyte differentials and used generalized linear mixed models to compare parameters among venipuncture sites within and between bat species. Overall, venipuncture site had no effect on any hematology parameters; however, we revealed small differences in neutrophil and lymphocyte proportions between veins among the species. By contrast, we detected significant species-level differences in most cell measurements, which we propose could be explained by life-history strategy and phylogenetic differences. We encourage continued testing of additional venipuncture sites, and of the same venipuncture sites on different species, on hematology and other health metrics used in ecoimmunology and disease ecology. Lastly, we emphasize the importance of thorough method reporting in publications to enable transparent comparisons and accounting for even small sampling-based artifacts. All future efforts are especially important for bats to improve conservation monitoring, ecosystem services estimations, and their association with emerging infectious diseases.

Biological segmented armors integrate mineralized tiles with soft tissues, forming a structure that is both puncture resistant and flexible. In the 9-banded armadillo Dasypus novemcinctus, scapular and pelvic buckler osteoderm tiles are hexagonally shaped, tapering from the superficial face down to the deep face. Each osteoderm is embedded in the dermis and adjacent osteoderms are connected to one another via connective Sharpey's fibers. Our study hierarchically investigated the relationship between armor geometry, connective fibers, and soft supporting layers during flexion. We used micro-CT scans to inform the design of simplified 3D-printed buckler osteoderm models with 3 taper angles, 2 types of connective layers of different compliances (elastic and rigid), and one soft silicone rubber layer. Resistance to bending for 18 model combinations were tested using a 3-point bend test. We found that tapered tiles form a "sweet spot" between flexibility and rigidity. Tapered geometry decreased the stiffness of the system, while models without tapers greatly increased the stiffness via increased tile interactions. The stiff fabric set a limit for bending, regardless of taper type, and there was no additive effect when combining stiff and elastic fabrics. The silicone rubber increased the flexural stiffness of the model and helped to redistribute forces. This study further demonstrates that armadillo armor is complex and relies on hard-soft interfaces to resist bending and to translocate damaging forces. When creating bio-inspired models, it is imperative to take biological complexity into account, yet test the system hierarchically to better predict the role of the geometry as well as the material (hard and soft elements).

The inherent benefits of soft materials in robotic designs have rendered soft robotics a growing field in research and engineering. Due to their compliance, soft robots are safe in working environments shared with humans, offer great potential in health care and medical applications, and may be operational in environments inaccessible or unfit for their solid body counterparts. However, for truly soft, self-contained robots, onboard electronics-free control is required. While there are pneumatic transistors that can be combined to simple control logics, the weight of these circuits may sometimes overburden soft-legged robots. To overcome the weight limitation of our current soft robotic prototypes, we sought inspiration from nature by studying the leg morphology and parasagittal gait of mammals. They have been shaped by evolution to support the heaviest terrestrial animals on earth: elephants. We assume that the leg morphology and strides of elephants are optimized for energy efficiency and/or load bearing, and we translated their characteristics to a pneumatically actuated elephant soft robotic leg. However, as soft actuators are remarkably different from the mammal joint-and-muscle system, a direct transfer from joint angles and muscle movement is not desirable. We therefore adapted the known kinematics of elephant strides to PneuNet bending actuators by means of approximating the actuators' bending angles to elephants' joint angles and subsequently arranging different actuator states into a sequence in order to approximate the elephant strides. We here present our current version of a biomimetic soft walker with parasagittal gait achieving a speed of 126 mm/s (0.82 body lengths per second) and a total load capacity of >5.2 × its body weight.

During swallowing, a diverse range of mammals-from opossums to humans-propel food boluses out of the oropharynx via tongue base retraction (TBR). The widespread distribution of TBR behavior implies an ancient evolutionary origin, but the biomechanical mechanisms of TBR remain poorly understood. The evolution of TBR behavior is further complicated by the diversity of hyoid and tongue anatomy across mammals: to what extent does hyolingual morphology shape TBR mechanism? Using biplanar videoradiography and the XROMM workflow, we collected high-resolution 3D kinematic data in opossums (Marsupialia), dogs (Placentalia), and macaques (Placentalia) to test hypotheses on the evolutionary conservation of TBR mechanisms. Despite differences in hyolingual morphology and resting hyoid position, both dogs and macaques drive TBR through hyoid movement: hyoid excursions reduce the oral volume and squeeze the tongue base posteriorly, analogous to a hydraulic pump displacing an incompressible fluid. In opossums, however, intrinsic lingual muscles deform the tongue base to initiate TBR, independent of hyoid movement and oral volume change. We suggest that multiple mechanisms are viable for the highly conserved TBR behavior across mammals, and the functional diversity of TBR mechanisms is decoupled from the morphological diversity of the hyolingual system. This decoupling may have facilitated the evolution of novel hyolingual phenotypes while avoiding trade-offs in swallowing performance.

Bio-inspired design has become a significant driver of innovation, enabling the development of effective solutions to some of the world's toughest challenges. Bio-inspired design leverages evolutionary advancements to create products and processes that are often more efficient and sustainable. However, applying biological insights to engineering can be challenging due to the distinct ways the two disciplines define and interpret core concepts. This paper explores the cognitive and technical skills required to effectively translate biological inspiration into engineering solutions. Our hypothesis focuses on bridging the "language and representation gap" between biology and engineering. The goal of this paper is to identify key aspects of biological representation that enable its successful adaptation into engineering design, fostering the development of more impactful and efficient bio-inspired solutions. The analysis of student feedback and ideation outputs revealed that engineers preferred biology texts with a medium level of technical complexity, balancing ease of understanding with image quantity. Basic references were found to support diverse idea generation, while more technical texts proved useful and necessary for understanding in-depth biological insights and applying them to engineering problems. Future research could explore the impact of information presentation order, the role of biological experts in deepening insights, and the use of machine learning to refine how biological information is selected and categorized to enhance the bio-inspired design process.

Amphibians, like other vertebrates, respond to stressors through the activation of the hypothalamic-pituitary-interrenal (HPI) axis, leading to elevated levels of glucocorticoids in the bloodstream. The amphibian HPI axis is functionally analogous to the mammalian hypothalamic-pituitary-adrenal (HPA) axis, coordinating the stress response via glucocorticoid release. Among these, corticosterone (CORT) acts as the principal downstream effector hormone, exerting widespread effects on various physiological systems. As seen in many other vertebrates, physiologically increased CORT levels are commonly associated with immune modulation, which might enhance or suppress the immune response. This immune outcome is influenced by several factors, including the duration and intensity of the stressors, the body condition of individuals, life history, and species-specific traits. Here, we provide a literature review on the role of stressors and CORT in amphibian immunity, including studies conducted in natural environments and controlled settings. These studies involve standardized stress protocols (i.e., restraint, captivity, and exogenous hormone treatment), along with "in vivo" and "in vitro" immune assays. Overall, CORT levels and their effects on immunity are highly variable, yet they do not act in isolation. There is significant interaction between CORT and other hormones, such as testosterone and melatonin, which further influences the immune response in amphibians. This interplay underscores the complexity of the stress-immune relationship and suggests that a holistic approach is essential to fully understand the impact of stressors on amphibian health and conservation.

We present a portable, noninvasive, and low-cost three-dimensional tracking method to quantify in situ water-hopping kinematics of mudskippers. By combining dual-camera video recordings with tracking the fish path, Gaussian Splatting terrain reconstruction and stereo matching, we capture detailed 3D trajectories of mudskippers in their natural tidal-flat habitats. Our proposed method resolves hopping motions including both straight and curved escape paths, and reveals that horizontal stride length, hopping height, and velocity are strongly influenced by fish length and local terrain features. These results highlight both the biomechanical and ecological significance of water-hopping in mudskippers, demonstrating how a simple, deployable 3D approach can resolve complex amphibious movements in challenging field environments.

African Americans are still underrepresented in science, technology, engineering, and math (STEM) careers. This fact has had profoundly negative impacts on both the lives and fortunes of African Americans, as well as our society as a whole. This pattern of underrepresentation does not result from an inherent mental deficiency or lack of interest in science by African Americans. Rather, this results from historical and ongoing discrimination against this group throughout American society. This paper recounts this discrimination in the context of society as a whole and higher education with a specific emphasis on STEM careers in biology and organismal biology in particular. It offers concrete recommendations for changing the enterprise of science such that it can foster greater inclusion of African Americans via the support for and expansion of the capacity of Historically Black Universities and Colleges (HBCUs).

Mobulas (manta and devil rays) are large-scale ram filter feeders that separate planktonic food particles from large volumes of water with minimal clogging. This contrasts with most human-made filters that can suffer from problematic clogging requiring additional mechanisms for clearing blocked surfaces and maintaining performance. Prior studies have shown that mobulas employ a unique mechanism referred to as ricochet separation to filter feed, whereby captive vortices in filter pores cause particles to bounce off the filter surfaces and away from the filter pores. This mechanism enables the filtration of particles smaller than the pore size and reduced clogging. However, few studies have examined how the morphology of the filtering structure varies across the diversity of mobulid species, and little is known about how this variation may impact filtration efficiency or prey selectivity. This study conducts a systematic investigation of the gross morphology of the filtering structure in seven mobilid species using a combination of computed tomography and macro photography. Examination of filter anatomy suggests that some features are highly variable while others are well-conserved across species. In particular, a reconstruction of the phylogenetically corrected morphospaces indicated that the primary pore dimensions of the filter lobes are a major driver of morphological variation across species. Additionally, inspection of the gross anatomy revealed a pronounced asymmetry in the anterior and posterior filter plates of each gill arch. This asymmetry suggests that water may impinge on the filtering structures at different angles than has previously been speculated. Here, the functional ramifications of the observed morphological variations were interpreted using recent modeling studies. Most mobulid fishes have a filter morphology that should be capable of high filtration efficiency and low hydrodynamic resistance, but may also be sensitive to flow conditions. A deeper understanding of the mechanics of filter-feeding in mobulid fishes would generate needed insights into the ecology of these species and could provide a firmer framework for the development of bioinspired filtration systems. These findings highlight the value of integrating detailed anatomical studies into bioinspired design efforts and pave the way for the development of bioinspired filter systems with improved performance.

The tongue plays a crucial role in feeding by positioning, manipulating, and transporting the bolus during chewing and swallowing. As a muscular hydrostat, its biomechanical function relies on regional deformations and coordinated movements with the jaw. Sensory feedback from oral afferents, particularly via the trigeminal nerve, is critical for modulating these movements and deformations. This study investigates how food texture and oral sensory perturbations influence tongue kinematics in an omnivorous carnivoran, the skunk (Mephitis mephitis). Using X-ray Reconstruction of Moving Morphology (XROMM) and controlled nerve blocks to the tongue and teeth, we analyzed tongue protraction-retraction, regional lengthening-shortening, and their timing relative to the gape cycle across three foods-banana, carrot, and kibble. Results indicate that food properties significantly impact tongue movements, with soft foods like banana eliciting greater anteroposterior motion and posterior tongue deformation. Despite these kinematic differences, the timing of tongue movements relative to jaw cycles remains consistent, but there are differences in the timing of regional lengthening and shortening between foods. Bilateral nerve blocks altered tongue kinematics and deformations, particularly regional deformations, but did not disrupt overall coordination with the chewing cycle. These findings suggest that oral afferents refine motor commands, optimizing tongue-bolus interactions while rhythmic jaw-tongue coordination patterns are maintained. This study enhances our understanding of sensorimotor integration in mammalian feeding and provides insights on tongue biomechanics as a muscular hydrostat.