Journal of Experimental Biology最新文献

For nearly a century, scientists have tried to resolve the sensory physiology of chemical communication caused by predation stress. Only recently have we evidenced that abiotic stressors from a changing world, such as heat and ocean acidification, also trigger chemical communication between aquatic organisms - which we dubbed abiotic stress communication. Generally, the behavioural and physiological response to stress-induced cues are well understood, whereas the molecular mechanisms - cue identities, pathways of release, and perception - of this stress communication remain unresolved. Here, we propose a framework to organize the existing evidence for candidate mechanisms involved in abiotic stress-induced chemical communication, focusing on heat and acidification as two major abiotic stressors with environmental relevance. Drawing on transcriptomic, metabolomic and behavioural evidence, we propose that stressor-specific communication likely involves multiple cues and parallel routes rather than a single mechanism, such as membrane-related processes. We call for integrative work that links -omics with chemical profiling and ecological function assays to uncover the mechanisms of abiotic stress communication.

To understand how fish use vision to navigate, we must first understand what they see. This Review explores how visually guided navigation in teleost fishes is shaped by the structure of their visual systems, the cognitive processes that interpret sensory input and the dynamic environments they inhabit. With broad variation in habitat, ecology and visual capabilities, fish provide a powerful system for examining how sensory conditions influence navigation. We focus on short-range navigation and review core strategies - beaconing, pilotage, path integration and spatial mapping - alongside the visual and cognitive demands each entails. To assess which strategies are available to different species, we examine the visual processing pathway, from eye and retinal anatomy to behavioural evidence from cognition studies. These reveal that fish process visual information in a variety of ways to perform a diverse range of visual functions, including motion perception, object recognition and generalisation across viewpoint or lighting changes. We consider how sensory limitations and visual noise may constrain navigational accuracy, and how context or visual ability might shape which strategies are used. Environmental changes, such as turbidity, light pollution, or habitat degradation or shifts, can further degrade cue availability and reliability, affecting navigational performance. Understanding how visual information is received, processed and applied is therefore essential not only for interpreting observed behaviours, but also for predicting how fish may respond to changing environments. By linking sensory input with spatial behaviour, we propose a framework that integrates perception, cognition and movement, offering new insight into how diverse visual systems shape navigation across species.

Thermoregulation is an essential fitness-relevant process for nearly all ectothermic animals. Preferred or optimal body temperatures can be achieved through both behavioural and physiological mechanisms and the ecological importance and evolutionary context of these mechanisms have been well studied. Less understood, however, are the mechanisms driving variation in thermoregulatory decisions. With this Commentary, we emphasize the importance of understanding the sensory pathways and processes by which organisms translate information from their environment to thermoregulatory decisions and highlight the lack of essential empirical data in this field. Leveraging the rich literature of thermoregulation in lizards, we first synthesize established mechanisms of both behavioural and physiological thermoregulation. We then describe what is known about the sensory pathways and integration centres of the nervous system that transduce environmental information into thermoregulatory actions, via somatic and autonomic pathways. We provide guidance on how a better integration of sensory biology, endocrinology, animal behaviour and thermal biology will improve our understanding of key aspects of thermoregulation in ectotherms. Finally, we offer future directions to obtain a more cohesive understanding of thermoregulation, especially as cues and information in the environment continue to shift with climate change.

Many different types of insects make seasonal migrations over vast distances, typically from one broad geographical region to another, most often involving a latitudinal change in one direction in spring with a reversal of this direction in autumn. However, a small handful of these species instead migrate from an enormous geographical area to a highly specific destination they have never previously visited, a journey they make only once. Of these, only two - the diurnal monarch butterfly and the nocturnal bogong moth - are well studied. Even though these lepidopterans have sophisticated multisensory compass mechanisms to guide their long journeys, some studies question whether they are capable of navigating to their goal, or whether they just end up there more or less by chance, pushed by the prevailing winds (a 'stochastic wind-borne' transport mechanism). At the other extreme is the possibility that monarch butterflies and bogong moths are 'true navigators', with the ability to directly travel to their distant goal by using a 'compass' to guide them in their inherited migratory direction and a 'map' that continuously updates their current position. In this Review, we will argue that the evidence for stochastic wind-borne transport and true navigation is weak, and that the current weight of evidence supports 'vector navigation'. We present a hypothesis that individual Lepidoptera use vector navigation to migrate to a distant goal by employing favourable winds and global compass mechanisms to choose their desired flight directions during consecutive journey segments (or vectors), each of different length and direction, and with each vector transition being initiated by innate recognition of local sensory cues. We further hypothesise that this recognition is passed on to coming generations via epigenetic memory.

Many aquatic animals have a well-developed sense of hearing as sound is important for communication underwater. However, this trait leaves them susceptible to injury, and physiological and behavioral impacts from exposure to intense or persistent anthropogenic sounds. We provide an overview of the current state of knowledge on the physiological effects of five main sources of anthropogenic sound: marine traffic, seismic exploration, pile driving, other industrial activity and sonar. Our understanding of impacts varies greatly by sound type and taxon, although the studied species do not represent the full taxonomic diversity. Exposure to ship sounds has been best studied in fish and it generally leads to responses along the stress response cascade, while few studies have been conducted on its physiological effect on invertebrates or marine mammals. Effects of exposure to seismic sound show mixed impact across taxa. Pile driving sounds have been shown in captive studies to result in hearing impairment in marine mammals and can cause injury to fishes. Lethal impacts have been documented from naval sonar on marine mammal species. Currently, physiological impacts from other industrial sound sources are poorly documented across taxa. Overall, given the limited number of species examined in sound impact experiments, it is crucial to establish categorizing principles and guidelines and modeled response pathways to improve management strategies, especially as new sound threats continue to emerge in our changing world.

Climate change is threatening global biodiversity as a result of increasing temperature and climate variability outpacing adaptation rates. Ectothermic animals, such as most fishes, are particularly vulnerable to environmental change because their physiology is intimately controlled by their surrounding environment. Importantly, the impact of temperature on animals depends not only on the degree of warming but also on their ability to accurately detect and evade that warming. The first step in this process is the recognition of changes in temperature by integral membrane proteins such as transient receptor potential (TRP) channels, some of which are temperature sensitive (thermoTRPs). Most of our understanding of thermoTRPs comes from studies in mammals, with a dearth of information in ectotherms on thermal sensitivities, and modulation of these thermal sensors. In this Commentary, we highlight what is known about the mechanism of temperature sensing in fishes. We also propose that changes in biological context (e.g. social interactions, lipids and immune state), leading to changes in physiology and behaviour, influence how fish sense temperature, potentially altering thermal susceptibility. Finally, we discuss redundancy in temperature-sensing systems, identify knowledge gaps, and suggest integrative approaches and questions for us to better understand temperature sensing and its modulation in fishes.

Mutualistic interactions between night-blooming flowers and their nocturnal pollinators present unique challenges for both partners. Although most flowering plants and pollinators are diurnal, nocturnal pollination is not uncommon. In dim light conditions, flowers must remain attractive to pollinators, whereas pollinators must detect, discriminate and remember floral cues amid a noisy and variable sensory landscape. Both moths and bats are particularly well known for their roles as nocturnal pollinators. Yet, our understanding of the sensory ecology of these and other lesser-studied nocturnal pollinators remains limited. Little is known about the dependence of their activity and behaviour on daily fluctuations in natural night-time light levels, the circa-monthly lunar cycle, or the sensory adaptations that facilitate pollination. These knowledge gaps are concerning given the global spread of artificial light at night (ALAN), which envelops much of the Earth's surface. Current research on the responses of nocturnal pollinators to ALAN is fragmented, revealing effects that vary by both species and type of lighting. However, the knock-on effects of these responses remain poorly understood. In this Review, I discuss current knowledge and identify critical gaps across four themes, namely: (1) nocturnal pollinator activity in relation to natural ambient light levels and lunar phases; (2) the effects of ALAN on the visual ecology of nocturnal pollinators; (3) the consequences of ALAN for plant-pollinator interactions; and (4) unresolved questions concerning the sensory ecology of nocturnal pollinators and how disruptions may scale to affect broader plant-pollinator dynamics under increasingly illuminated night skies.

Echolocating big brown bats hunt insects flying along unpredictable paths in front of vegetation. We conducted three psychophysical experiments to investigate how these bats alter their spatial attention when localizing virtual target echoes appearing unpredictably in azimuth and against weak physical clutter. Four bats were trained to detect virtual echoes presented from a 120 deg azimuthal array of six loudspeakers. Within a single trial, echoes could remain in the same position or shift unpredictably to a new one. The bats performed well in stationary trials but were less accurate when targets shifted more peripherally and contralaterally to the original azimuth. They aimed their sonar beams accurately at targets appearing centrally; they were less precise but faster when localizing targets in the periphery, maintaining a more central acoustic gaze with only momentary peripheral shifts. When localizing a shifted target, bats reduced the interpulse intervals between broadcasts and emitted proportionally more sonar sound groups, suggesting increased perceived task difficulty. Weak clutter located closely behind the virtual target reduced accuracy in localizing target shifts, affected the speed of beam aim adjustment, and was associated with an increase in broadcast duration. Interpulse intervals and sonar sound groups were not strongly affected by clutter. Behavioral differences between bats showed the impact of individual problem-solving strategies. These findings demonstrate that the distribution of spatial attention is biased towards the center of the ensonified field of view and is influenced by weak background clutter.

Insects rely on sophisticated odor-tracking mechanisms to locate mates and food sources, or follow conspecific trails, in both two (e.g. substrate-based tracking by ants and termites) and three (e.g. airborne pheromone plume tracking by flying insects) dimensions. These behaviors rely on the integration of multisensory information and understanding them requires us to draw upon principles from odor transport physics, odor chemistry and sensory ecology. Airborne odor plumes are typically heterogeneous and turbulent, delivering chemical cues in intermittent bursts, while ground-based odor trails are more stable and localized. Hence, insects employ fundamentally distinct strategies to navigate these environments, shaped by the physical and chemical properties of the odorants. Insect odor-tracking behavior is mediated by an array of sensory modalities, including chemosensory, visual, mechanosensory and thermal inputs. Experimental approaches in both laboratory and field settings have revealed how insects integrate these cues to successfully identify odor sources under complex environmental conditions. Comparative studies, such as those examining diurnal versus nocturnal tracking, highlight how sensory prioritization shifts with ecological context, revealing adaptive neural integration mechanisms. This article reviews the behavioral strategies insects use for odor tracking in air and on the ground, focusing on the role of multisensory integration and the vulnerability of these behaviors to sensory noise. Emerging research on environmental disruptions, such as artificial light at night and air pollution, highlights the ecological threats to odor-mediated behaviors. By synthesizing insights from diverse insect taxa, we examine how sensory noise and anthropogenic change can impair essential behaviors such as foraging and mating.

Sleep serves many functions that enable effective performance of the awake animal. Failure to obtain adequate sleep leads to lapses in motivation, attention and reaction times, coordination, and learning and memory. How do animals living in modified landscapes obtain their daily amount of sleep in the presence of pollution and anthropogenic disturbance? We review a subset of the studies examining if, and how, animals sleep in this disturbed world with a focus on artificial light at night, urban noise, psychoactive pollutants in waterways, agricultural practices, introduced species and a warming world. We highlight gaps in understanding and prescribe areas for future work. Notably, there is limited knowledge on truly wild animals, as well as the functional consequences of disrupted sleep for the efficacy of waking performance, fitness and survival. We close with ideas for mitigation, including tips that are achievable locally, by individuals. Such efforts will make it easier for wildlife to sleep soundly.