Integrative and Comparative Biology最新文献

Over 97% of ray-finned fish produce free-swimming larvae. With survival rates of less than 0.01% and radically different morphologies from adults, fish larvae play a crucial role in adapting to environmental changes and dispersing fish populations. Despite over a century of research, a critical gap remains in quantifying the energetic strategies of developing fish to determine how species from different thermal environments self-regulate in response to chronic and acute temperature changes and, the energetic costs associated with allostatic adjustments, referred to as allostatic load (RAL). This study examines the metabolic differences in yolk-sac larvae and their capacity to adjust to energetically adjust to chronic and acute temperature change. We studied the yolk-sac stages of two species: (1) zebrafish (Danio rerio, a tropical eurythermal freshwater fish) and (2) Atlantic cod (Gadus morhua, a cold-temperate stenothermal marine fish), under control (C) conditions (28°C for zebrafish and 5°C for Atlantic cod) and compared responses to larvae raised at chronic higher temperatures (31°C for zebrafish and 10°C for Atlantic cod) and exposed to acute temperature change for 1 h in a respirometer (3°C, zebrafish and 5°C, Atlantic cod) during the first week of larval life. Generally, both species exhibited higher metabolic rates and greater energetic-related changes in response to chronic stressors than to acute stressors compared to C conditions. While an acute increase in temperature resulted in some metabolic compensation, acute decrease in temperature led to what appeared to be metabolic dysregulation. Both species demonstrated higher variability in response to acute decreases in temperature compared to other treatments. Overall, the range of metabolic responsiveness was greater in Atlantic cod than in zebrafish, suggesting that stenothermal Atlantic cod have less resilience to changes in temperature than eurythermal zebrafish, at least at the yolk-sac stage and, during the first week of larval life when the yolk limits energy supply.

Network science has had a great impact on ecology by providing tools to characterize the structure of species interactions in communities and evaluate the effect of such network structure on community dynamics. This has been particularly the case for the study of plant-pollinator communities, which has experienced a tremendous growth with the adoption of network analyses. Here, I build on such body of research to evaluate how network structure and adaptive foraging of pollinators affect ecosystem services of plant-pollinator communities. Specifically, I quantify-using model simulations-pollen deposition in networks that exhibit structures like the ones of empirical networks (hereafter empirically connected networks) and those with higher connectance and lower nestedness than empirical networks, for scenarios where pollinators are fixed foragers and scenarios where they are adaptive foragers. I found that empirically connected networks with adaptive foraging exhibit the highest pollen deposition rate. Increased network connectance reduces pollen deposition, as increased number of interactions leads to greater conspecific pollen dilution in the absence of other mechanisms such as pollinator floral constancy. High nestedness in moderately connected networks increases the proportion of pollinators visiting only one or two plant species, which are associated with the highest quality visits. Adaptive foraging allows pollinators to quantitatively specialize on specialist plant species, which increases conspecific pollen deposition. This research advances pollination biology by elucidating how population dynamics, consumer-resource interactions (i.e., pollinators foraging on floral rewards), adaptive foraging, and network structure (i.e., nestedness and connectance) affect pollen deposition in a network context.

Although fishes constitute nearly half of all known vertebrate diversity, their dentitions remain remarkably understudied. This is due in part to the challenges of continual tooth replacement, high variation in tooth form and number along the jaws, and a two-jaw system that allows for prey capture and processing to be decoupled. To help address this gap in our knowledge, we provide a guide to best practices when implementing Orientation Patch Count Rotated (OPCR) to measure tooth surface complexity in fishes using microCT scans. OPCR has been successfully applied across numerous studies of mammal and reptile dentitions but is yet to be applied to fishes. We provide an open-source 3D-OPCR workflow for fish dentitions along with the results from five investigations that illustrate how methodological choices relevant to implementing OPCR in fishes can impact OPCR output. Our goal is to provide comparative biologists with a useful framework that leverages open access software to conduct their own integrative studies on dental complexity in fishes and other vertebrates where whole jaw analyses are useful. We view 3D-OPCR as a powerful but underutilized tool for quantifying patterns of dental variation in fishes that has potential for cross-disciplinary application within the integrative and comparative biology community.

Animal-mediated pollination is one of the most ecologically and economically important mutualisms and serves as a remarkable example of cross-kingdom communication and coevolution. Unfortunately, pollinators, plants, and the interactions between them are threatened in the Anthropocene. While pollination emerges from interactions across biological scales, existing research and expertise have developed in distinct silos reflecting traditional fields of study such as ecology, plant physiology, neuroethology, etc. This forward-looking review and perspective is a culmination of the "Plant-pollinator interactions in the Anthropocene" symposium at the 2025 Society for Integrative and Comparative Biology meeting, which collected expertise across these disciplinary silos to identify pressing questions our community needs to tackle in the next decade. In this perspective piece, we argue that an integrative, organismally informed systems approach is critical to unraveling the complexity of how plant-pollinator relationships are impacted by dynamic anthropogenic stressors. Specifically, this calls for an intentional and iterative integration of holistic modeling studies with empirical studies. Modeling the emergent properties driven by organismal interactions in pollination systems can identify impactful variables; this in turn should drive design of empirical studies that elucidate how organisms respond to changing environments in the context of those impactful variables, feeding back into improved models. Repetition of this process will allow better predictive power over pollination stability in changing landscapes. Finally, we consider both existing barriers to this integration, as well as emerging opportunities (such as new technologies) that can help bridge across traditional fields.

Understanding the mechanisms that underlie resilience in marine invertebrates is critical as climate change and human impacts transform coastal ecosystems. Metabolic plasticity, or an organism's capacity to modulate energy production, allocation, and use, plays a central role in mediating resilience under environmental stress. While research on marine invertebrate stress responses has grown, integrative studies that examine metabolic plasticity by connecting molecular, physiological, and organismal scales remain limited. In this Perspective, we advocate for the rigorous and thoughtful use of metabolomic and lipidomic approaches to understand resilience in marine systems through the lens of metabolic plasticity. We provide recommendations for experimental design, summarize current methodologies, and provide an overview of commonly used data analysis approaches. Advances in other molecular approaches such as genomics, epigenomics, and transcriptomics can be harnessed to further explore stress responses through multi-omic integrative analyses. As quantitative integrative analysis remains limited in marine fields, we call for a stronger integration of molecular, metabolomic, physiological, and organismal data sets to link mechanisms to phenotypes. We explore the use of these approaches in studies of marine invertebrates and highlight promising areas of multi-omic research that deserve exploration. By embracing metabolic complexity and scaling from molecules to phenotypes, we suggest that the marine invertebrate research community will be better equipped to understand, anticipate, and mitigate the impacts of environmental change on marine ecosystems.

Ecological specialization is often described as an evolutionarily tenuous, or dead-end, strategy, where the loss of one partner may be catastrophic for the other. Some of the most highly specialized interactions are brood-pollination mutualisms, wherein plants trade food and shelter for pollination services, often at the cost of some offspring (i.e., fertile seeds). With few exceptions, brood-pollination mutualisms are generally obligate, thus the reproduction of both plant and insect pollinator are interdependent and cannot occur without the other. In many cases, these interactions are also species-specific and pairwise. Due to the severity of reproductive constraint, an evolutionary "dead-end" seems all but inevitable. However, host-shifts are remarkably common, even in brood-pollination mutualisms, and may enhance evolutionary resilience. Yet, we still lack a clear understanding of mechanisms of insect localization and choice of a new host-plant in these highly specialized mutualisms. Recently, Rhopalotria furfuracea, the specialized brood-site pollinator of the cycad Zamia furfuracea, has been observed on other Zamia species in an artificial environment (i.e., a conservation garden) where it is not found in the wild. To better understand what cues are facilitating this shift, we consider both "private channels", or unique secondary metabolites thought to facilitate partner fidelity in ecologically specialized interactions, and the more general cue humidity, representing 2 modes of signaling for which the ecological importance has been previously described in the R. furfuracea-Z. furfuracea mutualism. We hypothesize that humidity will increase pollinator attraction to non-host plant scent. To test this, we characterize via gas chromatography mass spectrometry the previously unreported scent of the non-host plant, Z. paucijuga, that R. furfuracea has recently colonized and find that it qualitatively differs from that of Z. furfuracea. Behavior trials, consisting of 2-way y-tube olfactometer choice assays find that weevils are repelled by the non-host plant volatile blend, but that the addition of humidity overcomes avoidance behavior, suggesting that less specialized traits, such as primary metabolites, may create opportunities for novel associations to develop over evolutionary time.

The Western honey bee (Apis mellifera L.) has been managed by humans for centuries for honey, wax, and most recently, crop pollination. The deep history of human association with this species has enabled agricultural practices that reduce biodiversity of pollinating wild bees, largely through habitat modification. However, there is also interest in determining if A. mellifera presence itself contributes significantly to wild bee population declines. Here, we review the evidence of A. mellifera effects on wild bees, with a particular emphasis on critically evaluating the evidence for detrimental impacts associated with resource competition. Despite accelerated research in this area, only ∼13% of resource competition studies evaluated fitness effects of A. mellifera on wild bees, a research gap that has persisted for over 20 years. About three times as many studies have evaluated effects of A. mellifera on wild bee community parameters, including wild bee abundance, which provides a measure of a landscape's "bee carrying capacity." Just over 20% of these studies show a negative correlation with A. mellifera abundance. In a novel analysis of 68 additional studies measuring bee communities for a variety of other reasons, we found negative correlations between A. mellifera abundance and any measure of the wild bee community (richness, abundance, etc.) for nine, and the measures showing A. mellifera impacts were varied. For example, only two of these studies showed negative correlations between A. mellifera and wild bee abundances. In contrast, we also found similar numbers of positive relationships between A. mellifera and various wild bee community parameters, including ten studies that showed positive relationships between A. mellifera and wild bee abundances. Most studies (64%) showed no relationship with any factor. We found no clear pattern to explain which habitat types are more vulnerable to A. mellifera competition, nor is the literature clear on impactful densities of managed hives in particular environment types. We discuss suggestions for future research, as well as ways the research community could clarify its conservation priorities with respect to resource competition. Resource competition between A. mellifera and wild bees is clearly a concern in some cases. However, more work is needed to identify and predict where A. mellifera poses a significant threat to wild bee populations. Overall, the data do not support a generalized and widespread negative relationship between A. mellifera abundance and wild bee community health. Rather, conservation measures that reliably improve wild bee health (habitat preservation and restoration) will likely have positive effects on A. mellifera, and vice versa.

Temperature is a major driver of individual performance in ectotherms, with this impact depending on stressor intensity and duration. Differences in individual response across temperature, time, and populations are shaped by the interplay between evolutionary adaptation and phenotypic plasticity. Some populations are able to thrive in novel and changing environments despite limited genetic diversity, raising the question of how plasticity and adaptation interact after significant genetic diversity loss. The European green crab (Carcinus maenas) is a textbook example of this phenomenon: invasive populations boast a broad thermal tolerance and exceptional thermal flexibility even after repeated genetic bottlenecks. Despite this loss of diversity overall, prior work has found a strong population-level association between variation at a specific extended genomic region (supergene), cold tolerance, and sea surface temperature. We conducted a series of three experiments using righting response to characterize sublethal thermal tolerance and plasticity in introduced green crab populations, then determined if these factors were associated with supergene genotype for individual adult crabs. Crabs showed signs of stress after exposure to a 30°C heat shock in one experiment. Interestingly, a second experiment exposing C. maenas to repeated 24-h heat shocks showed that prior heat shock conferred beneficial plasticity during a subsequent event. The third experiment examined cold acclimation over multiple timepoints up to 94 h. At 5°C, certain crabs exhibited an acclimatory response where righting slowed dramatically at first, and then gradually sped up after a longer period of cold exposure. Several crabs failed to right at 1.5°C, which could be indicative of dormancy employed to reduce energy consumption in colder conditions. There were no significant relationships between individual plasticity and supergene genotype in any experiment. Linking population-level genetic associations with individual-level physiology is complex, and reflects the impact of environmental conditions such as temperature throughout life history in shaping adult phenotype. Our results highlight the robust thermal tolerance and plasticity that adult green crabs maintain despite a substantial reduction in genetic diversity, and underscore the importance of probing population-level genotype-phenotype associations at the individual level.

Ectothermic species in lowland tropical forests have evolved in historically stable climates, leading to the prediction that transcriptomic and phenotypic plasticity do not play major roles in their responses to changes in environmental temperature. However, these species are often thermoconformers and are therefore exposed to short-term temporal fluctuations in temperature. Hence, transcriptomic plasticity in tropical forest ectotherms might replace behavioral thermoregulation as a mechanism to buffer against thermal stress. In particular, upregulation of heat shock proteins can occur during thermal stress in a range of organisms. However, while many studies have explored gene expression plasticity in response to heat stress in model organisms, little is known about transcriptomic plasticity in the tropical, non-model species that will be the most impacted by climate change. We studied the effects of moderate and severe acute heat stress events in the Panamanian slender anole (Anolis apletophallus) to gain insight into a mechanism that might allow tropical ectotherms to withstand the heat waves that are likely to rise in frequency over the coming decades under anthropogenic climate change. We found that multiple genes were upregulated across several heat shock protein networks in three tissues, and the magnitude of the expression response was similar irrespective of whether heat stress was moderate or severe. Overall, our results indicate a potentially crucial role for heat shock protein networks in the ability of tropical ectotherms to resist the negative effects of rising temperatures.

When animals compete over essential and limited resources, how they gather information about fighting ability is a crucial factor influencing their decision-making. Most research in animal contests asks how decisions are made when facing a single competitor; however, in many cases, individuals face multiple potential opponents and may incorporate information on this social environment. In addition, recent research suggests that animals perceive contest-relevant stimuli like body size in a proportional, not absolute, manner; this proportional processing has rarely, if ever, been incorporated into studies of contest assessment. Green swordtail fish (Xiphophorus hellerii) live in social aggregations, in which males may defend females from multiple potential opponents. Here, we asked how focal male green swordtails defended live females when presented with two simulated males that differed by known sizes. We found that focal males spent less time near the larger, more salient, of the two competitors as the mean size of both simulated competitors increased. That is, focal males mainly used information on the social environment to make competitive decisions, as opposed to information about own or relative fighting ability as commonly assumed in most contest theory. We also found that males who spent less time with the largest competitor shifted their attention to the defended female, devoting more time near this resource. Our findings suggest that, when there are multiple potential competitors, common models of decision-making in contests may be less applicable than previously assumed. Further, given the common use of proportional processing across animals, we suggest that future work on contests incorporates this type of perception.