Biology Letters最新文献

{"title":"Predator-prey scaling laws support a suspension-feeding lifestyle in Cambrian luolishaniid lobopodians.","authors":"Jared C Richards, Javier Ortega-Hernández","doi":"10.1098/rsbl.2025.0650","DOIUrl":"10.1098/rsbl.2025.0650","url":null,"abstract":"<p><p>The early Palaeozoic saw a dramatic diversification of shelly epibenthic metazoans adapted to suspension and filter feeding, but the extent to which these radiations affected the evolution of non-biomineralized suspension-feeding taxa is uncertain because these organisms are not typically well represented in the fossil record. Luolishaniids are a highly derived and disparate clade of (typically) armoured lobopodians, widely interpreted as suspension feeders based on the presence of five or six anterior pairs of setulose appendages. Luolishaniids are globally widespread and represent the only Cambrian non-biomineralized free-living epibenthic bilaterians suggested to have a suspension-feeding mode of life, but their proposed ecology relies solely on a qualitative interpretation of their functional morphology. Here we test the hypothesis that the setulose appendages of luolishaniids were adapted for a suspension-feeding function. Quantitative morphological comparisons reveal a positive and statistically significant relationship between body length and the mesh spacing of the setulose anterior limbs of luolishaniids. Standardized comparisons indicate that the body size disparity between luolishaniids (predators) and Cambrian mesoplankton (prey) is consistent with patterns observed in modern suspension-feeding organisms. We provide quantitative evidence for suspension feeding in luolishaniids, which represents the first statistically supported example of modern-like predator-prey scaling patterns observed in Cambrian soft-bodied metazoans. Despite the uncanny appearance of luolishaniids, and Cambrian organisms more broadly, our results suggest their adaptations and mode of life feature ecological attributes shared with modern marine invertebrates.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147761372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wide-ranging, year-round breaching behaviour of basking sharks revealed by long-term biologging.","authors":"C Antonia Klöcker, Mikko Vihtakari, Martin Christopher Arostegui, Axel Schlindwein, Keno Ferter, Otte Bjelland, Haley R Dolton, Øystein Langangen, Nuno Queiroz, David W Sims, Claudia Junge","doi":"10.1098/rsbl.2025.0696","DOIUrl":"10.1098/rsbl.2025.0696","url":null,"abstract":"<p><p>Marine megafauna, including various species of cetaceans and fishes, exhibit energetically costly breaching behaviour during which individuals rapidly propel themselves out of the water. The function of breaching remains enigmatic, largely due to short-duration observations of limited spatial extent. Here, we used animal-borne biologgers to record breaching events of plankton-feeding basking sharks (Cetorhinus maximus) over full annual cycles at high temporal resolution (5 s) across broad spatial scales (35° latitude). Recording 577 breaches across four individuals over 366 days (mean 144 yr⁻¹ shark⁻¹), breaching appears to be a routine behaviour in both sexes, peaking in autumn, but occurring across all seasons and habitats, including deep oceanic areas. Notably, we identified thermal constraints on breaching rates in colder water, with a critical minimum observed at 5°C. Beyond demonstrating that breaching is more common than previously recognized, our study suggests it serves several functions, some potentially independent of spatial and temporal contexts (e.g. seasonal courtship), such as ectoparasite removal. The ubiquity of breaching across space and time highlights the need for comprehensive 'behaviour maps' for ocean giants to elucidate the physiological constraints, ecological significance and management implications of breaching in a changing ocean.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147761354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Humidity induces structural colour change and contributes to biogeographic colour variation in sweat bees.","authors":"Madeleine M Ostwald, Leslie Cervantes Rivera, Jorge De La Cruz, Katja C Seltmann","doi":"10.1098/rsbl.2025.0803","DOIUrl":"10.1098/rsbl.2025.0803","url":null,"abstract":"<p><p>Dynamic coloration is one of the most striking visual displays in the animal kingdom. While reversible colour changes are well characterized in animal communication, more passive effects of climate on baseline coloration remain poorly understood. Here, we present a novel experimental demonstration of reversible, humidity-induced colour change in bees. In controlled lab experiments, we show that relative humidity affects cuticle colour of the sweat bee Agapostemon subtilior, changing dramatically within 24 h from a deep blue-green at low humidity to a pale, coppery green at high humidity. Older specimens experienced greater magnitude colour shifts, suggesting that cuticular degradation may increase water permeability and amplify moisture effects. To understand whether these effects shape colour variation in the wild, we extracted colour data from a large dataset of crowd-sourced field images. We found that ambient humidity weakly predicts colour variation across A. subtilior's western range, in a manner consistent with the direction of colour change established in lab experiments. While the structural basis for this colour change is still unknown, these shifts are directionally consistent with moisture-induced swelling of multilayer structures that causes reflection of longer wavelengths, a mechanism described in other insects and cephalopods. Together, these results demonstrate that climate modulates structural coloration in bees, emphasizing the role of abiotic conditions in shaping dynamic visual traits.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147761374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nematode infections induce distinct chemical signatures and provoke aggression in ants.","authors":"Bhoomika Ashok Bhat, Nan-Ji Jiang, Rayko Halitschke, Yuko Ulrich","doi":"10.1098/rsbl.2025.0716","DOIUrl":"10.1098/rsbl.2025.0716","url":null,"abstract":"<p><p>Maintaining group integrity by excluding outsiders and pathogens is a fundamental requirement and challenge of social living. In social insects, these defences rely heavily on chemical communication, with cuticular hydrocarbons (CHCs) mediating both nestmate recognition and infection-related social responses. In ants, CHCs are stored and homogenized in the pharyngeal gland, contributing to the formation of a shared colony odour that enables nestmate recognition. We investigated the behavioural and chemical responses of the clonal raider ant Ooceraea biroi to infections by the nematode Diploscapter sp., which specifically infects the pharyngeal gland. Using behavioural and chemical analyses, we show that: (i) infected ants elicit increased aggression from uninfected nestmates and non-nestmates, consistent with a social immune defence that may limit parasite entry in colonies; (ii) aggression correlates with infection-specific changes in CHC profiles; and (iii) infections do not compromise nestmate recognition, which mostly acts through CHCs different from those altered by infection. Thus, while many parasitic nematodes can evade host immune recognition, Diploscapter fails to evade the social recognition system of its host. Instead, efficient detection of and aggression towards infected individuals likely reduce parasite introduction and transmission both within and between colonies.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147761393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lamellar surface area calculations support respiratory function of trilobite exopodites.","authors":"Sarah R Losso, Federica Vallefuoco, Igino Foglia, Léo Laborieux, Ana Belén Muñoz-García, Javier Ortega-Hernández","doi":"10.1098/rsbl.2026.0071","DOIUrl":"10.1098/rsbl.2026.0071","url":null,"abstract":"<p><p>Trilobites had biramous appendages with an inner endopodite (walking leg) and outer exopodite (gill) connected to the body through the protopodite (limb base). Whereas both endopodite and protopodite were involved in locomotion and feeding, the exopodite has been subject to various functional interpretations including respiration, ventilation and swimming. Evidence from sites with exceptional fossil preservation indicates that trilobite exopodites show substantial variability in terms of the number and size of their articles, lamellae and setae, but the implications of this morphological diversity have never been investigated. Here, we created anatomically correct three-dimensional models of exopodites in Olenoides serratus and Triarthrus eatoni to calculate the surface area (SA) of the lamellae and explore its relationship with body size. Lamellar SA of O. serratus was 16 589 mm2 (for a specimen 67.8 mm sagittal length) compared with the smaller T. eatoni 2159 mm2 (36.3 mm sagittal length). We also calculated SA for nine additional trilobite species with well-preserved appendages based on lamellar measurements. The results indicate that lamellae SA of trilobites increased exponentially with overall body size. Trilobite data follows the same trendline of gill SA/biomass observed in extant species and thus supports the interpretation of their exopodites as respiratory structures despite substantial variation in morphology.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147761433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Migrating by night, inactive by day: ecological barrier crossing in a migratory songbird.","authors":"Pablo Macías-Torres, Anders Hedenström","doi":"10.1098/rsbl.2026.0055","DOIUrl":"10.1098/rsbl.2026.0055","url":null,"abstract":"<p><p>Long-distance migratory songbirds cross ecological barriers such as deserts and seas as part of their journeys. Yet, the behavioural adaptations used to perform these crossings remain poorly understood. Using accelerometer data from multisensor loggers carried by free-flying thrush nightingales (Luscinia luscinia), a nocturnal migratory passerine, we quantified fine-scale activity patterns during the entire migratory journey, including desert crossings during both spring and autumn migration. When migrating over ecological barriers, the birds performed consecutive nocturnal migratory flights, followed by daytime layovers when the birds remained inactive until the next sunset, when resuming migratory flights. The absence of diurnal locomotion while crossing desert environments suggests that thrush nightingales do not refuel while stopping within the barriers but instead rely on energy reserves accumulated prior to barrier entry. This multi-day behavioural inactivity highlights physiological and energetic constraints faced by small migratory birds when crossing ecological barriers and illustrates the careful allocation of energy reserves prior to the barrier crossing to endure several consecutive migratory flights without refuelling. Our results provide new detailed insights into how long-distance migrants cross ecological barriers, improving our understanding of behavioural adaptations in bird migration ecology.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147761367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Absence of supergene-linked determination of wing polymorphism and alternative reproductive strategies in the ant Hypoponera opacior.","authors":"Anna Lenhart, Hugo Darras, Susanne Foitzik","doi":"10.1098/rsbl.2026.0070","DOIUrl":"10.1098/rsbl.2026.0070","url":null,"abstract":"<p><p>Social insects frequently exhibit intraspecific variation in reproductive strategies, characterized by pronounced differences in the morphology, physiology and behaviour of reproductive individuals and the social organization of the colony. In many ant species, this complex variation is governed by supergenes that control multiple traits, including queen morphology and dispersal behaviour, as well as the number of queens that can coexist within a colony. Here, we investigate the genetic basis of sexual dimorphism in the ant Hypoponera opacior, which produces both winged and wingless morphs in males and queens, each associated with distinct reproductive behaviours and seasonal activity. Using whole-genome resequencing of all morphs, we tested for signatures of supergene architecture. Our analyses revealed no evidence for a supergene or other large genomic rearrangement underlying this morphological and behavioural diversity. These findings suggest that male and queen morph determination in H. opacior is not controlled by a large structural polymorphism and may instead result from phenotypic plasticity, environmentally sensitive developmental switches or polygenic factors. Our study demonstrates that complex social traits in ants can evolve and persist without supergene architectures and underscores the importance of considering alternative genetic and epigenetic mechanisms underlying reproductive polymorphisms.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147761441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sex differences in the enjoyment of enrichment: affective bias testing confirms female rats prefer more playful and less vigorous tickling.","authors":"Catalina Gonzalez, Alistair B Lawrence, Michael Mendl, Emma Robinson, Vincent Bombail, Sarah M Brown","doi":"10.1098/rsbl.2026.0075","DOIUrl":"10.1098/rsbl.2026.0075","url":null,"abstract":"<p><p>There is increasing interest in positive animal welfare which emphasizes that animals should experience predominantly positive mental states. Positive animal welfare raises challenging biological questions, including how we assess positive experiences. Rat tickling mimics rough and tumble play; it is applied to improve welfare and study positive affect, often using ultrasonic vocalizations (USVs) to assess rats' affective state. Standard tickling protocols involve frequent pinning where the supine rat is vigorously tickled on its belly, which we have argued may not be positive for all rats. Here, using an affective bias test, we show that both sexes experience positive affective states when tickled, but females, unlike males, prefer playful tickling with minimal pinning. This result corresponds with our previous work using USVs to assess rats' affective response to tickling, further validating USV recording as a marker of positive affective states. We believe this to be the first example where a refinement aimed at enhancing positive, rather than minimizing negative, mental states in animals has been independently validated; this should provide a model for similar studies in other species. In rats, this refinement should enhance welfare and more generally demonstrate the importance of considering sex differences when designing welfare interventions.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147688001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental infections with a honey bee virus induce fitness costs in ant colonies.","authors":"Lai Ka Lo, Ashmita Baruah, Robert J Paxton, Yuko Ulrich","doi":"10.1098/rsbl.2025.0779","DOIUrl":"10.1098/rsbl.2025.0779","url":null,"abstract":"<p><p>Acute bee paralysis virus (ABPV) is a key driver of honey bee colony losses that has been increasingly reported in non-bee hosts. Ants have long been hypothesized to act as viral reservoirs, but most evidence comes from field surveys and experimental tests are still scarce. Here, we combined survival and transmission assays, viral load quantification and viral replication assays following experimental inoculations to test whether the clonal raider ant Ooceraea biroi can harbour and transmit ABPV within its colonies. ABPV-injected immatures and adults showed delayed development and elevated mortality, respectively. Viral replication assays suggested these fitness costs were caused by host responses (e.g. immunopathology) rather than viral replication. Viral particles persisted for days in inoculated ants, and high viral loads were detected in untreated colony members after 1-3 days of cohabitation with ABPV-injected pupae or adults, indicating rapid viral spread. These results show that ants can acquire ABPV, incur fitness costs and pass on the virus within their colonies, suggesting that they may act as incidental viral reservoirs. By maintaining and disseminating honey bee viruses, even without supporting replication, ants may contribute to their environmental persistence and spillover across species.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147687961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Light and drug effects reveal three pathways for nitric oxide modulation of the first visual synaptic relay in the lamina ganglionaris.","authors":"Hugo Alejandro Álvarez, Jorge Cebada, Carmen Grijota-Martínez, Laura Ivón Láscarez-Lagunas, Amira Flores-Urbina","doi":"10.1098/rsbl.2025.0653","DOIUrl":"10.1098/rsbl.2025.0653","url":null,"abstract":"<p><p>The modulation of synaptic relay mechanisms in the visual pathway remains a significant area of investigation. Here, we explore the role of nitric oxide (NO) in the eyestalks of the Australian blue crayfish Cherax quadricarinatus, focusing on its relationship with light exposure and potential regulatory pathways involving NO promoters and inhibitors. NO levels in the eyestalks were assessed using the Griess technique under various light-dark cycles and different physiological parameters (size, weight and sex) of adult crayfish. We found a light-dependent modulation of NO concentration, with constant light exposure significantly elevating NO levels compared with periods where darkness is involved and a negative trend as darkness increased. Interestingly, size, weight and sex variations showed no discernible impact on NO levels. Moreover, the influence of histamine (a primary neurotransmitter involved in the first visual synaptic relay) and a nitric oxide synthase (NOS) inhibitor, such as NG-nitro-l-arginine methyl ester (l-NAME), or the H2-blocker ranitidine, was investigated. As expected, histamine notably enhanced NO synthesis, whereas NOS inhibitors and H2 blockers led to substantial reductions in nitrite concentrations. The findings point to three possible mechanisms of action: (i) a light-induced release of histamine from retinal photoreceptors that activates postsynaptic receptors in lamina ganglionaris monopolar neurons, inducing NO synthesis and retrograde modulation of the photoreceptor; (ii) a histamine-dependent activation of postsynaptic receptors in monopolar cells that promotes NOS-mediated NO production, which retrogradely recruits lamina interneurons (e.g. GABAergic horizontal/amacrine cells) to mediate lateral inhibition of photoreceptors through GABA and/or ACh; and (iii) a mechanism in which light-induced histamine release activates photoreceptor auto-receptors, leading to NO release from the photoreceptor to cells of the lamina ganglionaris.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"22 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147687969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}