Specific Microhabitats Research Articles

Modelling the present and future of Phrynosoma orbiculare habitat and wildfire distribution and their environmental niche overlap in Mexico

Wildfires are natural phenomena that have shaped ecosystems and maintained biodiversity for millions of years. However, the increased frequency and severity of wildfires in recent decades are predominantly attributed to human activities. These anthropogenic factors, including land use change, climate change, and fire suppression, have disrupted the natural fire regime and heightened the risk of large-scale, destructive wildfires. Reptiles, as ectothermic and often slow-moving animals, are particularly vulnerable to the effects of fires due to their limited mobility and reliance on specific microhabitats. Understanding the impacts of wildfires on reptile populations is crucial for their effective conservation and management in fire-prone areas. This paper focuses on Phrynosoma orbiculare, a species distributed across the northern and southeastern regions of Mexico, where wildfires are common. The study revealed that key environmental variables driving the distribution of P. orbiculare include altitude, temperature extremes, and forest composition, while fire occurrence is strongly influenced by climatic conditions such as temperature and precipitation. As fires become more frequent and severe, the niche overlap between P. orbiculare and fire-prone regions is expected to expand. These findings highlight the importance of integrating fire management into conservation planning, particularly for protecting fire-sensitive ecosystems like Abies forests. Understanding the complex interaction between fire and species distributions is essential for developing effective conservation strategies that ensure the survival of P. orbiculare and other fire-sensitive species in Mexico’s changing landscapes.

Comparative Population Genomic Diversity and Differentiation in Trapdoor Spiders and Relatives (Araneae, Mygalomorphae).

Although patterns of population genomic variation are well-studied in animals, there remains room for studies that focus on non-model taxa with unique biologies. Here we characterise and attempt to explain such patterns in mygalomorph spiders, which are generally sedentary, often occur as spatially clustered demes and show remarkable longevity. Genome-wide single nucleotide polymorphism (SNP) data were collected for 500 individuals across a phylogenetically representative sample of taxa. We inferred genetic populations within focal taxa using a phylogenetically informed clustering approach, and characterised patterns of diversity and differentiation within- and among these genetic populations, respectively. Using phylogenetic comparative methods we asked whether geographical range sizes and ecomorphological variables (behavioural niche and body size) significantly explain patterns of diversity and differentiation. Specifically, we predicted higher genetic diversity in genetic populations with larger geographical ranges, and in small-bodied taxa. We also predicted greater genetic differentiation in small-bodied taxa, and in burrowing taxa. We recovered several significant predictors of genetic diversity, but not genetic differentiation. However, we found generally high differentiation across genetic populations for all focal taxa, and a consistent signal for isolation-by-distance irrespective of behavioural niche or body size. We hypothesise that high population genetic structuring, likely reflecting combined dispersal limitation and microhabitat specificity, is a shared trait for all mygalomorphs. Few studies have found ubiquitous genetic structuring for an entire ancient and species-rich animal clade.

Integrating geodiversity in animal spatial ecology: microhabitat selection of Eurasian lynx (Lynx lynx) and European wildcat (Felis silvestris) in a karst landscape

Geodiversity, encompassing various geophysical elements, can have an important impact on species distribution and affect animal behaviour patterns. Although many wild felids are attracted to rugged terrain and conspicuous relief features, most previous research was limited to general topographical characteristics (e.g., slope or terrain ruggedness) and rarely considered the effects of specific microhabitat characteristics. This gap is primarily due to the limited availability of high-resolution digital terrain models (DTMs) and relief features data at larger scales. However, LiDAR DTMs can be used in combination with various automatic methods to detect relief features, enabling non-contact and accurate mapping of large, remote and densely-forested areas. Here, we investigated the selection patterns of various karstic relief features, as well as topographic, anthropogenic and vegetation characteristics, by two sympatric felids, the Eurasian lynx (Lynx lynx) and the European wildcat (Felis silvestris), in the Dinaric Mountains, Slovenia. We used LiDAR DTM to calculate topographic characteristics and detect karst relief features based on automatic methods. We compared the selection of these features between the GPS-collared lynx and wildcats under a use-availability approach. We also investigated the differences in the selection of these features by lynx based on their origin and experience (remnant vs. translocated and naive vs. experienced, respectively). We observed significant impact of relief features on space use by both felids and detected distinct selection patterns between the two species. Lynx selected rugged terrain and proximity of caves, cliffs, karst depressions, ridges, small rocky outcrops, and roads, but avoided human settlements and forest edges. Wildcats selected areas with lower surface slope, closer to main roads, forest edges, caves and ridges, but avoided cliffs, forest roads and human settlements. We observed stronger selection/avoidance patterns among the translocated compared to the remnant lynx, while the differences in experience levels were less important. Our study demonstrates the potential of integrating remote sensing techniques and information on geodiversity into the study of animal spatial ecology. Furthermore, our results indicate that specific relief features provide important abiotic microhabitats for felids and may influence habitat segregation between sympatric species. Our findings provide further evidence for the importance of geodiversity conservation and the need to incorporate abiotic microhabitat features in wildlife habitat selection studies.

Investigating the nursery function of the Alboran MPA on the Mediterranean coast of Morocco

Coastal habitats provide shelter and food for juvenile fish, ensuring their survival and supporting a range of species that are both commercially and ecologically important. The Alboran Marine Protected Area (MPA) off the Mediterranean coast of Morocco has been identified as a nursery area, although this role has never been the subject of characterisation. This study investigates the nursery function of habitats at six sites, two of which have seasonally flooded rivers with small persistent lagoons (transition systems) actively connected to the sea. Mixed sand-and-gravel beaches and transition systems were surveyed using a beach seine (four hauls) during two consecutive summer periods (June 2019 and July 2020), and a beam trawl was used in July 2020 in order to survey shallow waters at three depths: 3, 5 and 7 m. The use of both fishing methods provided a comprehensive assessment of juvenile fish communities. Different habitats in these coastal areas supported juvenile fish of 31 different species, with higher species richness and densities of young-of-the-year (YOY; first year of life) fish in transition systems despite their limited surface area and depth. Shallow marine waters supported fish species with specific microhabitat requirements despite lower overall YOY fish densities. The Alboran MPA coast has a nursery function, with different habitats acting as nurseries for juveniles of different fish species, creating a seascape of interconnected nursery habitats. As low densities of juvenile fish were a common concern across species and habitats, protecting these nursery habitats through enforcement of their protection regime appears to be a priority.

Coping with unpredictable environments: fine-tune foraging microhabitat use in relation to prey availability in an alpine species.

Microhabitat utilisation holds a pivotal role in shaping a species' ecological dynamics and stands as a crucial concern for effective conservation strategies. Despite its critical importance, microhabitat use has frequently been addressed as static, centering on microhabitat preference. Yet, a dynamic microhabitat use that allows individuals to adjust to fine-scale spatio-temporal prey fluctuations, becomes imperative for species thriving in challenging environments. High-elevation ecosystems, marked by brief growing seasons and distinct abiotic processes like snowmelt, winds, and solar radiation, feature an ephemeral distribution of key resources. To better understand species' strategies in coping with these rapidly changing environments, we delved into the foraging behaviour of the white-winged snowfinch Montifringilla nivalis, an emblematic high-elevation passerine. Through studying microhabitat preferences during breeding while assessing invertebrate prey availability, we unveiled a highly flexible microhabitat use process. Notably, snowfinches exhibited specific microhabitat preferences, favoring grass and melting snow margins, while also responding to local invertebrate availability. This behaviour was particularly evident in snow-associated microhabitats and less pronounced amid tall grass. Moreover, our investigation underscored snowfinches' fidelity to foraging sites, with over half located within 10m of previous spots. This consistent useprevailed in snow-associated microhabitats and high-prey-density zones. These findingsprovide the first evidence of dynamic microhabitat use in high-elevation ecosystems and offer further insights into the crucial role of microhabitats for climate-sensitive species. They call for multi-faceted conservation strategies that go beyond identifying and protecting optimal thermal buffering areas in the face of global warming to also encompass locations hosting high invertebrate densities.

Evaluation of speculated reproductive habitat for Somatochlora calverti (Corduliidae), a rare and range-restricted dragonfly

Globally, freshwater ecosystems and the organisms that depend on them are at risk. Dragonflies and damselflies (collectively, “odonates”) have a history of being used as bioindicators of freshwater habitat quality due to their wide range in environmental sensitivities across species and because they are relatively accessible. However, the nymphal stage is severely understudied compared to the adult stage, which inhibits conservation efforts. Somatochlora calverti is a rare species of dragonfly in the family Corduliidae; members of the genus Somatochlora are notoriously difficult to find and collect in the field as nymphs and adults. Somatochlora calverti is known primarily from the Florida panhandle but has been documented in Alabama, Georgia, and South Carolina. The nymph of this species is speculated to use seepage streams analogous to sympatric congeners; however, the nymph has never been collected in the field and, therefore, its specific microhabitat is unknown. We conducted a review from a suite of informational sources to generate a holistic consensus on what is defined to be suitable reproductive habitat for S. calverti. Sources identified eight major environmental characteristics that are likely to harbor S. calverti: shallow seepage streams, including steephead ravines, with undercut banks and mats of Sphagnum moss adjacent to intact sandhill forest. These ecosystems are being lost and degraded by anthropogenic activity, which has considerable impacts on the persistence of habitat specialists, including S. calverti, and managers’ ability to conserve them.

Role of generalists, specialists and opportunists in Nitrospira community assembly in soil aggregates from nearby cropland and grassland areas in a campus

Nitrospirota is an essential contributor to nitrification. However, the community assembly mechanism of such organisms in soil aggregates from nearby but different ecosystems is unclear. We quantitatively measured the relative contributions of generalists, opportunists and specialists to the Nitrospira community assembly. Nitrospira were more abundant in agricultural soils than in grasslands and were relatively enriched in microaggregates in both agricultural (AS) and grassland soils (GS). These findings could be explained by the neutral pH of AS and the relatively high organic carbon quantity of the aggregates. The community variation in Nitrospira was driven by both ecosystem and aggregate size fractions, with dispersal and drift dominating the assembly process, partly explained by macro- and microaggregates with higher organic quality that can reduce selection pressures to enrich Nitrospira species (indicated by a higher α diversity), supporting more stochastic processes (drift and dispersal limitations) in community assembly. Generalists belonging to Namibia soil cluster 2, followed by unknown Nitrospira and other lineage II members, contributed to the stochastic assembly, as indicated by a high normalized stochasticity ratio (NST) value of 0.618. A total of 89.7 % and 5.6 % of the ASVs were defined as opportunists and generalists, respectively. Opportunists expand their taxonomic affiliation from Nitrospira lineages I, II, V, and grassland metagenome lineages to unknown lineages, and almost all specialists cannot be assigned to a known lineage or a subcluster. We observed that the NSTs for Opportunists and specialists were approximately 0.472 and 0.247, respectively, suggesting that the assembly of opportunists was less dominated by stochastic processes than was that of generalists, while the assembly of specialists highly relied on deterministic processes. Indeed, limited variation in the abundances of opportunists and specialists was significantly explained by the soil properties, agreeing that variable selection slightly contributed to Nitrospira community assembly. We also highlighted that each specialist with an unknown affiliation could be a new species or variant from Nitrospira in “specific” micro-environments, as indicated by the fact that one species occurred in only a few soil aggregate size fractions. The present study presents a case in which the stochastic process of Nitrospira community assembly in soil aggregates from two nearby ecosystems with mild environmental conditions could be explained by a high proportion of opportunists plus generalists and a few microhabitat specialists.

Invertebrates occurring in fruiting bodies of the pathogenic tinder fungus, Fomes fomentarius (Polyporales), in the different types of Polish protected forests

Bracket fungi are usually considered as a cause of economic losses, while they also offer specific microhabitats and have an impact on biodiversity. However, to date this topic has not been sufficiently studied. The aim of this article is to show how the diversity of invertebrate communities, viz. harvest spiders (Aranae, Opiliones), pseudoscorpions (Pseudoscorpionida), two groups of mites (Mesostigmata and Oribatida), springtails (Collembola), and insects (Insecta), inhabiting fruiting bodies of the tinder fungus, Fomes fomentarius, depend on specific characteristics of forests. Samples were collected in three locations: the Białowieża National Park (BNP) characterised by a high degree of forest naturalness, the Bieszczady National Park (BdNP), which was transformed by humans, but has been undergoing naturalisation for several decades, and the Karkonosze National Park affected by a large-scale forest dieback in the 1980s and which for years has been under strong tourist pressure. A total of 20 fruiting bodies of F. fomentarius were collected at each location. In total, 9,821 individuals of invertebrates belonging to 204 species were extracted. The most numerous group was Oribatida (6,595 individuals classified to 106 species), while the most numerous species was Carabodes femoralis (5,216 individuals). The study sites differed in the number of species (the highest one was observed in the BdNP, 115, and the lowest one in the KNP, 88) and number of individuals (the highest one was observed in BdNP, 4,285, and the lowest one in BNP, 1,595), as well as the number of individuals per species (the highest one was observed in the BdNP, 37.26 individuals per 1 species, and the lowest in the BNP, 15.79 individuals per 1 species). A NMDS analysis revealed that the inner distribution of the samples in each of the locations was similar in the case of mountain national parks (BdNP and KNP), while the invertebrate groupings from the BNP and KNP differed the most between one another. The multilevel pattern analysis showed different, specific invertebrate species for each study sites, e.g. Carabodes subarcticus for the BNP, Friesea mirabilis for the BdNP, Oribatella calcarata for the KNP and Dendrolaelaps pini for both mountain national parks. This study shows the uniqueness of invertebrate communities inhabiting fruiting bodies of F. fomentarius and confirms the positive role of this pathogenic fungi in shaping biodiversity. Key words: arthropods; bracket fungi; polypores; anthropopressure; natural forest

Burrow site selection in the Sungazer (Smaug giganteus): a threatened South African endemic lizard

ABSTRACT Elucidating factors that drive microhabitat selection in a species is important for informing the conservation management of the species. For species that use microhabitats as long-term refuge sites, selection pressures are likely to be strong because the microhabitat must fulfil their eco-physiological and life history requirements. Smaug giganteus (Sungazer) is a threatened (Vulnerable) cordylid lizard species in the highveld grasslands of South Africa – a key agricultural area in the country. Individuals dig burrows as refuges, which increases their sensitivity to habitat transformation. In addition, previous attempts to translocate populations have failed due to a lack of knowledge about their specific microhabitat requirements. We assessed microhabitat characteristics that may influence burrow site selection by measuring vegetation characteristics surrounding Sungazer burrows and comparing these to vegetation at randomly selected sites. We also recorded orientation, aspect, soil composition, and the presence of other animal dung. Sungazers selected sites with sparse vegetation cover, and where grass height was short, but had no preference for soil composition. There was no relationship between the presence of ungulate dung and the placement of Sungazer burrows. Most Sungazer burrows were orientated in a northerly direction on north-facing slopes, suggesting that burrow placement has thermoregulatory advantages. We recommend that to identify suitable sites for Sungazer translocations, landscapes are thoroughly surveyed with cognisance to the findings in this study, and that a soft-release translocation protocol follows to maximise translocation success.

Host-specific monogeneans parasitizing freshwater fish: The ecology and evolution of host-parasite associations.

Monogenea (Platyhelminthes), mainly gill and fin ectoparasites of fish, are often recognized as host specific and morphologically and ecologically diverse. These parasites exhibit high species diversity at the level of host species or individual fish specimens. Using case studies, especially those widely performed in Dactylogyrus parasitizing cyprinoid fish, this article presents current knowledge on the ecology and evolution of congeneric gill monogeneans. The important aspects of the ecology of congeneric monogeneans are highlighted, in particular: host specificity expressed at several host levels (from strict specificity to phylogenetic specificity), microhabitat specificity expressed by restricted positions on fish gills to facilitate intraspecific mating, and the link between microhabitat preference and morphological adaptation (i.e., sclerotized structures of the haptor) or reproductive isolation. From the evolutionary perspective, this study focused on the processes of the speciation and diversification of congeneric monogeneans, highlighting the role of host switch as the most prominent coevolutionary event, accompanied in some cases mostly by intrahost speciation or cospeciation, as revealed by cophylogenetic studies. Here, important knowledge on evolutionary patterns of host specificity, microhabitat specificity, and morphological adaptation is presented. Host-specific monogeneans may represent an important tool for studying the historical biogeography of their hosts. Specifically, in the case of freshwater fish hosts exhibiting disjunctive distribution, they reflect both historical and contemporary contacts. The role of host-specific congeneric monogeneans in revealing historical intercontinental and intracontinental contacts between freshwater fish is highlighted. Finally, the importance of the role of genetic coadaptation, limiting the presence of host-specific monogeneans in hybrid fish, is emphasized.

Microbial diversity and potential functional dynamics within the rhizocompartments of Dendrobium huoshanense.

Understanding the microbial diversity and potential functional dynamics within the rhizocompartments of Dendrobium huoshanense is crucial for unraveling the plant-microbe interactions that influence its medicinal properties. This study is the first to characterize the microbiome associated with the rhizocompartments of D. huoshanense, including its cultivation medium, rhizosphere, rhizoplane, and root endosphere, using high-throughput sequencing and subsequent bioinformatic analysis. Bacterial phylogenetic diversity was significantly higher in the endosphere than in the rhizosphere, while fungal α-diversity significantly decreased from the cultivation medium to the endosphere. Both bacterial and fungal niche widths decreased from the cultivation medium to the endosphere. β-Diversity analysis revealed distinct spatial patterns in both bacterial and fungal communities across the rhizocompartments, with the most pronounced differences between the cultivation medium and the endosphere. Taxonomically, Proteobacteria and Ascomycota were predominant in the endosphere for bacterial and fungal communities, respectively. Functional predictions showed significant enrichment of pathways related to xenobiotics biodegradation, lipid metabolism, and nitrogen fixation in the endosphere, while functions associated with plant pathogens and saprotrophs were significantly reduced. The results indicate a shift from generalist to specialist microbes from the cultivation medium to the endosphere, suggesting that D. huoshanense exerts strong selective pressure for endophytic fungi. Interestingly, a high proportion of fungi with unknown functions were found in the endosphere, highlighting an area for further research regarding the medicinal efficacy of D. huoshanense. Overall, this study provides foundational data for understanding the adaptive evolution of these microbial communities in response to specific microhabitats.

The influence of environmental context on community composition in artificial rockpools associated with seawalls

Artificial structures have become widespread features of coastal marine environments, and will likely proliferate further over the coming decades. These constitute new hard substrata in the marine environment which provide a fundamentally different habitat than natural shores. Eco-engineering solutions aim to ameliorate these differences by combining ecological knowledge and engineering criteria in the construction and modification of artificial substrata. Vertipools™ are artificial bolt-on rockpools intended for deployment on seawalls, where they have been shown to provide biodiversity benefits. In this study, a total of 32 Vertipools were retrofitted on eight seawalls in different environmental contexts (estuarine vs marine and urban vs rural) along the Irish Sea coastline, and were exposed to the environment for a period of two years. After two years, there were no differences in species richness, species-abundance distributions, diversity, or community composition between the specific environmental contexts examined here. Site-level variation was significant, and communities on Vertipools deployed in marine contexts were more variable in general than those in estuarine contexts. Community composition differed significantly between structural sections of the Vertipools, indicating that different sections provide specific microhabitats for colonisation. This study indicates that Vertipools provide biodiversity benefits in a variety of environmental contexts, and therefore are broadly viable as an eco-engineering solution.

Time will tell: Taxonomic and functional diversity of monilophyte ferns in native forests and abandoned silviculture systems

AbstractDifferent forest systems can influence the function, traits, diversity, and distribution of ferns. By comparing ferns based on their functional traits, we can explore how species loss affects functional diversity, and consequently alter the forest ecosystem. We investigated the impact of abandoned silviculture on fern diversity (taxonomic and functional) and abundance. Our hypothesis suggests a positive effect of nutrients and soil humidity in native forests, while canopy openness in silviculture has a negative effect on monilophyte diversity. This study was conducted in three sites of native forest and three sites of Pinus silviculture. Each site was subdivided into three areas, with three plots per area, resulting in 54 plots (3 sites × 3 areas × 3 plots × 2 forest types). Each plot covered an area of 100 m2 (10 m × 10 m; 5400 m2 in total). In each plot, we estimated abundance, functional attributes (richness, evenness, divergence, and dispersion) based on leaf thickness, leaf width, petiole length, stem length, leaf division, sori shape, indusium presence, and taxonomic diversity. Results indicate that native forest exhibit higher taxonomic and functional diversity (richness—Fric) compared to abandoned Pinus plantations, which may be attributed to high habitat diversity and species specialization in specific microhabitats. In silviculture, diversity homogenization leads to an increase in the redundancy of functional attributes (evenness—Feve), resulting in the filtering out of similar organisms. Abiotic factors such as light and canopy openness negatively influence plant establishment and growth, leading to a decrease in leaf division and indusium presence/absence (by CWMs), supporting niche complementarity theory in natural forest and mass ratio theory in silviculture. Our findings highlight the enduring negative impact of silviculture, even after 20 years, on both the taxonomic and functional diversity of monilophytes, underscoring the crucial role of native forests in preserving fern diversity.

Infection with Trypanosoma Cruzi Chagas and Characterization of Human Habitats of Triatoma Picturata (Usinger) in Western Mexico.

Chagas disease is one of the most important vector-borne diseases in Latin America. Triatoma picturata (Usinger), distributed in western Mexico, is one of the most important vectors of Trypanosoma cruzi Chagas. Knowing the type and materials used for building homes could lead to improved methods for controlling triatomines by focusing efforts on controlling every species of triatomine in its specific microhabitat. Houses in three studied localities of western Mexico that harbored T. picturata were characterized, as well as two entomological indices. Infestation Index values varied from 10.8% to 51.9% in the three localities, whereas Natural Infection Index values varied from 18.1% to 35.2%. Characteristics of houses invaded by T. picturata also varied. In Juan Gil Preciado, with the highest Entomological Index values, most houses were built of adobe walls with a roof of clay tiles and a dirt floor, and included the presence of domestic animals. Our data indicate that the potential risk of infection with T. cruzi differs markedly for inhabitants of the three studied localities, which demonstrates the importance of studying local populations of triatomines. Our study should contribute to decision-making regarding triatomine control efforts by providing profiles of houses that are more susceptible to triatomine invasion.

Species-specific gill’s microbiome of eight crab species with different breathing adaptations

Transitions to physically different environments, such as the water-to-land transition, proved to be the main drivers of relevant evolutionary events. Brachyuran crabs evolved remarkable morphological, behavioral, and physiological adaptations to terrestrial life. Terrestrial species evolved new respiratory structures devoted to replace or support the gills, a multifunctional organ devoted to gas exchanges, ion-regulation and nitrogen excretion. It was hypothesized that microorganisms associated with respiratory apparatus could have facilitated the processes of osmoregulation, respiration, and elimination of metabolites along this evolutionary transition. To test if crab species with different breathing adaptations may host similar microbial communities on their gills, we performed a comparative targeted-metagenomic analysis, selecting two marine and six terrestrial crabs belonging to different families and characterised by different breathing adaptations. We analysed anterior and posterior gills separately according to their different and specific roles. Regardless of their terrestrial or marine adaptations, microbial assemblages were strongly species-specific indicating a non-random association between the host and its microbiome. Significant differences were found in only two terrestrial species when considering posterior vs. anterior gills, without any association with species-specific respiratory adaptations. Our results suggest that all the selected species are strongly adapted to the ecological niche and specific micro-habitat they colonise.

Discerning structure versus speciation in phylogeographic analysis of Seepage Salamanders (Desmognathus aeneus) using demography, environment, geography, and phenotype.

Numerous mechanisms can drive speciation, including isolation by adaptation, distance, and environment. These forces can promote genetic and phenotypic differentiation of local populations, the formation of phylogeographic lineages, and ultimately, completed speciation. However, conceptually similar mechanisms may also result in stabilizing rather than diversifying selection, leading to lineage integration and the long-term persistence of population structure within genetically cohesive species. Processes that drive the formation and maintenance of geographic genetic diversity while facilitating high rates of migration and limiting phenotypic differentiation may thereby result in population genetic structure that is not accompanied by reproductive isolation. We suggest that this framework can be applied more broadly to address the classic dilemma of "structure" versus "species" when evaluating phylogeographic diversity, unifying population genetics, species delimitation, and the underlying study of speciation. We demonstrate one such instance in the Seepage Salamander (Desmognathus aeneus) from the southeastern United States. Recent studies estimated up to 6.3% mitochondrial divergence and four phylogenomic lineages with broad admixture across geographic hybrid zones, which could potentially represent distinct species supported by our species-delimitation analyses. However, while limited dispersal promotes substantial isolation by distance, microhabitat specificity appears to yield stabilizing selection on a single, uniform, ecologically mediated phenotype. As a result, climatic cycles promote recurrent contact between lineages and repeated instances of high migration through time. Subsequent hybridization is apparently not counteracted by adaptive differentiation limiting introgression, leaving a single unified species with deeply divergent phylogeographic lineages that nonetheless do not appear to represent incipient species.

Multi-omics reveals largely distinct transcript- and protein-level responses to the environment in an intertidal mussel.

Organismal responses to stressful environments are influenced by numerous transcript- and protein-level mechanisms, and the relationships between expression changes at these levels are not always straightforward. Here, we used paired transcriptomic and proteomic datasets from two previous studies from gill of the California mussel, Mytilus californianus, to explore how simultaneous transcript and protein abundance patterns may diverge under different environmental scenarios. Field-acclimatized mussels were sampled from two disparate intertidal sites; individuals from one site were subjected to three further treatments (common garden, low-intertidal or high-intertidal outplant) that vary in temperature and feeding time. Assessing 1519 genes shared between the two datasets revealed that both transcript and protein expression patterns differentiated the treatments at a global level, despite numerous underlying discrepancies. There were far more instances of differential expression between treatments in transcript only (1451) or protein only (226) than of the two levels shifting expression concordantly (68 instances). Upregulated expression of cilium-associated transcripts (likely related to feeding) was associated with relatively benign field treatments. In the most stressful treatment, transcripts, but not proteins, for several molecular chaperones (including heat shock proteins and endoplasmic reticulum chaperones) were more abundant, consistent with a threshold model for induction of translation of constitutively available mRNAs. Overall, these results suggest that the relative importance of transcript- and protein-level regulation (translation and/or turnover) differs among cellular functions and across specific microhabitats or environmental contexts. Furthermore, the degree of concordance between transcript and protein expression can vary across benign versus acutely stressful environmental conditions.

Thermal biology of Lanthanotus borneensis (Lanthanotidae) in Sarawak, Borneo

Abstract Lanthanotus borneensis, the Bornean earless monitor, is a monotypic member of the family Lanthanotidae, and restricted to the island of Borneo. Little has been published on its field ecology. This study investigated aspects of its thermal biology through an analysis of surface body temperatures of free ranging individuals against corresponding environmental temperatures, in order to explore aspects of microhabitat utilisation in relation to thermoregulation. A generalised linear mixed model shows significant effect of air and substrate temperatures, but not of water temperature. Further, the fixed effects of substrate temperature (coefficient estimate 0.396; ) versus ambient temperature (0.264; ), is suggestive of thigmothermy as the primary mode of thermoregulation. The species does not appear to utilise specific microhabitat structures to thermoregulate, the results of these observations suggesting that it is a thermoconformer.

Toxic, genotoxic, mutagenic, and bioaccumulative effects of metal mixture from settleable particulate matter on American bullfrog tadpoles (Lithobates catesbeianus)

Amphibians are more susceptible to environmental stressors than other vertebrates due to their semipermeable skin and physiological adaptations to living in very specific microhabitats. Therefore, the aim of the present study was to investigate the effects of a metal mixture from settleable particulate matter (SePM) released from metallurgical industries on Lithobates catesbeianus tadpoles. Endpoints analyzed included metal bioconcentration, morphological (biometrical indices), hematological parameters (hemoglobin and blood cell count), and erythrocyte DNA damage (genotoxicity and mutagenicity). American bullfrog tadpoles (Gosner's stage 25) were kept under control condition (no contaminant addition) or exposed to a sub-lethal and environmentally relevant concentration (1 g.L−1) of SePM for 96 h. Tadpoles exposed to SePM exhibited elevated whole blood levels of Fe56, AL, Sn, Pb, Zn, Cr, Cu, Ti, Rb, V, Ce, La, Ag, As. SePM-exposed tadpoles showed a significant decrease in condition factor (12%) and increases in hepatosomatic index (25%), hemoglobin concentration (17%), and total leukocytes (82%), thrombocytes (90%), and monocytes (78%) abundance. In addition, exposed tadpoles showed higher MN and ENAs (340 and 140%, respectively) frequencies, and erythrocyte DNA damage with approximately 1.2- to 1.8-fold increases in comet parameters. Taken together, these results suggest that the multimetal mixture found in SePM is potentially genotoxic and mutagenic to L. catesbeianus tadpoles, induces stress associated with hematological changes, and negatively affects growth. Although such contamination occurs at sublethal levels, regulatory standards are needed to control the emission of SePM and protect amphibian populations.

Cohabitation with aggressive hosts: description of a new microhisterid species in nests of a ponerine ant with ecological notes

A new clown beetle species, Bacanius neoponerae, is described from Mexican nests of the arboreal ponerine ant Neoponera villosa found in the tank bromeliad Aechmea bracteata. Adult beetles were found in brood chambers or inner refuse piles, but also outside the ant nests, in decaying organic matter between the bromeliad leaves. No direct interactions between ants and microhisterid beetles could be observed. Several lines of evidence suggest a close relationship either with the ants, specific microhabitats within the ant nests or the bromeliads. Sample site elevation, colony size, monthly rainfall and collecting site were the main variables predicting the association. Almost half of the N. villosa colonies were associated with the microhisterids, and larger colonies favored their presence, especially during the driest months of the year. Two specimens were found in a nest of another ant species, Camponotus atriceps, also inhabiting A. bracteata. The new species is the seventh of the genus Bacanius reported from Mexico. This is the second time a species of this genus is associated with ants, and the fourth record of a histerid beetle cohabiting with ponerine ants. The small size of these beetles and their very protective body structure may facilitate their cohabitation with such aggressive hosts.