David Friedrich Weinland

ABSTRACTAimThis study sets out to understand the variability in larval traits of dispersive life stages of a famous invader, the European shore crab Carcinus maenas, in its native distribution range.LocationNorth East Atlantic coast from the Norwegian Arctic to the southern European distribution limit of C. maenas in Southern Spain.TaxonEuropean shore crab Carcinus maenas (Crustacea, Decapoda).MethodsWe quantified latitudinal patterns in larval body mass, elemental composition (C and N content), and thermal tolerance of the first larval stage. We collected crabs from four populations spanning 25° of latitude (Vigo in Northern Spain; Bergen, Trondheim, and Bodø in Norway) and reanalysed published and unpublished data of body mass and elemental composition of additional populations from Germany, Wales, France, and Southern Spain. Furthermore, we used two laboratory experiments to test the thermal tolerance limits of the first larval stage from Vigo and the Norwegian populations. In the first experiment, we reared larvae from hatching to Zoea II at seven temperatures (9°C–27°C) and from hatching to LT50 at 6°C. In the second experiment, we exposed freshly hatched larvae acutely to increasing or decreasing temperatures (up to 40°C and down to 3°C).ResultsAcross the entire European range, we found a substantial increase in dry mass and carbon and nitrogen content of freshly hatched larvae with latitude. Norwegian populations exhibited higher survival at 9°C than the Vigo population. Furthermore, LT50 at 6°C increased from South to North. All populations showed high survival in the range 12°C–24°C but low survival at 27°C.Main ConclusionsLarval tolerance quantified by using survival to Zoea II is not clearly related to the tolerance quantified with the acute experiments, indicating that each method assesses different aspects of thermal tolerance. Tolerance to low temperature correlated positively to tolerance to high temperature, suggesting that variation among females in larval responses reflects a general physiological quality rather than trade‐offs. We provide evidence for potentially adaptive variations in larval body mass and thermal tolerance across a latitudinal gradient for C. maenas.

Dispersal ability may play a major role in determining whether a species will persist under climate change. We used models of dispersal, employing a wide range of intrinsic species-specific dispersal factors, in conjunction with ecological niche models (ENM) and climate predictions to simulate whether distributions of North American cold-adapted amphibians will increase or decrease, and which aspects of dispersal most influence this prediction. We used ENM values as a proxy for habitat suitability, predicted a changing climate under three shared socio-economic pathways (SSP2-4.5, SSP3-7.0, and SSP5-8.5) representing three carbon emission scenarios, and conducted a sensitivity analysis on the effect of dispersal factors on range dynamics. We then used simulations focused only on the southern edge of ranges to determine the likelihood of individuals colonizing towards the core. Predicted range shifts depended on emission scenario, dispersal factors, and species’ initial geography. Inclusion of dispersal parameters was critical in predicting range shifts, in particular for high carbon-emission scenarios where contraction was more likely than expansion, although specific responses varied with species initial geography. Dispersal distance, probability of dispersal, and long-distance dispersal were often the most important parameters for predicting final range size. Similarly, dispersal parameters results in complete loss to complete emigration of southern range individuals towards the core. These models predict that for some species in the more rapid warming scenarios, translocation efforts will be needed to mitigate potential loss of genetic variation at the southern edges and the overall size of the species’ ranges unless carbon emissions are reduced.

Island ecosystems have significant conservation value owing to their higher endemic biotas. Moreover, studies of regional communities that compare differences in species composition (species dissimilarity) among islands and the mainland suggest that community assembly on islands is different from that on the mainland. However, the uniqueness of island biotic assembly has been little studied at the global scale, nor have phylogenetic information or alien species been considered in these patterns. We evaluate taxonomic and phylogenetic change from one community to the next, focusing on differences in species composition between mainland-mainland (M-M) pairs compared to differences between mainland-island pairs (M-I) and between island-island pairs (I-I), using herpetofauna on islands and adjacent mainland areas worldwide. Our analyses detect greater taxonomic and phylogenetic dissimilarity for M-I and I-I comparisons than predicted by M-M model, indicating different island herpetofauna assembly patterns compared with mainland counterparts across the world. However, this higher M-I dissimilarity has been significantly decreased after considering alien species. Our results provide global evidence on the importance of island biodiversity conservation from the aspect of both the taxonomic and phylogenetic uniqueness of island biotic assembly.

Amphibians are the most threatened group of vertebrates and are in dire need of conservation intervention to ensure their continued survival. They exhibit unique features including a high diversity of reproductive strategies, permeable and specialized skin capable of producing toxins and antimicrobial compounds, multiple genetic mechanisms of sex determination and in some lineages, the ability to regenerate limbs and organs. Although genomic approaches would shed light on these unique traits and aid conservation, sequencing and assembly of amphibian genomes has lagged behind other taxa due to their comparatively large genome sizes. Fortunately, the development of long‐read sequencing technologies and initiatives has led to a recent burst of new amphibian genome assemblies. Although growing, the field of amphibian genomics suffers from the lack of annotation resources, tools for working with challenging genomes and lack of high‐quality assemblies in multiple clades of amphibians. Here, we analyse 51 publicly available amphibian genomes to evaluate their usefulness for functional genomics research. We report considerable variation in genome assembly quality and completeness and report some of the highest transposable element and repeat contents of any vertebrate. Additionally, we detected an association between transposable element content and climatic variables. Our analysis provides evidence of conserved genome synteny despite the long divergence times of this group, but we also highlight inconsistencies in chromosome naming and orientation across genome assemblies. We discuss sequencing gaps in the phylogeny and suggest key targets for future sequencing endeavours. Finally, we propose increased investment in amphibian genomics research to promote their conservation.

Understanding the distribution of rare species is important for conservation prioritisation. Traditionally, museums and other research institutions have served as depositories for specimens and biodiversity information. However, estimating abundance from these sources is challenging due to spatiotemporally biased collection methods. For instance, large‐bodied reptiles that are found near research institutions or in popular, easily accessible sites tend to be overrepresented in collections compared to smaller species found in remote areas. Recently, a substantial number of observations have been amassed through citizen (or community) science initiatives, which are invaluable for monitoring purposes. Given the unstructured nature of this sampling, these datasets are often affected by biases, such as taxonomic, spatial and temporal preferences. Therefore, analysing data from these two sources can lead to different abundance estimates. This study compiled data on Brazilian reptile species from the Global Information Biodiversity Facility (GBIF). It employed a community‐ecology approach to analyse data from research institutions and citizen science initiatives, separately and collectively, to assess taxonomic and spatial species coverage and predict species rarity. Using a 1‐degree hexagonal grid, we analysed the spatial distribution of reptile communities and calculated rarity indices for 754 reptile species. Our findings reveal that 87 species were exclusively recorded in the citizen science subset, while 212 were recorded only by research institutions. The number of observations per species in the citizen science data followed a Gambin distribution, which aligns with the expected pattern of abundance in natural communities, unlike the data from research institutions. This suggests that citizen science data may be a more accurate source for estimating species abundance and rarity. The discrepancies in rarity classifications between the datasets were likely due to differences in sample size and potentially other sampling parameters. Nevertheless, combining data collected by both research institutions and citizen science initiatives can help to fill knowledge gaps in reptile species occurrence, thus enhancing the foundation for conservation efforts on a national scale.

Understanding species from an ecological and phylogenetic perspective facilitates an understanding of their conservation status in relation to the changing world. The frog genus Pelophylax is among the largest in terms of amphibian biomass in the Palearctic, but species have not been thoroughly studied at the Asian continental scale. The phylogeographic relationship, behavioural ecology, and ecological requirements within the genus need clarification, despite generally good local coverage. Here, for the first time, we conducted a literature review focused on phylogeography and behavioural ecology, supported by ecological niche modelling of twelve Asian Pelophylax lineages. Finally, we compiled the known threats for each of the lineages. We first determined the presence of twelve species and species-candidate lineages. In terms of behavioural ecology, the main difference among lineages is the time to metamorphosis and the time to reach sexual maturity. The ecological models highlighted a match between the known presence of each clade and their suitable habitat and highlighted the Syr Darya drainage on the eastern shore of the Caspian Sea for the non-described Pelophylax “Syr Darya lineage”. Finally, we highlighted the greatest variation among lineages in terms of threats, as some lineages are threatened by numerous factors, whereas others are expanding.

Aim Ecological niche‐based models (ENM) frequently rely on bioclimatic variables (BioV) to reconstruct biogeographic scenarios for species evolution, ignoring mechanistic relations. We tested if climatic predictors relevant to species hydric and thermal physiology better proximate distribution patterns and support location of Pleistocene refugia derived from phylogeographic studies.LocationThe Western Palaearctic.TaxonVipera berus and Zootoca vivipara, two cold‐adapted species.MethodsWe used two sets of variables, that is physiologically meaningful climatic variables (PMV) and BioV, in a multi‐algorithm ENM approach, to compare their ability to predict current and Last Glacial Maximum (LGM) species ranges. We estimated current and LGM permafrost extent to address spatially the cold hardiness dissimilarity between both species.ResultsPMV explained more accurately the current distribution of these two cold‐adapted species and identified the importance of summer temperature and solar radiation that constrain activity in cold habitats. PMV also provide a better insight than BioV predictors on LGM distribution. By including notably, the permafrost extent, PMV‐based models gave parsimonious putative arrangement and validity of refugia for each clade and subclade in accordance with phylogeographic data. Northern refugia were also identified from 48 to 52° N for V. berus and from 50 to 54° N for Z. vivipara.Main ConclusionsOur hybrid approach based on PMV generated more realistic predictions for both current (biogeographical validation) and past distributions (phylogeographic validation). By combining constraints during the activity period (summer climatic niche) and those inherent to the wintering period (freeze tolerance), we managed to identify glacial refuges in agreement with phylogeographic hypotheses concerning post‐glacial routes and colonization scenarios.

Aim The evolutionary interactions between western spadefoot toads (genus Spea) represent a textbook example of character displacement, facilitated by dietary specialization of one Spea species on fairy shrimp (Anostraca) when all three co‐occur. The aim of this study is to understand the covariation between predator (Spea) and prey (Anostraca) range shifts in response to climate change oscillations, and whether biotic interactions can be used to project species distribution models on different time scales when studying species with dietary specialization. Taxon: Amphibia: Spea spp. and Crustacea: Anostraca.LocationNorth America.MethodsUsing multiple modelling techniques, we first estimated the potential distribution of central and western North American fairy shrimp species (Crustacea: Anostraca) and two western spadefoot toad species (Spea bombifrons and Spea multiplicata). We then created a shrimp species richness map by aggregating individual species estimates. Third, we studied the relationship between the probability of spadefoot toad presence and fairy shrimp species richness during the present and Last Glacial Maximum conditions. Finally, we estimated the strength and direction of the co‐occurrence between spadefoot toads and fairy shrimp sampled at the level of entire predicted range and at the regional level (allopatric and sympatric).ResultsFirst, the same abiotic environmental variables shape spadefoot toad and fairy shrimp species' distributions in central and western North America across time. Second, areas of sympatry of Spea bombifrons and Spea multiplicata correspond with dry conditions and higher shrimp richness. Finally, the spatial patterns of predator–prey co‐occurrence are highly variable across geography, forming a spatial mosaic over the species' ranges.Main ConclusionPredator–prey relationships form a spatial mosaic across geography and species ranges. Including biotic interactions into species distribution estimates for organisms with dietary specialization is highly recommended. Biotic interactions can be projected across different time frames for organisms with dietary specialization as they are likely conserved.

The maintenance, restoration, and improvement of habitat structure are critical for biodiversity conservation. Under this context, studies assessing habitat connectivity become essential, especially those focused on anthropized regions holding high species richness. We calculated the habitat connectivity of four species of insectivorous bats with different dispersal capacity and habitat preferences in a highly anthropized region in central Mexico, Idionycteris phyllotis and Myotis thysanodes , with a high dispersal capacity and forest-dependency, and Eptesicus fuscus with a low dispersal capacity, and Tadarida brasiliensis with a high dispersal capacity, as the more tolerant bat species to anthropogenic disturbance. We developed niche-based species distribution models to identify suitable habitat patches for each species. We then assessed habitat connectivity and the importance of suitable habitat patches for maintaining connectivity using a graph theory approach. Our results showed that forest dependency was most important than dispersal capacity for connectivity. We also found that the Iztaccíhuatl-Popocatépetl mountain, a National Park comprising 4.2% of natural vegetation in the study area, was the most critical patch for maintaining connectivity for most of the study species. Our study demonstrates the importance of conserving the remnants of natural vegetation for maintaining habitat connectivity within a fragmented landscape and demonstrates the importance of conserving protected areas as well as other remnants of vegetation for the maintenance of habitat connectivity within a fragmented landscape.

Aim To investigate the drivers of intra-specific genetic diversity in centipedes, a group of ancient predatory soil arthropods. Location Asia, Australasia and Europe. Time Period Present. Major Taxa Studied Centipedes (Class: Chilopoda). Methods We assembled a database of 1245 mitochondrial cytochrome c oxidase subunit I sequences representing 128 centipede species from all five orders of Chilopoda. This sequence dataset was used to estimate genetic diversity for centipede species and compare its distribution with estimates from other arthropod groups. We studied the variation in centipede genetic diversity with species traits and biogeography using a beta regression framework, controlling for the effect of shared evolutionary history within a family. Results A wide variation in genetic diversity across centipede species (0–0.1713) falls towards the higher end of values among arthropods. Overall, 27.57% of the variation in mitochondrial COI genetic diversity in centipedes was explained by a combination of predictors related to life history and biogeography. Genetic diversity decreased with body size and latitudinal position of sampled localities, was greater in species showing maternal care and increased with geographic distance among conspecifics. Main Conclusions Centipedes fall towards the higher end of genetic diversity among arthropods, which may be related to their long evolutionary history and low dispersal ability. In centipedes, the negative association of body size with genetic diversity may be mediated by its influence on local abundance or the influence of ecological strategy on long-term population history. Species with maternal care had higher genetic diversity, which goes against expectations and needs further scrutiny. Hemispheric differences in genetic diversity can be due to historic climatic stability and lower seasonality in the southern hemisphere. Overall, we find that despite the differences in mean genetic diversity among animals, similar processes related to life-history strategy and biogeography are associated with the variation within them.