From biomarkers to community composition: Negative effects of UV/chlorine-treated reclaimed urban wastewater on freshwater biota

The use of urban wastewater reclaimed water has recently increased across the globe to restore stream environmental flows and mitigate the effects of water scarcity. Reclaimed water is disinfected using different treatments, but their effects into the receiving rivers are little studied. Physiological bioassays and biomarkers can detect sub-lethal effects on target species, but do not provide information on changes in community structure. In contrast, official monitoring programs use community structure information but often at coarse taxonomic resolution level that may fail to detect species level impacts. Here, we combined commonly used biomonitoring approaches from organism physiology to community species composition to scan a broad range of effects of disinfection of reclaimed water by UV-light only and both UV/chlorine on the biota. We (1) performed bioassays in one laboratory species (water flea Daphnia magna) and measured biomarkers in two wild species (caddisfly Hydropsyche exocellata and the barbel Luciobarbus graellsii), (2) calculated standard indices of biotic quality (IBQ) for diatoms, benthic macroinvertebrates, and fishes, and (3) analysed community species composition of eukaryotes determined by Cytochrome Oxidase C subunit I (cox1) metabarcoding. Only the UV/chlorine treatment caused significant changes in feeding rates of D. magna and reduced antioxidant defenses, increased anaerobic metabolism and altered the levels of lipid peroxidiation in H. exocellata. However, inputs of reclaimed water were significantly associated with a greater proportion of circulating neutrophils and LG-PAS cells in L. graellsii. Despite IBQ did not discriminate between the two water treatments, metabarcoding data detected community composition changes upon exposure to UV/chlorine reclaimed water. Overall, despite the effects of UV/chlorine-treated water were transient, our study suggests that UV-light treated is less harmful for freshwater biota than UV/chlorine-treated reclaimed water, but those effects depend of the organizational level.

The Non-Dereliction in Evolution: Trophic Specialisation Drives Convergence in the Radiation of Red Devil Spiders (Araneae: Dysderidae) in the Canary Islands

Natural selection plays a key role in deterministic evolution, as clearly illustrated by the multiple cases of repeated evolution of ecomorphological characters observed in adaptive radiations. Unlike most spiders, Dysdera species display a high variability of cheliceral morphologies, which has been suggested to reflect different levels of specialization to feed on isopods. In this study, we integrate geometric morphometrics and experimental trials with a fully resolved phylogeny of the highly diverse endemic species from the Canary Islands to 1) quantitatively delimit the different cheliceral morphotypes present in the archipelago, 2) test their association with trophic specialization, as reported for continental species, 3) reconstruct the evolution of these ecomorphs throughout the diversification of the group, 4) test the hypothesis of convergent evolution of the different morphotypes, and 5) examine whether specialization constitutes a case of evolutionary irreversibility in this group. We show the existence of 9 cheliceral morphotypes and uncovered their significance for trophic ecology. Further, we demonstrate that similar ecomorphs evolved multiple times in the archipelago, providing a novel study system to explain how convergent evolution and irreversibility due to specialization may be combined to shape phenotypic diversification in adaptive radiations.

The Vitruvian spider: Segmenting and integrating over different body parts to describe ecophenotypic variation

Understanding what drives the existing phenotypic variability has been a major topic of interest for biologists for generations. However, the study of the phenotype may not be straightforward. Indeed, organisms may be interpreted as composite objects, comprising different ecophenotypic traits, which are neither necessarily independent from each other nor do they respond to the same evolutionary pressures. For this reason, a deep biological understanding of the focal organism is essential for any morphological analysis. The spider genus Dysdera provides a particularly well-suited system for setting up protocols for morphological analyses that encompass a suit of morphological structures in any nonmodel system. This genus has undergone a remarkable diversification in the Canary Islands, where different species perform different ecological roles, exhibiting different levels of trophic specialization or troglomorphic adaptations, which translate into a remarkable interspecific morphological variability. Here, we seek to develop a broad guide, of which morphological characters must be considered, to study the effect of different ecological pressures in spiders and propose a general workflow that will be useful whenever researchers set out to investigate variation in the body plans of different organisms, with data sets comprising a set of morphological traits. We use geometric morphometric methods to quantify variation in different body structures, all of them with diverse phenotypic modifications in their chelicera, prosoma, and legs. We explore the effect of analyzing different combined landmark (LM) configurations of these characters and the degree of morphological integration that they exhibit. Our results suggest that different LM configurations of each of these body parts exhibit a higher degree of integration compared to LM configurations from different structures and that the analysis of each of these body parts captures different aspects of morphological variation, potentially related to different ecological factors.

Life-history traits drive spatial genetic structuring in Dinaric cave spiders

The subterranean ecosystem exerts strong selection pressures on the organisms that thrive in it. In response, obligate cave-dwellers have developed a series of morphological, physiological, and behavioral adaptations, such as eye reduction, appendage elongation, low metabolic rates or intermittent activity patterns, collectively referred to as troglomorphism. Traditionally, studies on cave organisms have been hampered by the difficulty of sampling (i.e., small population sizes, temporal heterogeneity in specimen occurrence, challenges imposed by the difficult-to-access nature of caves). Here, we circumvent this limitation by implementing a museomics approach. Specifically, we aim at comparing the genetic population structures of five cave spider species demonstrating contrasting life histories and levels of troglomorphism across different caves in the northern Dinarides (Balkans, Europe). We applied a genome-wide hybridization-capture approach (i.e., HyRAD) to capture DNA from 117 historical samples. By comparing the population genetic structures among five species and by studying isolation by distance, we identified deeper population structuring and more pronounced patterns of isolation by distance in the highly troglomorphic Parastalita stygia and Stalita pretneri ground dwellers, while the three web-building Troglohyphantes species, two of which can occasionally be found in surface habitats, showed less structured populations compatible with higher dispersal ability. The spatial distribution of genetic groups revealed common phylogeographic breaks among lineages across the studied species, which hint at the importance of environmental features in driving dispersal potential and shaping underground diversity.

Repeated colonization, adaptive radiation and convergent evolution in the sheet-weaving spiders (Linyphiidae) of the south Pacific Archipelago of Juan Fernandez

We report on the colonization and diversification of linyphiid spiders in the Pacific oceanic archipelago of Juan Fernandez. About 50 spider species occur naturally in these islands, most of them endemic and about half of them are linyphiids. Linyphiidae includes no fewer than 15 species of Laminacauda and three of Neomaso (with several additional undescribed species in the latter genus), all of them single island endemics. There are three additional linyphiid endemic genera, two monotypic and one, Juanfernandezia, with two species. Unlike the rather uniform somatic morphology and small ground sheet webs of the continental Laminacauda and Neomaso species, the Juan Fernandez endemics exhibit morphological features and life history traits that are very rare or unknown in any other linyphiids. A multi-locus phylogenetic analysis confirms at least five independent Juan Fernandez colonizations of Linyphiidae, two within the same genus, and three of which underwent subsequent local diversification. Different calibrations suggest alternative colonization timelines, some at odds with island ages, but all agree on similar diversification timings of the endemic lineages. Rare phenotypic traits (e.g. gigantism, massive chelicerae or elongated legs) evolved multiple times independently within the islands. Based on the remarkable levels of eco-phenotypic differentiation in locally diversified species showing densely packed distributions, we propose that Laminacauda, and probably Neomaso, constitute a case of adaptive radiation.

Converging on the orb: denser taxon sampling elucidates spider phylogeny and new analytical methods support repeated evolution of the orb web

High throughput sequencing and phylogenomic analyses focusing on relationships among spiders have both reinforced and upturned long-standing hypotheses. Likewise, the evolution of spider webs-perhaps their most emblematic attribute-is being understood in new ways. With a matrix including 272 spider species and close arachnid relatives, we analyze and evaluate the relationships among these lineages using a variety of orthology assessment methods, occupancy thresholds, tree inference methods and support metrics. Our analyses include families not previously sampled in transcriptomic analyses, such as Symphytognathidae, the only araneoid family absent in such prior works. We find support for the major established spider lineages, including Mygalomorphae, Araneomorphae, Synspermiata, Palpimanoidea, Araneoidea and the Retrolateral Tibial Apophysis Clade, as well as the uloborids, deinopids, oecobiids and hersiliids Grade. Resulting trees are evaluated using bootstrapping, Shimodaira-Hasegawa approximate likelihood ratio test, local posterior probabilities and concordance factors. Using structured Markov models to assess the evolution of spider webs while accounting for hierarchically nested traits, we find multiple convergent occurrences of the orb web across the spider tree-of-life. Overall, we provide the most comprehensive spider tree-of-life to date using transcriptomic data and use new methods to explore controversial issues of web evolution, including the origins and multiple losses of the orb web.

The chromosome-scale assembly of the Canary Islands endemic spider Dysdera silvatica (Arachnida, Araneae) sheds light on the origin and genome structure of chemoreceptor gene families in chelicerates

Here, we present the chromosome-level genome assembly of Dysdera silvatica Schmidt, 1981, a nocturnal ground-dwelling spider endemic from the Canary Islands. The genus Dysdera has undergone a remarkable diversification in this archipelago mostly associated with shifts in the level of trophic specialization, becoming an excellent model to study the genomic drivers of adaptive radiations. The new assembly (1.37 Gb; scaffold N50 of 174.2 Mb), was performed using the chromosome conformation capture scaffolding technique, represents a continuity improvement of more than 4500 times with respect to the previous version. The seven largest scaffolds or pseudochromosomes, which cover 87% of the total assembly size, probably correspond with the seven chromosomes of the karyotype of this species, including a characteristic large X chromosome. To illustrate the value of this new resource we performed a comprehensive analysis of the two major arthropod chemoreceptor gene families (i.e., gustatory and ionotropic receptors). We identified 545 chemoreceptor sequences distributed across all pseudochromosomes, with a notable underrepresentation in the X chromosome. At least 54% of them localize in 83 genomic clusters with a significantly lower evolutionary distances between them than the average of the family, suggesting a recent origin of many of them. This chromosome-level assembly is the first high-quality genome representative of the Synspermiata clade, and just the third among spiders, representing a new valuable resource to gain insights into the structure and organization of chelicerate genomes, including the role that structural variants, repetitive elements and large gene families played in the extraordinary biology of spiders.

Twenty years, eight legs, one concept: describing spider biodiversity in Zootaxa (Arachnida: Araneae)

Zootaxa published more than a thousand papers on Araneae from 2002 to the present, including descriptions of 3,833 new spider species and 177 new genera. Here we summarise the key contributions of Zootaxa to our current knowledge of global spider diversity. We provide a historical account of the researchers that have actively participated as editors, and recognize the more than 1,000 reviewers without whom none of this would have been possible. We conduct a simple analysis of the contributions by authors and geographic region, which allows us to uncover some of the underlying trends in current spider taxonomy. In addition, we examine some of the milestones in twenty years of spider systematic research in Zootaxa. Finally, we discuss future prospects of spider taxonomy and the role that Zootaxa and its younger sister journal Megataxa will play in it. We would like to dedicate this contribution to the memory of Norman I. Platnick, a crucial figure in the advancement of spider systematics.

A happy family: systematic revision of the endemic Theridion spiders (Araneae, Theridiidae) of the Hawaiian Islands

Since the description in 1900 of the iconic Happy Face spider, Theridion grallator, Simon, along with nine relatives, the Theridion fauna of the Hawaiian Islands has remained unstudied. Here, we present a systematic revision of the Hawaiian Theridion, which includes the examination of abundant material collected during the last 50 years, with scanning of the genitalia of several species using SEM techniques, and a cladistic analysis based on 22 morphological characters, to provide a first hypothesis of the phylogenetic structure of the group. We describe eight new species, namely T. ariel, sp. nov., T. caliban, sp. nov., T. ceres, sp. nov., T. ferdinand, sp. nov., T. juno, sp. nov., T. miranda, sp. nov., T. prospero, sp. nov. and T. sycorax, sp. nov. Additionally, we provide new diagnoses for former species and illustrate and describe for the first time the male of T. kauaiense Simon, 1900 and the female of T. praetextum Simon, 1900. We further propose that T. campestratum Simon, 1900 is a junior synonym of T. melinum Simon, 1900 and T. praetextum concolor Simon, 1900 is a junior synonym of T. praetextum. Finally, we provide updated information on the distribution of the species. Most species are easily diagnosed based on the male and female genitalia, but we also reveal the existence of somatic characters that differ among species, such as the body size and the shape and size of the chelicerae, which may have played a role in the diversification and coexistence of some of the species. The preferred cladogram from the cladistic analysis, although compatible with a progression rule, also suggests a complex pattern of multiple back and forward colonisations, albeit most of the clades are poorly supported.

Integrative taxonomic revision of the woodlouse-hunter spider genus Dysdera (Araneae: Dysderidae) in the Madeira archipelago with notes on its conservation status

Dysdera is a highly speciose genus of mid-sized, nocturnal hunting spiders, mostly circumscribed to the Mediterranean. The genus managed to colonize all Macaronesian archipelagos, and underwent major diversification in the Canary Islands. Here, we report on an independent diversification event on the Madeira archipelago. Based on the integration of morphological and molecular evidence, we describe 8 new species to science, Dysdera dissimilis sp. nov., Dysdera exigua sp. nov., Dysdera isambertoi sp. nov., Dysdera precaria sp. nov., Dysdera recondita sp. nov., Dysdera sandrae sp. nov., Dysdera teixeirai sp. nov., Dysdera titanica sp. nov. and redescribe Dysdera coiffaiti, Dysdera diversa and Dysdera portisancti. We synonymize Dysdera longibulbis and Dysdera vandeli under D. coiffaiti and D. diversa, respectively. Additionally, we use a multilocus target gene phylogeny to support a single colonization event of the archipelago followed by in situ diversification. We further discuss the discovered diversity patterns and their drivers. We conclude to that many of the species inhabit disturbed or fragile habitats and should be considered of high conservation concern.

A new species of Cerroneuroterus Melika Pujade-Villar from the Eastern Palaearctic (Hymenoptera, Cynipidae, Cynipini)

A new gall wasp species, Cerroneuroterus yukawamasudai Pujade-Villar Melika sp. nov., is described from China. The asexual generation induces leaf lenticular galls, and the sexual generation induces catkin galls on Q. acutissima and Q. variabilis. Sexual females and males are not described yet. Data on the diagnosis, distribution, and biology of the new species are provided, including a key to sexual and asexual females of all described Cerroneuroterus species. Previous misidentifications of host galls recorded in Japan are commented on. Molecular analyses were performed to assess the validity of the genus Cerroneuroterus and the affiliation of the new species.

Current status of Andricus mairei (Kieffer), with synonymization of two species from China (Hymenoptera: Cynipidae)

The original description of Parandricus mairei Kieffer, 1906 included a misinterpretation of a relevant forewing trait. The species was subsequently transferred to the genus Andricus, despite presenting two very peculiar morphological characters, namely a simple tarsal claw and the absence of irradiating carinae on the lower face. Similarly, the original descriptions of Andricus deqingis Wang, Gui, Chen, 2013 and A. flavus Pujade-Villar, Wang, Guo Chen, 2014 included some relevant mistakes. Here, we present the results of a molecular analysis that reveals that individuals of the three species are genetically very similar; supporting the proposal that A. mairei is a senior synonym of the other two species, A. deqingis n. syn. and A. flavus n. syn. In addition, our results indicate that Parandricus renders Andricus paraphyletic, which supports that Parandricus is a junior synonym of Andricus. We re-describe and illustrate the relevant characters of A. mairei and provide additional comments on the characters erroneously interpreted in the former descriptions and give notes about the biology and intraspecific variability.

Mitochondrial discordance in closely related Theridion spiders (Araneae, Theridiidae), with description of a new species of the T. melanurum group

The incorporation of molecular data into current taxonomic practise has unravelled instances of incongruence among different data sets. Here we report a case of mitochondrial discordance in cobweb spiders of the genus Theridion Walckenaer, 1805 from the Iberian Peninsula. Morphological examination of samples from a country-wide bioinventory initiative revealed the existence of a putative new species and two nominal species belonging to the Theridion melanurum species group. The morphological delineation was supported by the molecular analysis of a nuclear marker but was at odds with the groups circumscribed by a mitochondrial marker. The causes of this discordance remained uncertain, once sample and sequencing errors and the existence of pseudogenes were discarded. The full sorting observed in the alleles of the more slowly evolving nuclear marker ruled out incomplete lineage sorting, while the geographic patterns recovered were difficult to reconciliate with ongoing hybridization. We propose that the apparent incongruence observed is most likely the result of old introgression events in a group with high dispersal abilities. We further speculate that endosymbiont-driven cytoplasmatic incompatibility could be involved in the fixation of mitochondrial haplotypes across species barriers. Additionally, we describe the new species T. promiscuumsp. nov., based on the presence of diagnostic morphological traits, backed up by the nuclear data delimitation. Our study contributes yet another example of the perils of relying on single methods or data sources to summarise the variation generated by multiple processes acting through thousands of years of evolution and supports the key role of biological inventories in improving our knowledge of invertebrate biodiversity.

A database of functional traits for spiders from native forests of the Iberian Peninsula and Macaronesia

Background

There is an increasing demand for databases including species trait information for biodiversity and community ecology studies. The existence of trait databases is useful for comparative studies within taxa or geographical regions, but there is low availability of databases for certain organisms. Here we present an open access functional trait database for spiders from Macaronesia and the Iberian Peninsula, recording several morphological and ecological traits related to the species life histories, microhabitat and trophic preferences.

New information

We present a database that includes 12 biological traits for 506 spider species present in natural forests of the Iberian Peninsula (Spain) and three Macaronesian archipelagoes (Azores, Madeira and Canary Islands). The functional trait database consists of two sections:

individual-level data for six morphological traits (total body size, prosoma length, prosoma width, prosoma height, tibia I length and fang length), based on direct measurements of 2844 specimens of all spider species; and

species-level aggregate data for 12 traits (same 6 morphological traits as in the previous section plus dispersal ability, vertical stratification, circadian activity, foraging strategy, trophic specialization and colonization status), based on either the average of the direct measurements or bibliographic searches.

This functional trait database will serve as a data standard for currently ongoing analyses that require trait and functional diversity statistics.

Monophyly, Taxon Sampling, and the Nature of Ranks in the Classification of Orb-Weaving Spiders (Araneae: Araneoidea)

We address some of the taxonomic and classification changes proposed by Kuntner et al. (2019) in a comparative study on the evolution of sexual size dimorphism in nephiline spiders. Their proposal to recircumscribe araneids and to rank the subfamily Nephilinae as a family is fundamentally flawed as it renders the family Araneidae paraphyletic. We discuss the importance of monophyly, outgroup selection, and taxon sampling, the subjectivity of ranks, and the implications of the age of origin criterion to assign categorical ranks in biological classifications. We explore the outcome of applying the approach of Kuntner et al. (2019) to the classification of spiders with emphasis on the ecribellate orb-weavers (Araneoidea) using a recently published dated phylogeny. We discuss the implications of including the putative sister group of Nephilinae (the sexually dimorphic genus Paraplectanoides) and the putative sister group of Araneidae (the miniature, monomorphic family Theridiosomatidae). We propose continuation of the phylogenetic classification put forth by Dimitrov et al. (2017), and we formally rank Nephilinae and Phonognathinae as subfamilies of Araneidae. Our classification better reflects the understanding of the phylogenetic placement and evolutionary history of nephilines and phonognathines while maintaining the diagnosability of Nephilinae. It also fulfills the fundamental requirement that taxa must be monophyletic, and thus avoids the paraphyly of Araneidae implied by Kuntner et al. (2019).

A New Genus of Oak Gall Wasp, Striatoandricus Pujade-Villar (Hymenoptera: Cynipidae: Cynipini) from America with Descriptions of Two New Mexican Species

A new genus of cynipid oak gall wasp, Striatoandricus Pujade-Villar (Hymenoptera: Cynipidae: Cynipini), is described. Striatoandricus gen. nov. includes four previously described species, Andricus nievesaldreyi n. comb., A. georgei n. comb., A. maesi n. comb., and A. barriosi n. comb., which induce pubescent leaves or twig galls on Quercus belonging to Quercus section. Two new species from México are also described: S. cuixarti Pujade-Villar n. sp. and S. sanchezi Pujade-Villar n. sp. in Quercus section. Descriptions of the genus and diagnostic characters, including DNA sequence data, are presented. This new genus is supported by both morphological and molecular data.

Arm-less mitochondrial tRNAs conserved for over 30 millions of years in spiders

BACKGROUND

In recent years, Next Generation Sequencing (NGS) has accelerated the generation of full mitogenomes, providing abundant material for studying different aspects of molecular evolution. Some mitogenomes have been observed to harbor atypical sequences with bizarre secondary structures, which origins and significance could only be fully understood in an evolutionary framework.

RESULTS

Here we report and analyze the mitochondrial sequences and gene arrangements of six closely related spiders in the sister genera Parachtes and Harpactocrates, which belong to the nocturnal, ground dwelling family Dysderidae. Species of both genera have compacted mitogenomes with many overlapping genes and strikingly reduced tRNAs that are among the shortest described within metazoans. Thanks to the conservation of the gene order and the nucleotide identity across close relatives, we were able to predict the secondary structures even on arm-less tRNAs, which would be otherwise unattainable for a single species. They exhibit aberrant secondary structures with the lack of either DHU or TΨC arms and many miss-pairings in the acceptor arm but this degeneracy trend goes even further since at least four tRNAs are arm-less in the six spider species studied.

CONCLUSIONS

The conservation of at least four arm-less tRNA genes in two sister spider genera for about 30 myr suggest that these genes are still encoding fully functional tRNAs though they may be post-transcriptionally edited to be fully functional as previously described in other species. We suggest that the presence of overlapping and truncated tRNA genes may be related and explains why spider mitogenomes are smaller than those of other invertebrates.

The draft genome sequence of the spider Dysdera silvatica (Araneae, Dysderidae): A valuable resource for functional and evolutionary genomic studies in chelicerates

BACKGROUND

We present the draft genome sequence of Dysdera silvatica, a nocturnal ground-dwelling spider from a genus that has undergone a remarkable adaptive radiation in the Canary Islands.

RESULTS

The draft assembly was obtained using short (Illumina) and long (PaciBio and Nanopore) sequencing reads. Our de novo assembly (1.36 Gb), which represents 80% of the genome size estimated by flow cytometry (1.7 Gb), is constituted by a high fraction of interspersed repetitive elements (53.8%). The assembly completeness, using BUSCO and core eukaryotic genes, ranges from 90% to 96%. Functional annotations based on both ab initio and evidence-based information (including D. silvatica RNA sequencing) yielded a total of 48,619 protein-coding sequences, of which 36,398 (74.9%) have the molecular hallmark of known protein domains, or sequence similarity with Swiss-Prot sequences. The D. silvatica assembly is the first representative of the superfamily Dysderoidea, and just the second available genome of Synspermiata, one of the major evolutionary lineages of the "true spiders" (Araneomorphae).

CONCLUSIONS

Dysderoids, which are known for their numerous instances of adaptation to underground environments, include some of the few examples of trophic specialization within spiders and are excellent models for the study of cryptic female choice. This resource will be therefore useful as a starting point to study fundamental evolutionary and functional questions, including the molecular bases of the adaptation to extreme environments and ecological shifts, as well of the origin and evolution of relevant spider traits, such as the venom and silk.

Assessment of radon risk areas in the Eastern Canary Islands using soil radon gas concentration and gas permeability of soils

The Basic Safety Standard (BSS) Directive 2013/59/EURATOM of the European Union (EU) has stated the need for member states to establish national action plans to mitigate their general population's long-term risks of exposure to radon gas. Maps of radon-prone areas provide a useful tool for the development of such plans. This paper presents the maps of radon-prone areas in the Eastern Canary Islands (Gran Canaria, Fuerteventura and Lanzarote) obtained from assessment of Geogenic Radon Potential (GRP) distribution in the territory. GRP constitutes a magnitude that is contingent on both radon activity concentration and gas permeability of soils. An extensive campaign covering all geological formations of the Eastern Canary Islands was undertaken to locally sample these parameters. Geostatistical analysis of the spatial distribution of radon concentration in soils, permeability and GRP was performed on each of the islands, and the relationship between these magnitudes and the characteristic geological formations of the volcanic islands was investigated. Areas dominated by basic volcanic and plutonic rocks (originated by both recent and ancient volcanism) exhibit relatively low levels of radon in soils, and with the exception of specific cases of very high permeability, these areas are not classified as prone to radon risk according to international criteria. Areas in which intermediate or acidic volcanic and plutonic rocks predominate are characterised by greater radon activity concentration in soils, rendering them radon-prone. Given these results, Lanzarote is classified as an island with low radon risk all over its surface; Fuerteventura presents low-medium risk; and Gran Canaria contains extensive areas in the centre and north where the risk is medium or high. This classification is consistent with the risk maps obtained by National and European agencies from indoor radon measurements conducted on these islands.

Natural radioactivity in algae arrivals on the Canary coast and dosimetry assessment

Nowadays, the use of wild and culture harvest seaweed in food industry is a booming productive sector. In this context, a radiological characterization of five globally common seaweed species that were collected in arrival on Gran Canaria coast was carried out. The studied algae species were Cymopolia barbata, Lobophora variegata, Sargassum vulgare, Dictyota dichotoma and Haliptilon virgatum. Radionuclides analysed by alpha and gamma spectrometry were ²³⁸U, ²³⁴U, ²³⁵U, ²¹⁰Po, ²³⁴Th, ²²⁶Ra, ²¹⁰Pb, ²²⁸Th, ²²⁴Ra, ⁴⁰K and ⁷Be. Activity concentrations, ratios, and concentration factors (CF) were determined for all samples collected. The CF in algae was higher for reactive-particle radionuclides (²¹⁰Po, ²³⁴Th, ²²⁸Th and ²¹⁰Pb) than for conservative ones (⁴⁰K and the uranium isotopes). ²¹⁰Po, ²²⁸Th and ²³⁴Th CF were one or two orders of magnitude higher than those recommended by the IAEA. L. variegata, C. barbata and S. vulgare showed a clear preference for ²¹⁰Pb and ²¹⁰Po, for uranium radioisotopes, and for ⁴⁰K and ²³⁴Th, respectively. A dosimetry assessment due to seaweed ingestion showed considerable values of annual committed effective dose for H. virgatum (605 ± 19 μSv/y), L. variegata (574 ± 17 μSv/y) and D. dichotoma (540 ± 30 μSv/y). Hence, this study suggests that an algae radiological characterization is recommended as part of the product valorising process.

The Grass was Greener: Repeated Evolution of Specialized Morphologies and Habitat Shifts in Ghost Spiders Following Grassland Expansion in South America

While grasslands, one of Earth's major biomes, are known for their close evolutionary ties with ungulate grazers, these habitats are also paramount to the origins and diversification of other animals. Within the primarily South American spider subfamily Amaurobioidinae (Anyphaenidae), several species are found living in the continent's grasslands, with some displaying putative morphological adaptations to dwelling unnoticed in the grass blades. Herein, a dated molecular phylogeny provides the backbone for analyses revealing the ecological and morphological processes behind these spiders' grassland adaptations. The multiple switches from Patagonian forests to open habitats coincide with the expansion of South America's grasslands during the Miocene, while the specialized morphology of several grass-dwelling spiders originated at least three independent times and is best described as the result of different selective regimes operating on macroevolutionary timescales. Although grass-adapted lineages evolved towards different peaks in adaptive landscape, they all share one characteristic: an anterior narrowing of the prosoma allowing spiders to extend the first two pairs of legs, thus maintaining a slender resting posture in the grass blade. By combining phylogenetic, morphological, and biogeographic perspectives we disentangle multiple factors determining the evolution of a clade of terrestrial invertebrate predators alongside their biomes.

A DNA barcode-assisted annotated checklist of the spider (Arachnida, Araneae) communities associated to white oak woodlands in Spanish National Parks

BACKGROUND

A large scale semi-quantitative biodiversity assessment was conducted in white oak woodlands in areas included in the Spanish Network of National Parks, as part of a project aimed at revealing biogeographic patterns and identify biodiversity drivers. The semi-quantitative COBRA sampling protocol was conducted in sixteen 1-ha plots across six national parks using a nested design. All adult specimens were identified to species level based on morphology. Uncertain delimitations and identifications due to either limited information of diagnostic characters or conflicting taxonomy were further investigated using DNA barcode information.

NEW INFORMATION

We identified 376 species belonging to 190 genera in 39 families, from the 8,521 adults found amongst the 20,539 collected specimens. Faunistic results include the discovery of 7 new species to the Iberian Peninsula, 3 new species to Spain and 11 putative new species to science. As largely expected by environmental features, the southern parks showed a higher proportion of Iberian and Mediterranean species than the northern parks, where the Palearctic elements were largely dominant. The analysis of approximately 3,200 DNA barcodes generated in the present study, corroborated and provided finer resolution to the morphologically based delimitation and identification of specimens in some taxonomically challenging families. Specifically, molecular data confirmed putative new species with diagnosable morphology, identified overlooked lineages that may constitute new species, confirmed assignment of specimens of unknown sexes to species and identified cases of misidentifications and phenotypic polymorphisms.

Phylogenomics, Diversification Dynamics, and Comparative Transcriptomics across the Spider Tree of Life

Dating back to almost 400 mya, spiders are among the most diverse terrestrial predators [1]. However, despite considerable effort [1-9], their phylogenetic relationships and diversification dynamics remain poorly understood. Here, we use a synergistic approach to study spider evolution through phylogenomics, comparative transcriptomics, and lineage diversification analyses. Our analyses, based on ca. 2,500 genes from 159 spider species, reject a single origin of the orb web (the "ancient orb-web hypothesis") and suggest that orb webs evolved multiple times since the late Triassic-Jurassic. We find no significant association between the loss of foraging webs and increases in diversification rates, suggesting that other factors (e.g., habitat heterogeneity or biotic interactions) potentially played a key role in spider diversification. Finally, we report notable genomic differences in the main spider lineages: while araneoids (ecribellate orb-weavers and their allies) reveal an enrichment in genes related to behavior and sensory reception, the retrolateral tibial apophysis (RTA) clade-the most diverse araneomorph spider lineage-shows enrichment in genes related to immune responses and polyphenic determination. This study, one of the largest invertebrate phylogenomic analyses to date, highlights the usefulness of transcriptomic data not only to build a robust backbone for the Spider Tree of Life, but also to address the genetic basis of diversification in the spider evolutionary chronicle.

Taxonomic revision and insights into the speciation mode of the spider Dysdera erythrina species-complex (Araneae : Dysderidae): sibling species with sympatric distributions

The genus Dysdera Latreille, 1804, a species-rich group of spiders that includes specialised predators of woodlice, contains several complexes of morphologically similar sibling species. Here we investigate species limits in the D. erythrina (Walckenaer, 1802) complex by integrating phenotypic, cytogenetic and molecular data, and use this information to gain further knowledge on its origin and evolution. We describe 16 new species and redescribe four poorly known species belonging to this clade. The distribution of most of the species in the complex is limited to southern France and the north-eastern Iberian Peninsula. The species studied do not show any obvious differences in habitat preference, and some of them even occur sympatrically at certain sites. They probably feed on the same type of prey as they readily capture woodlice. On the other hand, they differ in body size, mouthparts shape, sculpturing of carapace, morphology of the copulatory organs, karyotype and DNA sequences. Experimental interspecific mating showed a partial precopulatory behavioural barrier between D. erythrina and D. cechica, sp. nov. Our data suggest that karyotype evolution of the complex included chromosome fusions and fissions as well as translocations (between autosomes as well as autosomes and sex chromosomes). We hypothesise that chromosome rearrangements generating reproductive incompatibility played a primary role in speciation within Dysdera complexes. Dysdera spiders are poor dispersers, and their original distribution areas (forested areas in the Mediterranean) were repeatedly fragmented during Quarternary climatic oscillations, facilitating integration of chromosome rearrangements into karyotypes by genetic drift. Sympatric occurrence of closely related species may have been promoted by prey segregation as suggested by differentiation in body size in co-occurring species. The following new species are described: D. catalonica, sp. nov., D. cechica, D. dolanskyi, sp. nov., D. fabrorum, sp. nov., D. garrafensis, sp. nov., D. graia, sp. nov., D. kropfi, sp. nov., D. minairo, sp. nov., D. portsensis, sp. nov., D. pradesensis, sp. nov., D. pyrenaica, sp. nov., D. quindecima, sp. nov., D. septima, sp. nov., D. stahlavskyi, sp. nov., D. tredecima, sp. nov. and D. undecima, sp. nov.

Ecological speciation in darkness? Spatial niche partitioning in sibling subterranean spiders (Araneae : Linyphiidae : Troglohyphantes)

Speciation in subterranean habitats is commonly explained as the result of divergent selection in geographically isolated populations; conversely, the contribution of niche partitioning in driving subterranean species diversification has been rarely quantified. The present study integrated molecular and morphological data with a hypervolume analysis based on functional traits to investigate a potential case of parapatric speciation by means of niche differentiation in two sibling spiders inhabiting contiguous subterranean habitats within a small alpine hypogean site. Troglohyphantes giachinoi, sp. nov. and T. bornensis are diagnosed by small details of the genitalia, which are likely to be involved in a reproductive barrier. Molecular analysis recovered the two species as sister, and revealed a deep genetic divergence that may trace back to the Messinian (~6 million years ago). The hypervolume analysis highlighted a marginal overlap in their ecological niches, coupled with morphological character displacement. Specifically, T. giachinoi, sp. nov. exhibits morphological traits suitable for thriving in the smaller pores of the superficial network of underground fissures (Milieu Souterrain Superficiel, MSS), whereas T. bornensis shows a greater adaptation to the deep subterranean habitat. Our results suggest that different selective regimes within the subterranean environment, i.e. deep caves v. MSS, may either drive local speciation or facilitate contiguous distributions of independently subterranean adapted species.

Evolution of Chemosensory Gene Families in Arthropods: Insight from the First Inclusive Comparative Transcriptome Analysis across Spider Appendages

Unlike hexapods and vertebrates, in chelicerates, knowledge of the specific molecules involved in chemoreception comes exclusively from the comparative analysis of genome sequences. Indeed, the genomes of mites, ticks and spiders contain several genes encoding homologs of some insect membrane receptors and small soluble chemosensory proteins. Here, we conducted for the first time a comprehensive comparative RNA-Seq analysis across different body structures of a chelicerate: the nocturnal wandering hunter spider Dysdera silvatica Schmidt 1981. Specifically, we obtained the complete transcriptome of this species as well as the specific expression profile in the first pair of legs and the palps, which are thought to be the specific olfactory appendages in spiders, and in the remaining legs, which also have hairs that have been morphologically identified as chemosensory. We identified several ionotropic (Ir) and gustatory (Gr) receptor family members exclusively or differentially expressed across transcriptomes, some exhibiting a distinctive pattern in the putative olfactory appendages. Furthermore, these IRs were the only known olfactory receptors identified in such structures. These results, integrated with an extensive phylogenetic analysis across arthropods, uncover a specialization of the chemosensory gene repertoire across the body of D. silvatica and suggest that some IRs likely mediate olfactory signaling in chelicerates. Noticeably, we detected the expression of a gene family distantly related to insect odorant-binding proteins (OBPs), suggesting that this gene family is more ancient than previously believed, as well as the expression of an uncharacterized gene family encoding small globular secreted proteins, which appears to be a good chemosensory gene family candidate.

Updated catalogue and taxonomic notes on the Old-World scorpion genus Buthus Leach, 1815 (Scorpiones, Buthidae)

Since the publication of the ground-breaking "Catalogue of the scorpions of the world (1758-1998)" (Fet et al. 2000) the number of species in the scorpion genus Buthus Leach, 1815 has increased 10-fold, and this genus is now the fourth largest within the Buthidae, with 52 valid named species. Here we revise and update the available information regarding Buthus. A new combination is proposed: Buthus halius (C. L. Koch, 1839), comb. n. from Portugal and Spain. B. halius is removed from junior synonymy with Buthus occitanus (Amoreux, 1789), and proposed as a senior synonym of B. ibericus Lourenço & Vachon, 2004, syn. n. Moreover, following I.C.Z.N. article 23.9.2 we propose to maintain as valid B. ibericus(nomen protectum) and to consider the disued B. halius as a nomen oblitum . Buthus europaeus tridentatus Franganillo, 1918 is proposed as a junior synonym of B. occitanus (Amoreux, 1789), syn. n.Buthus sabulicola Touloun, 2012 is proposed as a junior synonym of Buthus bonito Lourenço & Geniez, 2005, syn. n.Buthus occitanus tunetanus neeli Gysin, 1969 is proposed as an informal senior synonym of Buthus tassili Lourenço, 2002, informal syn. n. Two taxa are rised to species rank, Buthus nigrovesiculosus Hirst, 1925, stat. n. and Buthus parroti Vachon, 1949, stat. n.. We further confirm the restricted distribution of B. occitanus that is confined to southeastern France and northwestern Iberian Peninsula and does not occur in North Africa. Additionally, Androctonus barbouri (Werner, 1932), comb. n. from the Agadir region of Morocco, is hereby transferred to the genus Androctonus. We summarize and provide a critical appraisal of the diagnostic characters currently in use for the genus. The catalogue section considers the names for species, subspecies and varieties that have been used for Buthus scorpions. Information about types, including collection numbers and localities are included when available. Finally, an annotated listing of synonymies and an updated bibliography are given.

Exploring the role of within-island ecogeographical factors: insights from the genetic diversity of Cretan trap-door spiders (Cyrtocarenum cunicularium, Ctenizidae : Araneae)

Crete (Aegean Sea, Greece), like other Mediterranean islands, has a complex palaeogeographical history, including several cycles of fragmentation into palaeoislands and subsequent reconnection. Here, we use the Cretan trap-door spider Cyrtocarenum cunicularium as a model organism to explore the importance of within-island evolutionary processes, such as palaeogeographic events and climatic changes. We assessed the phylogeny, population clustering and historical demography of 61 specimens with mitochondrial (COI) and nuclear (H3) markers. We investigated the isolation-by-distance and spatial diffusion processes that have shaped their past and current distribution and estimated the effect of niche divergence, using species distribution modelling. Two genetic lineages have continuously been distributed in the west and east part of Crete during the last 2million years. Their genetic structure is concordant with Crete’s fragmentation into palaeoislands during the Pliocene and additionally affected by the sea-level oscillations and climatic changes due to the Pleistocenic glacial cycles. In central Crete, some evidence of genetic admixture between them was found, which needs to be further explored. According to species distribution modelling, the niche of each lineage corresponds to different environmental parameters, while isolation-by-distance was also detected. The divergence between the ‘West’ and ‘East’ lineages was promoted by palaeogeographical factors but seems to be maintained by the species’ poor dispersal abilities and the local ecological adaptation of each lineage. The case of the Cretan C. cunicularium highlights the additive effect of ecogeographical and behavioural factors in shaping insular biodiversity.

Mapping natural radioactivity of soils in the eastern Canary Islands

The Canary Islands archipielago (Spain) comprises seven main volcanic islands and several islets that form a chain extending for around 500 km across the eastern Atlantic, between latitudes 27°N and 30°N, with its eastern edge only 100 km from the NW African coast. The administrative province of Las Palmas comprises the three eastern Canary Islands (Lanzarote, Fuerteventura and Gran Canaria). An extensive study of terrestrial gamma dose rates in surface soils has been carried out to cover the entire territory of the province (4093 km²). The average outdoor gamma dose rate in air at 1 m above ground is 73 nGyh^-1 at Gran Canaria, 32 nGyh^-1 at Fuerteventura, and 25 nGyh^-1 at Lanzarote. To complete the radiological characterization of this volcanic area, 350 soil samples at 0-5 cm depth were collected to cover all the geologic typologies of the islands. These samples were measured using high resolution gamma spectrometry to determine the activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K. The average values obtained were 25.2 Bq/kg, 28.9 Bq/kg, and 384.4 Bq/kg, respectively. Maps of terrestrial gamma activity, effective dose, and activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K for the region have been developed through the use of geostatistical interpolation techniques. These maps are in accord with the geology of the islands.

A geographical distribution database of the genus Dysdera in the Canary Islands (Araneae, Dysderidae)

The ground-dweller spider genus Dysdera shows very high species richness on the oceanic archipelago of the Canary Islands, providing one of the most outstanding examples of island radiation among spiders, only paralleled by Tetragnatha spiders on the Hawaiian archipelago. A georeferenced database of the 48 Dysdera species occurring in the Canary Islands was assembled to facilitate ongoing and future research on this remarkable lineage. All species are endemic to the archipelago except for the cosmopolitan Dysdera crocata. The dataset consists of 794 distributional records documented from 1971 to 2015, each locality being represented only once per species. Distribution maps are provided for each species, along with basic diversity and distribution information. The database and geographical maps included in this article stand for the most updated, accurate and complete information on the distribution of the spider genus Dysdera in the Canary Islands.

Alpine endemic spiders shed light on the origin and evolution of subterranean species

We designed a comparative study to unravel the phylogeography of two Alpine endemic spiders characterized by a different degree of adaptation to subterranean life: Troglohyphantes vignai (Araneae, Linyphiidae) and Pimoa rupicola (Araneae, Pimoidae), the latter showing minor adaptation to hypogean life. We sampled populations of the model species in caves and other subterranean habitats across their known geographical range in the Western Alps. By combining phylogeographic inferences and Ecological Niche Modeling techniques, we inferred the biogeographic scenario that led to the present day population structure of the two species. According to our divergent time estimates and relative uncertainties, the isolation of T. vignai and P. rupicola from their northern sister groups was tracked back to Middle–Late Miocene. Furthermore, the fingerprint left by Pleistocene glaciations on the population structure revealed by the genetic data, led to the hypothesis that a progressive adaptation to subterranean habitats occurred in T. vignai, followed by strong population isolation. On the other hand, P. rupicola underwent a remarkable genetic bottleneck during the Pleistocene glaciations, that shaped its present population structure. It seems likely that such shallow population structure is both the result of the minor degree of specialization to hypogean life and the higher dispersal ability characterizing this species. The simultaneous study of overlapping spider species showing different levels of adaptation to hypogean life, disclosed a new way to clarify patterns of biological diversification and to understand the effects of past climatic shift on the subterranean biodiversity.

Unexpected diversity in the relictual European spiders of the genus Pimoa (Araneae : Pimoidae)

Pimoidae is a small family of araneoid spiders, hitherto represented in Europe by two species with disjunct distribution in the Alps and in the Cantabrian Mountains of northern Spain. Here we report the description of two additional European species of Pimoa, discovered within the range of the only former alpine species, P. rupicola: P. graphitica sp. nov. and P. delphinica sp. nov. The new species are distinguished from the latter by genitalic characters as well as by molecular characters. On the basis of the re-examination of old and recent abundant material collected in caves and other subterranean habitats, we revise the distribution patterns of the genus Pimoa in the Alps and outline the species distribution ranges. Molecular data suggest the existence of gene flow between populations of the two new species when in sympatry. The different species probably originated in the alpine region as a result of range contractions following dramatic climatic changes in the Alps since the mid Miocene. We interpreted the present-day overlapping distribution in light of a possible postglacial expansion. Finally, we provide insights on the natural history and life cycles of the new species and discuss their phylogenetic relationships within Pimoidae.

Bone-Eating Worms Spread: Insights into Shallow-Water Osedax (Annelida, Siboglinidae) from Antarctic, Subantarctic, and Mediterranean Waters

Osedax, commonly known as bone-eating worms, are unusual marine annelids belonging to Siboglinidae and represent a remarkable example of evolutionary adaptation to a specialized habitat, namely sunken vertebrate bones. Usually, females of these animals live anchored inside bone owing to a ramified root system from an ovisac, and obtain nutrition via symbiosis with Oceanospirillales gamma-proteobacteria. Since their discovery, 26 Osedax operational taxonomic units (OTUs) have been reported from a wide bathymetric range in the Pacific, the North Atlantic, and the Southern Ocean. Using experimentally deployed and naturally occurring bones we report here the presence of Osedax deceptionensis at very shallow-waters in Deception Island (type locality; Antarctica) and at moderate depths near South Georgia Island (Subantarctic). We present molecular evidence in a new phylogenetic analysis based on five concatenated genes (28S rDNA, Histone H3, 18S rDNA, 16S rDNA, and cytochrome c oxidase I-COI-), using Maximum Likelihood and Bayesian inference, supporting the placement of O. deceptionensis as a separate lineage (Clade VI) although its position still remains uncertain. This phylogenetic analysis includes a new unnamed species (O. 'mediterranea') recently discovered in the shallow-water Mediterranean Sea belonging to Osedax Clade I. A timeframe of the diversification of Osedax inferred using a Bayesian framework further suggests that Osedax diverged from other siboglinids during the Middle Cretaceous (ca. 108 Ma) and also indicates that the most recent common ancestor of Osedax extant lineages dates to the Late Cretaceous (ca. 74.8 Ma) concomitantly with large marine reptiles and teleost fishes. We also provide a phylogenetic framework that assigns newly-sequenced Osedax endosymbionts of O. deceptionensis and O. 'mediterranea' to ribospecies Rs1. Molecular analysis for O. deceptionensis also includes a COI-based haplotype network indicating that individuals from Deception Island and the South Georgia Island (ca. 1,600 km apart) are clearly the same species, confirming the well-developed dispersal capabilities reported in other congeneric taxa. In addition, we include a complete description of living features and morphological characters (including scanning and transmission electron microscopy) of O. deceptionensis, a species originally described from a single mature female, and compare it to information available for other congeneric OTUs.

A simple methodology for characterization of germanium coaxial detectors by using Monte Carlo simulation and evolutionary algorithms

The determination in a sample of the activity concentration of a specific radionuclide by gamma spectrometry needs to know the full energy peak efficiency (FEPE) for the energy of interest. The difficulties related to the experimental calibration make it advisable to have alternative methods for FEPE determination, such as the simulation of the transport of photons in the crystal by the Monte Carlo method, which requires an accurate knowledge of the characteristics and geometry of the detector. The characterization process is mainly carried out by Canberra Industries Inc. using proprietary techniques and methodologies developed by that company. It is a costly procedure (due to shipping and to the cost of the process itself) and for some research laboratories an alternative in situ procedure can be very useful. The main goal of this paper is to find an alternative to this costly characterization process, by establishing a method for optimizing the parameters of characterizing the detector, through a computational procedure which could be reproduced at a standard research lab. This method consists in the determination of the detector geometric parameters by using Monte Carlo simulation in parallel with an optimization process, based on evolutionary algorithms, starting from a set of reference FEPEs determined experimentally or computationally. The proposed method has proven to be effective and simple to implement. It provides a set of characterization parameters which it has been successfully validated for different source-detector geometries, and also for a wide range of environmental samples and certified materials.

Comparative analysis of tissue-specific transcriptomes in the funnel-web spider Macrothele calpeiana (Araneae, Hexathelidae)

The funnel-web spider Macrothele calpeiana is a charismatic Mygalomorph with a great interest in basic, applied and translational research. Nevertheless, current scarcity of genomic and transcriptomic data of this species clearly limits the research in this non-model organism. To overcome this limitation, we launched the first tissue-specific enriched RNA-seq analysis in this species using a subtractive hybridization approach, with two main objectives, to characterize the specific transcriptome of the putative chemosensory appendages (palps and first pair of legs), and to provide a new set of DNA markers for further phylogenetic studies. We have characterized the set of transcripts specifically expressed in putative chemosensory tissues of this species, much of them showing features shared by chemosensory system genes. Among specific candidates, we have identified some members of the iGluR and NPC2 families. Moreover, we have demonstrated the utility of these newly generated data as molecular markers by inferring the phylogenetic position M. calpeina in the phylogenetic tree of Mygalomorphs. Our results provide novel resources for researchers interested in spider molecular biology and systematics, which can help to expand our knowledge on the evolutionary processes underlying fundamental biological questions, as species invasion or biodiversity origin and maintenance.

Extant primitively segmented spiders have recently diversified from an ancient lineage

Living fossils are lineages that have retained plesiomorphic traits through long time periods. It is expected that such lineages have both originated and diversified long ago. Such expectations have recently been challenged in some textbook examples of living fossils, notably in extant cycads and coelacanths. Using a phylogenetic approach, we tested the patterns of the origin and diversification of liphistiid spiders, a clade of spiders considered to be living fossils due to their retention of arachnid plesiomorphies and their exclusive grouping in Mesothelae, an ancient clade sister to all modern spiders. Facilitated by original sampling throughout their Asian range, we here provide the phylogenetic framework necessary for reconstructing liphistiid biogeographic history. All phylogenetic analyses support the monophyly of Liphistiidae and of eight genera. As the fossil evidence supports a Carboniferous Euramerican origin of Mesothelae, our dating analyses postulate a long eastward over-land dispersal towards the Asian origin of Liphistiidae during the Palaeogene (39-58 Ma). Contrary to expectations, diversification within extant liphistiid genera is relatively recent, in the Neogene and Late Palaeogene (4-24 Ma). While no over-water dispersal events are needed to explain their evolutionary history, the history of liphistiid spiders has the potential to play prominently in vicariant biogeographic studies.