Biomechanics: Rain yields tougher spider silks.

Broad ecological sampling of spider silks from multiple species shows that the biomechanical properties of spider silk reflect the habitat in which their orb webs are built. Silk toughness is highest in habitats with dense rain.

Eyeless cave-dwelling spiders still rely on light.

Subterranean animals living in perpetual darkness may maintain photoresponse. However, the evolutionary processes behind the conflict between eye loss and maintenance of the photoresponse remain largely unknown. We used spiders to investigate the driving forces behind the maintenance of the photoresponse in cave-dwelling spiders.

Increasing Information Content and Diagnosability in Family-Level Classifications.

Higher-level classifications often must account for monotypic taxa representing depauperate evolutionary lineages and lacking synapomorphies of their better-known, well-defined sister clades. In a ranked (Linnean) or unranked (phylogenetic) classification system, discovering such a depauperate taxon does not necessarily invalidate the rank classification of sister clades. Named higher taxa must be monophyletic to be phylogenetically valid.

Description and phylogenetic analysis of two new (Araneae, Theridiidae) species from China.

The spider genus Walckenaer, 1809 currently contains 66 species worldwide, mostly in warm temperate to tropical areas. This paper describes two new Chinese species: (♂♀) and (♀). We add these two new and one known species to the phylogenetic data matrix of Liu et al.

Biogeography and eye size evolution of the ogre-faced spiders.

Net-casting spiders (Deinopidae) comprise a charismatic family with an enigmatic evolutionary history. There are 67 described species of deinopids, placed among three genera, Deinopis, Menneus, and Asianopis, that are distributed globally throughout the tropics and subtropics. Deinopis and Asianopis, the ogre-faced spiders, are best known for their giant light-capturing posterior median eyes (PME), whereas Menneus does not have enlarged PMEs.

Safety is increasingly important in cobweb spiders based on life history.

Detritus-based, bell-shaped cobwebs are an ideal model to research the plasticity of web architecture due to clearly separate defense and foraging components. We performed a thorough field investigation on the web architectures of Campanicola campanulata to research its cobweb architecture variation during the growth process and analyzed the energy trade-offs between foraging and defense at different developmental stages. The results indicated that as female C.

Characterization of the genome and silk-gland transcriptomes of Darwin's bark spider (Caerostris darwini).

Natural silks crafted by spiders comprise some of the most versatile materials known. Artificial silks-based on the sequences of their natural brethren-replicate some desirable biophysical properties and are increasingly utilized in commercial and medical applications today. To characterize the repertoire of protein sequences giving silks their biophysical properties and to determine the set of expressed genes across each unique silk gland contributing to the formation of natural silks, we report here draft genomic and transcriptomic assemblies of Darwin's bark spider, Caerostris darwini, an orb-weaving spider whose dragline is one of the toughest known biomaterials on Earth.

 species (Araneae, Theridiidae) from China.

In an ongoing effort to expand knowledge of the Chinese cobweb spider fauna (Theridiidae), the genus Simon, 1894 is reviewed. Two new species are described, , , and five known species are redescribed: (Yaginuma, 1952), (Mello-Leitão, 1917), Simon, 1895, (O. Pickard-Cambridge, 1869), and Simon, 1895.

A molecular phylogeny of the Chinese spiders (Sparassidae, Heteropodinae): implications for taxonomy.

spiders are a diverse group with limited dispersal ability. They are remarkably sympatric among related species, which often results in misidentification and incorrect matching of sexes. In order to understand the evolutionary relationships and revise the taxonomy problems in this genus, we offer the first molecular phylogeny of .

Eight cobweb spider species from China building detritus-based, bell-shaped retreats (Araneae, Theridiidae).

Eight cobweb spider species building a detritus-based, bell-shaped retreat from China are reported in the current paper, including five new species and three known species: Li & Liu, , Li & Liu, , Li & Liu, , Li & Liu, , Li & Liu, , (Chen, 1993), (Bösenberg & Strand, 1906), and (Zhu, 1998). Among them, the male of (Zhu, 1998) is described for the first time. We provide photographs of all species and descriptions for new species in the current paper.

Correlation between protein secondary structure and mechanical performance for the ultra-tough dragline silk of Darwin's bark spider.

The spider major ampullate (MA) silk exhibits high tensile strength and extensibility and is typically a blend of MaSp1 and MaSp2 proteins with the latter comprising glycine-proline-glycine-glycine-X repeating motifs that promote extensibility and supercontraction. The MA silk from Darwin's bark spider () is estimated to be two to three times tougher than the MA silk from other spider species. Previous research suggests that a unique MaSp4 protein incorporates proline into a novel glycine-proline-glycine-proline motif and may explain MA silk's extraordinary toughness.

(Araneae, Oonopidae) spiders from Hispaniola: the discovery of ten new species.

The Caribbean biodiversity hotspot harbors vast reserves of undiscovered species. A large-scale inventory of Caribbean arachnids (CarBio) is uncovering new species across the arachnid tree of life, and allowing inference of the evolutionary history that has generated this diversity. Herein we describe ten new species of (Oonopidae, or goblin spiders), from Hispaniola: , , , , , , , , and The occurrence of the pantropical type species (Simon, 1891) is reported and new localities are given for: (Bryant, 1948), (Platnick & Dupérré, 2009) and (Platnick & Dupérré, 2009).

Phylogeography of the widespread Caribbean spiny orb weaver .

Background: Modern molecular analyses are often inconsistent with pre-cladistic taxonomic hypotheses, frequently indicating higher richness than morphological taxonomy estimates. Among Caribbean spiders, widespread species are relatively few compared to the prevalence of single island endemics. The taxonomic hypothesis circumscribes a species with profuse variation in size, color and body form.

Global Diversification of Anelosimus Spiders Driven by Long-Distance Overwater Dispersal and Neogene Climate Oscillations.

Vicariance and dispersal events, combined with intricate global climatic history, have left an imprint on the spatiotemporal distribution and diversity of many organisms. Anelosimus cobweb spiders (Theridiidae), are organisms ranging in behavior from solitary to highly social, with a cosmopolitan distribution in temperate to tropical areas. Their evolutionary history and the discontinuous distribution of species richness suggest that 1) long-distance overwater dispersal and 2) climate change during the Neogene (23-2.

New species of smiley-faced spider (Araneae, Theridiidae) from Brazil, and comments on unobserved diversity in South America.

is a genus of spiders that contained only two species until 2018 when it was demonstrated that a 'widespread' species was instead composed of multiple short-range endemics. This note redescribes Keyserling and describes a new species of (Araneae, Theridiidae), , both based on specimens from Brazil. We also examine specimens from several additional localities in Brazil displaying variation consistent with patterns previously found within the Caribbean: geographically isolated and unique localities may contain independent species lineages.

Phylogeny of the orb-weaving spider family Araneidae (Araneae: Araneoidea).

We present a new phylogeny of the spider family Araneidae based on five genes (28S, 18S, COI, H3 and 16S) for 158 taxa, identified and mainly sequenced by us. This includes 25 outgroups and 133 araneid ingroups representing the subfamilies Zygiellinae Simon, 1929, Nephilinae Simon, 1894, and the typical araneids, here informally named the "ARA Clade". The araneid genera analysed here include roughly 90% of all currently named araneid species.

The transcriptome of Darwin's bark spider silk glands predicts proteins contributing to dragline silk toughness.

Darwin's bark spider () produces giant orb webs from dragline silk that can be twice as tough as other silks, making it the toughest biological material. This extreme toughness comes from increased extensibility relative to other draglines. We show dragline-producing major ampullate (MA) glands highly express a novel silk gene transcript (MaSp4) encoding a protein that diverges markedly from closely related proteins and contains abundant proline, known to confer silk extensibility, in a unique GPGPQ amino acid motif.

Spiders did not repeatedly gain, but repeatedly lost, foraging webs.

Much genomic-scale, especially transcriptomic, data on spider phylogeny has accumulated in the last few years. These data have recently been used to investigate the diverse architectures and the origin of spider webs, concluding that the ancestral spider spun no foraging web, that spider webs evolved 10-14 times, and that the orb web evolved at least three times. These findings in fact result from a particular phylogenetic character coding strategy, specifically coding the of webs as logically equivalent, and homologous to, 10 other observable (i.

Biogeography of the Caribbean Cyrtognatha spiders.

Island systems provide excellent arenas to test evolutionary hypotheses pertaining to gene flow and diversification of dispersal-limited organisms. Here we focus on an orbweaver spider genus Cyrtognatha (Tetragnathidae) from the Caribbean, with the aims to reconstruct its evolutionary history, examine its biogeographic history in the archipelago, and to estimate the timing and route of Caribbean colonization. Specifically, we test if Cyrtognatha biogeographic history is consistent with an ancient vicariant scenario (the GAARlandia landbridge hypothesis) or overwater dispersal.

Golden Orbweavers Ignore Biological Rules: Phylogenomic and Comparative Analyses Unravel a Complex Evolution of Sexual Size Dimorphism.

Instances of sexual size dimorphism (SSD) provide the context for rigorous tests of biological rules of size evolution, such as Cope's rule (phyletic size increase), Rensch's rule (allometric patterns of male and female size), as well as male and female body size optima. In certain spider groups, such as the golden orbweavers (Nephilidae), extreme female-biased SSD (eSSD, female:male body length $\ge$2) is the norm. Nephilid genera construct webs of exaggerated proportions, which can be aerial, arboricolous, or intermediate (hybrid).

Island biogeography and ecological modeling of the amblypygid in the Florida Keys archipelago.

Aim: The biogeography of terrestrial organisms across the Florida Keys archipelago is poorly understood. We used population genetics and spatioecological modeling of the Amblypygi to understand the genetic structure and metapopulation dynamics of Keys populations that are otherwise isolated by human development and ocean.

Location: The Florida Keys archipelago and mainland Florida.

Huntsmen of the Caribbean: Multiple tests of the GAARlandia hypothesis.

The origin of the Caribbean biota remains debated, but amassing evidence suggests important roles of both dispersal and vicariance events in the colonization the archipelago. The most prominent vicariance hypothesis is colonization over the GAARlandia land bridge that putatively connected the Greater Antilles to South America around 33 mya. This hypothesis has received support from studies of individual lineages, but its main prediction-the simultaneous colonization of multiple lineages during that time window-requires further unambiguous corroboration.

New species of Otiothopinae (Araneae: Palpimanidae) from Colombia.

Six new Colombian species of Otiothops (O. besotes sp. n.

Global mtDNA genetic structure and hypothesized invasion history of a major pest of citrus, (Hemiptera: Liviidae).

The Asian citrus psyllid Kuwayama is a key pest of citrus as the vector of the bacterium causing the "huanglongbing" disease (HLB). To assess the global mtDNA population genetic structure, and possible dispersal history of the pest, we investigated genetic variation at the gene collating newly collected samples with all previously published data. Our dataset consists of 356 colonies from 106 geographic sites worldwide.