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The tarantula skeletal muscle X-ray diffraction pattern suggested that the myosin heads were helically arranged on the thick filaments. Electron microscopy (EM) of negatively stained relaxed tarantula thick filaments revealed four helices of heads allowing a helical 3D reconstruction. Due to its low resolution (5.0 nm), the unambiguous interpretation of densities of both heads was not possible. A resolution increase up to 2.5 nm, achieved by cryo-EM of frozen-hydrated relaxed thick filaments and an iterative helical real space reconstruction, allowed the resolving of both heads. The two heads, “free” and “blocked”, formed an asymmetric structure named the “interacting-heads motif” (IHM) which explained relaxation by self-inhibition of both heads ATPases. This finding made tarantula an exemplar system for thick filament structure and function studies. Heads were shown to be released and disordered by Ca2+-activation through myosin regulatory light chain phosphorylation, leading to EM, small angle X-ray diffraction and scattering, and spectroscopic and biochemical studies of the IHM structure and function. The results from these studies have consequent implications for understanding and explaining myosin super-relaxed state and thick filament activation and regulation. A cooperative phosphorylation mechanism for activation in tarantula skeletal muscle, involving swaying constitutively Ser35 mono-phosphorylated free heads, explains super-relaxation, force potentiation and post-tetanic potentiation through Ser45 mono-phosphorylated blocked heads. Based on this mechanism, we propose a swaying-swinging, tilting crossbridge-sliding filament for tarantula muscle contraction.

We present a mtDNA gene tree of tarantula spiders (Araneae: Mygalomorphae: Theraphosidae) based on the mitochondrial 16S-tRNA (leu)-ND1 gene region as a promising initial molecular hypothesis to clarify the taxonomy of the largest subfamily, Theraphosinae. Many species of this New World subfamily are traded widely as exotic pets, yet few scientific studies on them exist, and the robustness of many supposed taxonomic groupings is debatable. Yet the validity of taxon names and knowledge of their distinctiveness is vital for trade regulation, most notably for the Neotropical genus Brachypelma Simon 1891, which is listed under CITES (Appendix II, see online supplemental material, which is available from the article's Taylor & Francis Online page at https://doi.org/10.1080/14772000.2017.1346719). The use of molecular markers for tarantula taxonomy has been limited until recently, with most previous studies relying on morphological methods. Our findings, from newly collected molecular data, have several nomencl...

Predation on earthworms is common in some generalist predator species, as for example several ground beetle species (Coleoptera: Carabidae) that frequently feed on earthworms. In spiders (Araneae), however, such behavior is far less well documented. A survey of reports on spiders feeding on earthworms yielded a total of 44 naturally occurring predation events. Spiders from 14 families were observed feeding on earthworms in nature, and species from two additional families consumed earthworm prey in captivity. Earthworm predation by spiders has been observed in temperate, subtropical, and tropical regions in 18 different countries. Tropical spiders from the families Theraphosidae (Mygalomorphae) and Ctenidae (Araneomorphae) accounted for 59% of the reported predation events. Reports from French Guiana document the capture of giant earthworms (0.6–1 m in length) by the giant tarantula, Theraphosa blondi (Latreille, 1804). Predation on giant earthworms by large tarantulas has also been observed in ra...

Males of the tarantula hawk wasp Hemipepsis ustulata defend individual trees and shrubs growing on ridges and peaks in the Sonoran Desert of Arizona. Territories occupied by males of this wasp species have been monitored in the Usery Mountains of central Arizona for nearly 4 decades. Although previous research indicated that males abandoned their territories by midday, in this study some territories continued to be occupied until as late as 1600h Mountain Standard Time (MST). Territories held into the afternoon included those that were taken early and late in the flight season and which were most-frequently occupied overall. Individual plants that were most likely to attract territorial males during five previous studies were also the most popular territories in 2016. Likewise, many other features of the territoriality of male tarantula hawks have usually been similar during most of the five previous studies of the wasps, including the tendency of larger males to occupy highly ranked territories ...

The genus Holothele Karsch, 1879 has a confusing taxonomic history, mainly due to a imprecise and outdated generic diagnosis, perpetuated since its original description. In this work, we propose a new diagnosis for the genus, redescribe the type species Holothele recta Karsch, 1879 and propose a few taxonomic changes. Holothele longipes is here considered as a senior synonym of Holothele recta Karsch, 1879, Stichoplastus sanguiniceps F. O. P.-Cambridge, 1898, Dryptopelmides rondoni Lucas & Bucherl, 1972, Dryptopelmides ludwigi Strand, 1907. We also provide updated geographic distribution records for Holothele longipes and propose the revalidation of Scopelobates Simon, 1903.

Voltage-gated sodium channels (NaVs) are activated by transiting the voltage sensor from the deactivated to the activated state. The crystal structures of several bacterial NaVs have captured the voltage sensor module (VSM) in an activated state, but structure of the deactivated voltage sensor remains elusive. In this study, we sought to identify peptide toxins stabilizing the deactivated VSM of bacterial NaVs. We screened fractions from several venoms and characterized a cystine knot toxin called JZTx-27 from the venom of tarantula Chilobrachys jingzhao as a high-affinity antagonist of the prokaryotic NaVs NsVBa (nonselective voltage-gated Bacillus alcalophilus) and NaChBac (bacterial sodium channel from Bacillus halodurans) (IC50 = 112 nM and 30 nM, respectively). JZTx-27 was more efficacious at weaker depolarizing voltages and significantly slowed the activation but accelerated the deactivation of NsVBa, whereas the local anesthetic drug lidocaine was shown to antagonize NsVBa without affecting channel gating. Mutation analysis confirmed that JZTx-27 bound to S3-4 linker of NsVBa, with F98 being the critical residue in determining toxin affinity. All electrophysiological data and in silico analysis suggested that JZTx-27 trapped VSM of NsVBa in one of the deactivated states. In mammalian NaVs, JZTx-27 preferably inhibited the inactivation of NaV1.5 by targeting the fourth transmembrane domain. To our knowledge, this is the first report of peptide antagonist for prokaryotic NaVs. More important, we proposed that JZTx-27 stabilized the NsVBa VSM in the deactivated state and may be used as a probe to determine the structure of the deactivated VSM of NaVs.-Tang, C., Zhou, X., Nguyen, P. T., Zhang, Y., Hu, Z., Zhang, C., Yarov-Yarovoy, V., DeCaen, P. G., Liang, S., Liu, Z. A novel tarantula toxin stabilizes the deactivated voltage sensor of bacterial sodium channel.

The genus Avicularia Lamarck, 1818 is revised and all species are rediagnosed. The type species, described as Aranea avicularia Linnaeus, 1758, is the oldest mygalomorph species described and its taxonomic history is extensive and confusing. Cladistic analyses using both equal and implied weights were carried out with a matrix of 46 taxa from seven theraphosid subfamilies, and 71 morphological and ecological characters. The optimal cladogram found with Piwe and concavity = 6 suggests Avicularia and Aviculariinae are monophyletic. Subfamily Aviculariinae includes Avicularia Lamarck, 1818, Typhochlaena C. L. Koch, 1850, Tapinauchenius Ausserer, 1871, Stromatopelma Karsch, 1881, Ephebopus Simon, 1892, Psalmopoeus Pocock, 1895, Heteroscodra Pocock, 1899, Iridopelma Pocock, 1901, Pachistopelma Pocock, 1901, Ybyrapora gen. n., Caribena gen. n., and Antillena gen. n. The clade is supported by well-developed scopulae on tarsi and metatarsi, greatly extended laterally. Avicularia synapomorphies are juveniles bearing black tarsi contrasting with other lighter articles; spermathecae with an accentuated outwards curvature medially, and male palpal bulb with embolus medial portion and tegulum’s margin form an acute angle in retrolateral view. Avicularia is composed of twelve species, including three new species: Avicularia avicularia (Linnaeus, 1818), Avicularia glauca Simon, 1891, Avicularia variegata (F. O. Pickard-Cambridge, 1896) stat. n., Avicularia minatrix Pocock, 1903, Avicularia taunayi (Mello-Leitão, 1920), Avicularia juruensis Mello-Leitão, 1923, Avicularia rufa Schiapelli & Gerschman, 1945, Avicularia purpurea Kirk, 1990, Avicularia hirschii Bullmer et al. 2006, Avicularia merianae sp. n., Avicularia lynnae sp. n., and Avicularia caei sp. n.. Avicularia species are distributed throughout Mexico, Costa Rica, Panama, Trinidad and Tobago, Venezuela, Guyana, Suriname, French Guiana, Colombia, Ecuador, Peru, Bolivia, and Brazil. Three new genera are erected to accommodate former Avicularia species: Caribena gen. n., composed of Caribena laeta (C. L. Koch, 1842), comb. n. and Caribena versicolor (Walckenaer, 1837), comb. n.; Antillena gen. n., with a single species, Antillena rickwesti (Bertani & Huff, 2013), comb. n., both from the Caribbean; and Ybyrapora gen. n., composed of Ybyrapora sooretama (Bertani & Fukushima, 2009), comb. n., Ybyrapora gamba (Bertani & Fukushima, 2009), comb. n. and Ybyrapora diversipes (C. L. Koch, 1842), comb. n. from Brazilian rainforest. The subspecies Avicularia avicularia variegata F. O. Pickard-Cambridge, 1896 is elevated to species status, resulting in the combination Avicularia variegata (F. O. Pickard-Cambridge, 1896) stat. n.. The following new synonymies are established: Avicularia velutina Simon 1889, Avicularia exilis Strand, 1907, Avicularia ancylochyra Mello-Leitão, 1923, Avicularia cuminami Mello-Leitão, 1930, and Avicularia nigrotaeniata Mello-Leitão, 1940 are junior synonyms of Avicularia avicularia; Avicularia bicegoi Mello-Leitão, 1923 is a junior synonym of Avicularia variegata stat. n., and Avicularia urticans Schmidt, 1994 is a junior synonym of Avicularia juruensis Mello-Leitão, 1923. Species transferred to other genera: Avicularia affinis (Nicolet, 1849) is transferred to Euathlus Ausserer, 1875, making the new combination Euathlus affinis (Nicolet, 1849), comb. n.; Avicularia subvulpina Strand, 1906 is transferred to Grammostola Simon, 1892, making the new combination Grammostola subvulpina (Strand, 1906), comb. n.; Avicularia aymara (Chamberlin, 1916) is transferred to Thrixopelma Schmidt, 1994, making the new combination Thrixopelma aymara (Chamberlin, 1916), comb. n.; Avicularia leporina (C. L. Koch, 1841) and Avicularia plantaris (C. L. Koch, 1842) are transferred to Iridopelma Pocock, 1901, making the new combinations Iridopelma leporina (C. L. Koch, 1841), comb. n. and Iridopelma plantaris (C. L. Koch, 1842), comb. n.; the two last species are considered nomina dubia. The following species are considered nomina dubia: Avicularia hirsutissima (C. L. Koch, 1842) nomen dubium; Ischnocolus hirsutum Ausserer, 1875 nomen dubium; Ischnocolus gracilis Keyserling, 1891 nomen dubium; Avicularia arabica (Strand, 1908) nomen dubium; Araneus hirtipes (Fabricius, 1787) nomen dubium; Avicularia ochracea (Perty, 1833) nomen dubium; Avicularia walckenaerii (Perty, 1833) nomen dubium; Avicularia testacea (C. L. Koch, 1841) nomen dubium; Avicularia detrita (C. L. Koch, 1842) nomen dubium; Ischnocolus doleschalli Ausserer, 1871 nomen dubium; Avicularia metallica Ausserer, 1875 nomen dubium; Avicularia rapax (Ausserer, 1875) nomen dubium; Avicularia holmbergi Thorell, 1890 nomen dubium; Avicularia aurantiaca Bauer, 1996 nomen dubium; Avicularia azuraklaasi Tesmoingt, 1996 nomen dubium; Avicularia huriana Tesmoingt, 1996 nomen dubium; Avicularia ulrichea Tesmoingt, 1996 nomen dubium; Avicularia braunshauseni Tesmoingt, 1999 nomen dubium; Avicularia geroldi Tesmoingt, 1999 nomen dubium; Avicularia soratae Strand, 1907 nomen dubium; Avicularia fasciculata Strand, 1907 nomen dubium; Avicularia fasciculata clara Strand, 1907 nomen dubium; and Avicularia surinamensis Strand, 1907 nomen dubium. Avicularia vestiaria (De Geer, 1778) is considered nomen nudum. Keys are provided for identification of all aviculariine genera, as well as to Avicularia, Caribena gen. n., Ybyrapora gen. n. and Antillena gen. n. species. Maps with records and information on species habitat are also presented. Lectotypes are newly designed for Avicularia avicularia, Avicularia variegata stat. n., Avicularia juruensis, Caribena laeta comb. n., Euathlus affinis comb. n. and a neotype is established for Caribena versicolor comb. n.

To report a case of tarantula hair-induced panuveitis treated with sustained-release intravitreal dexamethasone implant and followed by sequential spectral domain optical coherence tomography imaging.Findings on clinical examination, anterior segment optical coherence tomography, corneal in vivo confocal microscopy, color fundus photos, fluorescein angiography, and retinal spectral domain optical coherence tomography are presented. Sequential optical coherence tomography images demonstrated the course of the chorioretinal lesions before and after sustained-release intravitreal dexamethasone implant.A 19-year-old female presented with localized temporal episcleritis and scleritis that incompletely resolved despite multiple courses of topical and oral corticosteroids. She subsequently developed focal vitritis and chorioretinitis, and was found to have tarantula hair-induced panuveitis. Anterior segment optical coherence tomography and in vivo confocal microscopy confirmed the presence of tarantula hairs embedded in the anterior corneal stroma. There was only transient improvement with posterior sub-Tenon's Kenalog injection. After treatment with sustained-release intravitreal dexamethasone implant, her symptoms improved and the chorioretinal lesions became inactive. Sequential spectral domain optical coherence tomography images revealed hyperreflective inner retina lesions that progressed to involve the outer retina, and then flattened to near resolution after therapy.This is the first case showing positive clinical outcomes supported by sequential retinal spectral domain optical coherence tomography using a sustained-release intravitreal dexamethasone implant to treat ophthalmia nodosa-induced by tarantula hairs.

There have been increasing reports of cases of erratic movements and ataxia followed by death in tarantula species. This paper covers a brief review of what we know about the condition and what to ...

Spiders belong to the class Arachnida in the phylum Arthropoda. Although the bite of the spider is feared as much as that of venomous snakes in Sri Lanka, spider bite related deaths are not reported in this country. A 43-year-old patient presented with local swelling, pain, bleeding from puncture site and muscle cramps after a Poecilotheria subfusca (Ivory-billed ornamental or montane tiger spider) bite; and a 45-year-old patient presented with numbness, burning pain and muscle cramps after a Poecilotheria fasciata (Ceylon Hunting Spider/Ornamental Tarantula) bite. Both patients recovered completely without residual effects.

Power feeding in tarantulas is often practised by hobbyist keepers, but the results of this feeding regimen have not been well documented. To determine the effects of power feeding on growth rates, we separated two groups (A and B) of newly hatched Honduran Curly Hair tarantula (Brachypelma albopilosum Valerio, 1980) spiderlings and fed individuals two different diets. Group B (n = 50) was fed two crickets (Acheta domesticus) per week while group A (n = 50) was fed one cricket per week. Tarantulas exhibited a logistic growth curve and we found significant differences in growth rate and instar size when comparing the two groups. Group B tarantulas were significantly larger at each instar than group A tarantulas. This finding indicates that power-fed tarantulas grow at a faster rate, which suggests increased fecundity for females, though obesity may result from such a diet and impact tarantula fecundity, sexual maturity, and/or lifespan. These topics should be explored in subsequent studies.

Introduction. The aim of this paper was to present a case of keratouveitis caused by casual handling of a tarantula. Tarantulas, including the Grammostola rosea (Chilean rose), have barbed irritant or urticating hairs, which may be shed during casual handling and in contact with the eye migrate to different parts of the eye and cause inflammatory response known as ophthalmia nodosa. Case outline. A 15-year-old boy presented to our department with a sudden onset of a sore, red left eye, which he noticed after handling his tarantula pet. Slit-lamp examination of the left eye revealed ciliary injection and multiple hairs in all corneal layers. Topical antibiotic and corticosteroid treatment was commenced and there was initial improvement in his clinical status. Three weeks after the initial presentation he developed uveitis and mild macular oedema in his left eye and the best corrected visual acuity in the left eye was reduced. Only local corticosteroid treatment was continued and there was improvement in both the best corrected visual acuity and clinical status of the left eye, while the corneal hairs had not migrated and were still present in all corneal layers despite of long-term tapering regimen of topical steroid therapy. Conclusion. Handling of these increasingly popular exotic pets requires special precautionary measures.

Made available in DSpace on 2020-12-10T19:42:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-11-19 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) The tarantula genus Tmesiphantes Simon, 1892 (Theraphosinae) includes nine valid species, with records for the states of Bahia (T. nubilus, T. caymmii, T. amadoi, T. bethaniae, T. hypogeus, and T. mirim), Minas Gerais (T. perp and T. riopretano), and Para (T. aridai), all in Brazil. In the present study, we reviewed the taxonomy of the Tmesiphantes species and performed a phylogenetic analysis using morphological characters. Four new species are described: T. amazonicus sp. nov., T. guayarus sp. nov., T. nordestinus sp. nov., and T. raulseixasi sp. nov., which expand the geographic distribution for the following states in Brazil: Goias, Mato Grosso, Piaui, Paraiba, and Pernambuco, occurring in the Caatinga shrublands Cerrado savannas, Atlantic rain forest, and Brazilian Amazon. Phylogenetic analysis included 30 terminal taxa and 37 characters, including representatives of nine genera of Theraphosinae. The Tmesiphantes species formed a monophyletic group with the species hitherto included in Melloleitaoina and Magulla, with the latter being paraphyletic, which led us to propose the synonymy of these three genera. An updated diagnosis is proposed for the genus Tmesiphantes, which now comprises 19 species, occurring in major Brazilian biomes and in Argentina. A distribution map that includes all Tmesiphantes species and notes on their distributions are provided. Univ Fed Paraiba, Dept Sistemat & Ecol, Ctr Ciencias Exatas & Nat, Campus 1,Cidade Univ, BR-58050970 Joao Pessoa, Paraiba, Brazil Univ Estadual Paulista, Dept Zool, Inst Biociencias, Av 24 A,1515, BR-13506900 Rio Claro, SP, Brazil Univ Estadual Paulista, Dept Zool, Inst Biociencias, Av 24 A,1515, BR-13506900 Rio Claro, SP, Brazil CAPES: CAPES - 24001015029P6

Mygalomorph spiders of the family Theraphosidae, known to the broader public as tarantulas, are among the most recognizable arachnids on earth due to their large size and widespread distribution. Their use of urticating setae is a notable adaptation that has evolved exclusively in certain New World theraphosids. Thus far, the evolutionary history of Theraphosidae remains poorly understood; theraphosid systematics still largely relies on morphological datasets, which suffer from high degrees of homoplasy, and traditional Sanger sequencing of preselected genes failed to provide strong support for supra-generic clades. In this study, we provide the first robust phylogenetic hypothesis of theraphosid evolution inferred from transcriptome data. A core ortholog approach was used to generate a phylogeny from 2460 orthologous genes across 25 theraphosid genera, representing all of the major theraphosid subfamilies, except Selenogyrinae. Our phylogeny recovers an unprecedented monophyletic group that comprises the vast majority of New World theraphosid subfamilies including Aviculariinae, Schismatothelinae and Theraphosinae. Concurrently, we provide additional evidence for the integrity of questionable subfamilies, such as Poecilotheriinae and Psalmopoeinae, and support the non-monophyly of Ischnocolinae. The deeper relationships between almost all subfamilies are confidently inferred. We also used our phylogeny in tandem with published morphological data to perform ancestral state analyses on urticating setae, and contextualize our reconstructions with emphasis on the complex evolutionary history of the trait. © 2019 Elsevier Inc.

The tarantula spider genus Aphonopelma Pocock, 1901 has received considerable attention in recent years but the group’s diversity remains poorly understood in Mexico, particularly in the pine-oak woodlands of the Sierra Madre Occidental and associated Madrean “Sky Islands”. A pair of tarantulas discovered from an unsampled region in the Sierra de Bacadéhuachi (the westernmost range of the Sierra Madre Occidental) in northeastern Sonora was found to be closely related to four species from the Madrean “Sky Islands” in Arizona and New Mexico. An integrative approach for delimiting species (incorporating data from molecular phylogenetics, morphology, distributions, and breeding periods) suggests that the specimens from Sierra de Bacadéhuachi belong to an undescribed species that is herein named Aphonopelma bacadehuachi sp. nov. This new species adds to our knowledge of an increasingly diverse assemblage of Aphonopelma from the Madrean Pine-Oak Woodlands Hotspot. Collaborations between Mexican and American researchers are needed to accelerate discovery and description of the group’s remaining diversity, particularly in light of the many threats facing the ecoregion including habitat degradation and climate change.

Made available in DSpace on 2019-10-06T16:47:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-11-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Theraphosid spiders are repleted with cuticular structures that evolved into distinct morphologies and developed different functions. The stridulatory apparatus present in the subfamily Theraphosinae is composed by a group of setae and opposed organs (ridged surface) that emit sound through friction. Only sixteen genera of Theraphosinae spiders were reported with stridulatory setae: Acanthoscurria, Aguapanela, Brachypelma, Citharacanthus, Cyrtopholis, Grammostola, Hemirrhagus, Lasiodora, Longilyra, Nhandu, Theraphosa, Pamphobeteus, Phormictopus, Proshapalopus, Pterinopelma and Vitalius. Besides these stridulating setae, other cuticular structures have been traditionally used in Theraphosinae taxonomy: the plumose scopula on the lateral faces of femora I and IV. However, the ultrastructure of these setae and scopulae was never studied in detail. Here, we analyzed the diversity of cuticular structures on coxae, trochanters and femora of Theraphosinae spiders using SEM. Beside the description of plumose and claviform stridulating setae on femora, we established five distinct variations of stridulatory setae found on coxae and trochanters and report their presence for the genus Megaphobema, Crassicrus and Cotztetlana for the first time. Department of Zoology Institute of Biosciences São Paulo State University (UNESP – Rio Claro) Department of Zoology Institute of Biosciences São Paulo State University (UNESP – Rio Claro) CNPq: 168493/2017-9 FAPESP: 2017/11985-9 CAPES: 479377/2012-0

Aphonopelma braunshausenii Tesmoingt, 1996 is regarded as a nomen dubium due to the lack of a deposited holotype, an inadequate description which gives no stable taxonomic features to differentiate it from any other species and the absence of an exact type locality. The instability of some morphological characters which were given weight for species delineation in many earlier works is discussed and illustrated.

Submitted by Everton Fernando Trova (everton.trova@unesp.br) on 2022-01-26T11:46:10Z No. of bitstreams: 1 dissertação_mest_Everton_Fernando_Trova.pdf: 4739915 bytes, checksum: f9c1af090451a3bfc5c84f28390e05b4 (MD5) Approved for entry into archive by Adriana Ap. Puerta Buzzá (dripuerta@rc.unesp.br) on 2022-01-26T13:33:25Z (GMT) No. of bitstreams: 1 trova_ef_me_rcla.pdf: 4739915 bytes, checksum: f9c1af090451a3bfc5c84f28390e05b4 (MD5) Made available in DSpace on 2022-01-26T13:33:25Z (GMT). No. of bitstreams: 1 trova_ef_me_rcla.pdf: 4739915 bytes, checksum: f9c1af090451a3bfc5c84f28390e05b4 (MD5) Previous issue date: 2019-04-26 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Araneae é uma ordem bastante diversificada, sendo uma linhagem com grande sucesso evolutivo. A infraordem Mygalomorphae representa uma pequena porção da ordem Araneae e são animais sedentários que passam grande parte do dia em refúgios climaticamente estáveis. As aranhas-de-alçapão passam toda a vida ou parte dela dentro de uma toca revestida com seda e dotada de um opérculo. Local onde realizam todas as necessidades, caçam por emboscada, se alimentam, se reproduzem e realizam ecdise. Este trabalho teve como objetivo esclarecer alguns aspectos sobre a história natural das aranhas-de-alçapão e avaliar o perfil térmico e umidade nas áreas estudadas. Os resutados foram divididos em dois capítulos: I. A morfologia da toca e opérculo foram descritos, bem como a presença de ornamentos e o comportamento de defesa quando perturbadas em suas tocas. As variáveis morfológicas foram correlacionadas com o diâmetro da toca em questão. As áreas em que as aranhas-de-alçapão ocorrem apresentaram diferenças na vegetação. As tocas sendo os principais locais em que as aranhas passam parte da vida, em conjunto com a vegetação oferecem micro-habitats adequados e permite que as aranhas vivam por vários anos sem a necessidade de emigrar. A permanência no interior da toca evita contato direto com o meio externo reduzindo riscos de predação e com grandes variações climáticas podendo leva-las a morte. II. As áreas com a presença de aranhas-de-alçapão tiveram diferenças significativas com as áreas com ausência, quanto a temperatura e umidade. Áreas com presença foram mais úmidas e apresentaram um padrão de temperatura vertical (gradiente térmico) no solo. O gradiente térmico encontrado na área com presença e a umidade são caraterísticas que permitem as aranhas manter a temperatura e umidade corporal em equilíbrio evitando assim estress térmico e hídrico. Araneae is a very diverse order, being a lineage with great evolutionary success. The Mygalomorphae infraorder represents a small portion of the Araneae order and are sedentary animals that spends much of the day in climatically stable refuges. Trapdoor spiders spend all or part of their lives in a burrow lined with silk and closed with an trapdoor. The place where they carry out all their needs, they hunt by ambush, feed, reproduce and perform ecdysis. This work aimed to clarify some aspects of the natural history of trapdoor spiders and evaluate the thermal profile and moisture in the areas studied. The results were divided into two chapters: I. The morphology of the burrow and trapdoor were described, as well as the presence of ornaments and the defense behavior when disturbed in its burrows. The morphological variables were also correlated with the diameter of the burrow in question. The areas in which trapdoor spiders occur showed differences in vegetation. The barrows being the main places of their lives, together with the vegetation provide suitable microhabitats and allows spiders to live for several years without the need to migrate. The stay inside the burrow avoids direct contact with the external environment reducing risks of predation and with great climatic variation that can lead to death. II. The areas with trapdoor spiders had significant differences with the areas with no trapdoor spiders in terms of temperature and humidity. Areas with presences were more humid and presented pattern vertical temperature (thermal gradient) in the ground. The thermal gradient found in the area with presence and moisture are characteristics that allow the spider to maintain the temperature and body humidity in balance thus avoiding thermal and water stress. CAPES: 001.

Theraphosid spiders (tarantulas) are venomous arthropods found in most tropical and subtropical regions of the world. Most Australian tarantula species were described more than 100 years ago and there have been no taxonomic revisions. Seven species of theraphosids are described for Australia, pertaining to four genera. They have large geographic distributions and they exhibit little morphological variation. The current taxonomy is problematic, due to the lack of comprehensive revision. Like all organisms, tarantulas are impacted by numerous environmental factors. Their venoms contain numerous peptides and organic compounds, and reflect theraphosid niche diversity. Their venoms vary between species, populations, sex, age and even though to maturity. Tarantula venoms are complex cocktails of toxins with potential uses as pharmacological tools, drugs, and bioinsecticides. Although numerous toxins have been isolated from venoms of tarantulas from other parts of the globe, Australian tarantula venoms have been little studied. Using molecular methods, this thesis aims to document venom variation among populations and species of Australian tarantulas and to better describe their biogeography and phylogenetic relationships.The phylogenetic species delimitation approach used here predicts a species diversity two to six times higher than currently recognized. Species examined fall into four main clades and the geographic disposition of those clades in Australia seems to be related to precipitation and its seasonality. Australian tarantulas are shown to be non-monophyletic. Species may have immigrated multiple times between South-east Asia (SEA) and Australia.Australian species belonging to the genera Phlogius and Coremiocnemis are shown to be paraphyletic. However, the inclusion of “true” Selenocosmia species, e.g., from southeast Asia, is necessary to make more sound decisions regarding synonyms and diagnoses. Haplotypes of P. crassipes reveals highly genetically structured genes and the absence of isolation by distance. Phlogius crassipes is composed of at least two cryptic species, and here its range and diagnosis are updated. Phlogius strenuus is transferred from Selenocosmia and its range and diagnosis are updated. With the new range of Phlogius strenuus, it is clear that populations, genetic diversity, and even entire species are at risk, based upon the assumption that the species might be harvested sustainably is rejected.I found 26 phylogenetic clades using 2% divergence of the nucleotides of the 16S barcode region. Using whole venom profiling, the venom of individuals within a clade varies as much as across clades. However, venom belonging to phylogenetic groups contained at least one unique peptide that could be utilised to distinguish it from other phylogenetic groups. These results suggest that venom variation between phylogenetic groups may be useful in ascertaining species identity. I show that the venom of P. strenuus changes continuously during development and throughout adulthood, i.e., there are ontogenetic changes in venom composition.Intraspecific and interspecific venom variation can demonstrate how fast evolving and adaptive venom can be. The presence of unique peptides within each phylogenetic group is evidence that the specificity of venom could be used as an identification method in future. In addition, unique peptides within potential species and within each maturity stage present extra evidence that a single species can highly contribute to amplify our chemical library, which can increase possibilities of making new pharmacological discoveries.

Grammostola vachoni es una tarántula endémica y nativa de Argentina, categorizada en estado Vulnerable según la UICN. Se distribuye principalmente en el centro del país ocupando áreas montañosas o serranas de pastizal. Posee características particulares, por ejemplo, presenta mecanismos de dispersión limitados, distribución agregada, madurez sexual tardía y en el caso de las hembras una vida muy longeva y sedentaria. Estas características junto con la actual retracción al que está sometido su hábitat, hacen que la especie presente mayor vulnerabilidad. El objetivo general de esta tesis fue producir conocimientos ecológicos y biológicos para contribuir a la conservación de G. vachoni. Para ello se abordaron objetivos particulares tanto en laboratorio como a campo. En laboratorio se realizó la descripción de las etapas de desarrollo en individuos y el estudio de los caracteres sexuales primarios de las hembras, además se estimó el rendimiento alimentario, la preferencia de presas, las temperaturas preferidas y el efecto de las temperaturas extremas en el rendimiento de la especie. En estudios a campo se describió la arquitectura de las cuevas, los hábitos de actividad y de fidelidad al refugio, como así también se compararon los microambientes seleccionados por G. vachoni bajo diferentes tipos de disturbios. A modo de proyección se modeló la distribución geográfica potencial de la especie mediante perfiles bioclimáticos actuales y futuros. A partir de los resultados obtenidos se concluye que los individuos presentan un desarrollo más lento que lo registrado para otras especies de tarántulas, con crecimiento alométrico positivo de los caracteres sexuales primarios de las hembras. Tanto el rendimiento alimentario como la frecuencia de alimentación obtenida para G. vachoni son similares a los de otras tarántulas y demuestra que son capaces de pasar un tiempo prolongado sin alimentación. Además, se obtiene evidencia que ciertas presas brindan mayor ganancia energética. Las temperaturas preferidas fueron diferentes en individuos aclimatados y no aclimatados demostrando que existe un efecto directo de la temperatura sobre el comportamiento de la especie. Se encontró que la abundancia y la distribución de los individuos varía entre sitios con diferente grado de disturbio, siendo los ambientes con invasión de especies leñosas exóticas y las áreas con acceso al turismo los ambientes menos adecuados para el desarrollo de la especie. No se registraron efectos directos de la preferencia del hábitat según la composición del suelo, pero se encontró que tanto la composición de especies vegetales como la heterogeneidad y la diversidad de la comunidad vegetal son influenciadas por los diferentes regímenes de disturbio, alterando la distribución de las arañas. Las proyecciones climáticas a futuro según diferentes escenarios de cambio climático global muestran una firme retracción en la distribución de G. vachoni, persistiendo sólo en pequeños y aislados relictos de ambientes adecuados para el desarrollo de la especie.En esta tesis se propone la utilización de G. vachoni como bioindicador de la condición del pastizal serrano y se exponen las preferencias y limitaciones de la especie con el fin de aportar conocimientos para su conservación. Grammostola vachoni is an endemic tarantula native to Argentina, included in the Red List of the IUCN under the "vulnerable" category. It is distributed mainly in grasslands in the mountain systems of central Argentina. Grammostola vachoni has particular characteristics as limited dispersion mechanisms, aggregate distribution, late sexual maturity and females with long and sedentary life. These characteristics and the real retraction to the natural environment, make the species more vulnerable. The general goal of this Thesis is the production of ecological and biological knowledge to contribute to the conservation of G. vachoni. For this, it was released particular goals in laboratory and field. In the laboratory were described a development for stages of individuals and the apparition of primary sexual characters in immature females. In addition, was studying the feeding performance, the temperatures preferences and the effect of the extreme temperatures. In the field, were described the borrows architecture, the activity habits and the refuge fidelity. Also, we performed a characterization of the microhabitat of G. vachoni at sites with different disturbance regimes and we analyzed the potential use of this species as a bioindicator of mountain grassland condition. As projection was modeled the potential geographic distribution through current and future bioclimatic profiles. From the obtained results, I concluded that individuals present slower development that the recorder for other tarantula’s species, and it was registered a positive allometric grown of the primary sexual characters. Feeding performance and feeding frequency were similar to the other tarantulas and shown that G. vachoni are able to spend a long time without food. Also, it was evident the different energy gains among the prey type. The preferred temperatures were different in acclimated and non-acclimated individuals and revealed a direct effect for temperature on the species behavior. It found significant differences in the number of individuals and the percentage of occupation between sites with different degrees of disturbance. No significant differences were recorded in the soil characteristics and occupation of G. vachoni but we found that the composition of vegetation and the heterogeneity and diversity of plants are influenced by different disturbance regimes, altering the distribution of spiders. Environments with an invasion of exotic woody trees and areas with access to tourism were the least suitable environments for the development of the species. The climatic projections for a future in different scenarios of climate global change shown a strong retraction in the distribution of G. vachoni populations, persisting only some small and isolated relicts of suitable environments for the development of species. The information reported in this Thesis is very important to provide data for a future re-categorization of G. vachoni for the Red List of IUCN. Also, we add a new component of ecosystems for to use as indicator, open up the possibility for new research for the same and other species of a grassland of the mountainous system. Fil: Schwerdt, Leonela Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina

This is the first study about trophic traits of Grammostola vachoni, a threatened theraphosid spider endemic to the mountain systems of central Argentina. Four prey types were used in experiments: crickets, cockroaches, beetle larvae and adult beetles. Grammostola vachoni was observed to eat at a rate of about once every 11 days, with the mean total number of prey consumed per spider during the experimental period being 2.7. Latency to the first attack was similar for crickets, cockroaches and beetle larvae, but was shorter for adult beetles. Feeding time was significantly longer for crickets and beetle larvae. Mass gain was significantly different among prey types. Feeding effectiveness and ingestion rate were significantly higher for crickets. A significant positive correlation for feeding effectiveness and ingestion rate with prey mass and the initial spider mass was also found. Fil: Schwerdt, Leonela Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina Fil: Pompozzi, Gabriel Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: de Villalobos, Ana Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina Fil: Pérez Miles, Fernando. Universidad de la República. Facultad de Ciencias; Uruguay

The spider subfamily Schismatothelinae from Colombia is revised. One new species of Euthycaelus Simon 1889 and three new species of Schismatothele Karsch 1879 are named, as well as new geographical records provided. E. guane sp. nov. from Santander, S. hacaritama sp. nov. from Norte de Santander, S. olsoni sp. nov. from Norte de Santander and Táchira (Venezuela), and S. weinmanni sp. nov. from Cundinamarca are herein described, diagnosed and illustrated. Schismatothele is newly recorded from Colombia. Morphological aspects and diversity of the Ischnocolinae and Schismatothelinae from Colombia are discussed. An identification key to species of these subfamilies from Colombia is provided.

A new species of Ami Pérez-Miles, 2008 is described from the state of Amazonas in Brazil based on three males from Manaus. Ami valentinae sp. nov. is closely related to A. armihuariensis and A. caxiuana by the presence of a granular area on the embolus, but it differs from the first species by the presence of two retrolateral process on the male palpal tibia and differs by the latter by the morphology of the male palpal organ. A. valentinae sp. nov. is the first species of Ami reported for the Amazonas state and second species described for Brazil. © TÜBİTAK.

Mygalomorph spiders of the family Theraphosidae, known to the broader public as tarantulas, are among the most recognizable arachnids on earth due to their large size and widespread distribution. Their use of urticating setae is a notable adaptation that has evolved exclusively in certain New World theraphosids. Thus far, the evolutionary history of Theraphosidae remains poorly understood; theraphosid systematics still largely relies on morphological datasets, which suffer from high degrees of homoplasy, and traditional targeted sequencing of preselected genes failed to provide strong support for supra-generic clades (i.e. particularly those broader than subfamilies). In this study, we provide the first robust phylogenetic hypothesis of theraphosid evolution inferred from transcriptome data. A core ortholog approach was used to generate a phylogeny from 2460 orthologous genes across 25 theraphosid genera, representing all of the major theraphosid subfamilies, except Selenogyrinae. For the first time our phylogeny recovers a monophyletic group that comprises the vast majority of New World theraphosid subfamilies including Aviculariinae and Theraphosinae. Concurrently, we provide additional evidence for the integrity of questionable subfamilies, such as Poecilotheriinae and Psalmopoeinae, and support the non-monophyly of Ischnocolinae. The deeper relationships between almost all subfamilies are confidently inferred for the first time. We also used our phylogeny in tandem with published morphological data to perform ancestral state analyses on urticating setae. This revealed that the evolution of this important defensive trait might be explained by three equally parsimonious scenarios.

A new species, Scaphosepalum tarantula, is described. It is recognized by the medium-sized plants with grey-green leaves suffused with red-brown to purple stains at the petioles; densely fimbriated, red-brown to sanguine flowers, spiky tails of the lateral sepals and a dark sanguine, wingless lip. It is here compared to Scaphosepalum fimbriatum with which it shares similarities. Resumen Se describe aquí Scaphosepalum tarantula, una nueva especie. Se reconoce por las plantas de tamaño mediano con hojas verde-gris salpicadas por manchas rojo-café en los peciolos; las flores densamente fimbriadas, café-rojizo a color sangre, con las caudas de los sépalos laterales con púas y el labelo sin alas. Se lo compara con Scaphosepalum fimbriatum, con el que comparte rasgos similares.

Voltage-gated sodium channels initiate electrical signals and are frequently targeted by deadly gating-modifier neurotoxins, including tarantula toxins, which trap the voltage sensor in its resting state. The structural basis for tarantula-toxin action remains elusive because of the difficulty of capturing the functionally relevant form of the toxin-channel complex. Here, we engineered the model sodium channel NaVAb with voltage-shifting mutations and the toxin-binding site of human NaV1.7, an attractive pain target. This mutant chimera enabled us to determine the cryoelectron microscopy (cryo-EM) structure of the channel functionally arrested by tarantula toxin. Our structure reveals a high-affinity resting-state-specific toxin-channel interaction between a key lysine residue that serves as a "stinger" and penetrates a triad of carboxyl groups in the S3-S4 linker of the voltage sensor. By unveiling this high-affinity binding mode, our studies establish a high-resolution channel-docking and resting-state locking mechanism for huwentoxin-IV and provide guidance for developing future resting-state-targeted analgesic drugs.

A 9 yr old rat terrier presented with corneal ulceration and conjunctivitis that developed acutely after digging among dry leaves in wooded northern Arizona. Ophthalmic examination revealed multiple linear foreign bodies throughout the adnexal tissue and cornea of the left eye. Manual removal of material was unsuccessful. The palpebral conjunctiva required excision with tenotomy scissors to remove structures and allow corneal healing. Microscopic examination revealed structures believed to be setae from a Theraphosidae tarantula. This was confirmed morphologically by an entomologist and by comparison with hairs from a captive spider of the suspected species. The excised tissue also contained fruiting bodies, hyphae, and microconidia consistent with Aspergillus spp. The captive spider hairs also cultured positive for Aspergillus, suggesting a relationship between this fungus and tarantulas in captivity and in their native habitat. This is the first report in the veterinary literature to confirm tarantula hair as the causative agent in keratoconjunctivitis and corneal ulceration, adding it to the list of differential diagnoses for ocular foreign body. This is also the first report to suggest a relationship between Aspergillus and tarantulas of the Theraphosidae family, which should be considered in the diagnostics and treatment of patients with suspected tarantula hair keratoconjunctivitis.

Silks and silk-producing organs of the theraphosid species Avicularia metallica were studied using scanning electron microscopy. The spinning apparatus is made up of two pairs of spinnerets located at the end of the ventral side of the opisthosoma. Both pairs of spinnerets are equipped with spigots (modified setae), i.e. external outlets of silk-producing glands which, in the case of posterior lateral spinnerets, are present on all three segments.The secreted silk, which hardens when exposed to air, is processed by movements of spinnerets and the opisthosoma. An investigation of spinning activity revealed two different manners in which silk is affixed to the ground: (1) by smearing silk secretion directly onto the surface of the substratum; or (2) by attaching silken fibers onto a layer of adhesive silk of attachment fields. The fibers connecting the walls of tubular shelters to the silk of attachment fields are essentially bundles of parallel nanofibrils. The connection between multifibrillar connecting fibers and the adhesive silk of attachment fields is, in essence, “silk-to-silk” connection. Nanoglobules (spherical subunits) are the basic microstructural blocks in the studied silk materials irrespective of whether the fibrils are a part of the tube, connecting fibers, or attachment fields. SEM images showed that the liquid silk, running through spigot ducts, has two components, which do not mix as they leave the spigots. The peripheral component of the solidified protein mixture surrounds the central component, which has a granular appearance

Tarantulas are a relatively unstudied category of invertebrate which are popular with hobbyists and increasingly used in laboratory research. As their presence in the veterinary setting is limited, very little is known about the biochemistry of their haemolymph as obtained by in house sampling and analysis. A handful of studies have been performed to attempt to establish a normal range for certain parameters in healthy members of a few particular species, but that is the extent of the current research. In this study, 12 tarantulas of the Nhandu chromatus species purchased as immature siblings and kept under standardised conditions for 2.5 years were anaesthetised with isoflurane and had 0.2 ml of haemolymph sampled and analysed for: total protein, glucose, calcium, phosphorous and uric acid. As well as having kept a diary of their daily feed intake and recorded dates of ecdysis, the exposure time to anaesthetic and perceived effectiveness were recorded. The variables originally proposed for this investigation are based on 2 separate feeding regimes, differing in terms of feed quantity and the effect on the aforementioned biochemical parameters. Upon receipt of the biochemical results from the first sampling, it became apparent that unexpected correlations could be made between the stage of ecdysis, susceptibility to anaesthesia and the total protein levels in the haemolymph. Those that were due to shed imminently, indicated by cessation in feeding, had recognisably and significantly higher total protein levels and reached a better level of anaesthesia in less time. Additional samplings are planned in the future to specify more definitive parameters. The observations made inadvertently so far could constitute novel information and be practically useful to tarantula enthusiasts and anaesthetists, and therefore, potentially of high clinical significance.

The spider fly genus Eulonchus Gerstaecker is found throughout the Nearctic Region. Six species are recognized and intraspecific morphological variation is documented in several species. A phylogeny of Eulonchus based on DNA sequence data of three molecular markers (COI, CAD, and 16S) is presented and relationships of species are discussed in the light of biogeography and host usage. All six species of Eulonchus are redescribed using natural language descriptions exported from a character matrix, and a key to species is presented. Lectotypes are designated for Eulonchus sapphirinus Osten Sacken, Eulonchus smaragdinus Gerstaecker, and Eulonchus tristis Loew.

Tarantulas and hermit crabs are commonly kept pets and are underappreciated in veterinary medicine. Safe handling, biology and husbandry, diagnostic techniques, anesthesia, fluid therapy, disorders, and euthanasia are covered in this article. Current research is applied to these topics to keep practitioners abreast with the best medicine for these creatures.

Spiders have a great potential to prey on small vertebrates. However, detailed events are sparse in the literature. In the current work, two detailed records of Tarantula predation in the Brazilian Amazon are documented. Preying begins by bird’s eyes, which eases the inoculation and spread of the digestive enzymes. Maria Sibylla Merian described the predation of a bird by a Tarantula in a scientific illustration, though her descriptions were labeled as fanciful. The current work makes a small homage to this 17th Century naturalist that challenged the prejudice of her time with her artistic and scientific production.

The mygalomorph genus Grammostola (family Theraphosidae) is endemic to South America. The species Grammostola anthracina is one of the largest spiders in Uruguay and reputed to be the longest lived tarantula in the world. This nominal species has two distinct colour morphs comprising black and reddish-brown forms with controversial taxonomic status. Here, we present a phylogenetic study based on molecular characters (cytochrome c oxidase subunit I) of haplotypes of G. anthracina and closely related species. Our analysis together with new morphological data and biogeographical information indicates that the two morphs of G. anthracina constitute different species that are not sister to each other. Consequently, a new species, Grammostola quirogai is described, diagnosed and illustrated to encompass the black morph. Phylogenetic relationships and new taxonomic characters for Grammostola species included in this study are discussed.

Introduction Tarantulas belonging to the Theraphosidae family are more and more popular as family pets. Ocular injuries caused by tarantulas are reported in several articles. We hereby report the first known case of ocular injury caused by a tarantula in China and observed by anterior segment optical coherence tomography (AS-OCT). Case A 22-year-old girl was referred to our hospital with one-week history of red and irritated left eye after she grabbed her molting Chilean Rose Tarantula. Her best-corrected visual acuity was 20/20 on both eyes. Her left eyelid was slightly red and edema. Slit-lamp examination found that more than a dozen of microscopic barbed hairs embedded into the cornea. AS-OCT showed that barbed hairs embedded in the cornea in different direction and the length of the hairs ranged from 173 μm to 395 μm. The anterior chamber was quiet with normal fundus and intraocular pressure. Topical steroid treatment was prescribed and the response was good. No corneal opacity or intraocular inflammation was observed after topical steroid treatment for one month. Conclusions As exotic pets become more and more popular, the importance of wearing ocular protection when handling tarantulas should be emphasized when they are sold. Tarantulas are unsuitable pet for children. When a patient presents with an unusual red eye, pet-keeping history, spiders included, should be asked.

A bilateral gynandromorph specimen of the tarantula Pterinochilus murinus Pocock, 1897 is here described and illustrated. In addition, encounters with conspecific females were studied. The possible explanations for this case of gynandry are discussed. This constitutes the first formal report of gynandry in a mygalomorph spider.

Sonoran Desert toads (Incilius alvarius) are known to consume invertebrates, small lizards, other toads, and mice. Here we report an attempt by a Sonoran Desert toad to consume a western desert tarantula (Aphonopelma chalcodes) at Sabino Canyon, Arizona. Despite nearly being completely swallowed, the tarantula was able to escape after a struggle lasting ≥50 s, likely due to defensive bites and urticating hairs.