Sphingomyelinase D Activity in Sicarius tropicus Venom: Toxic Potential and Clues to the Evolution of SMases D in the Sicariidae Family.

The spider family Sicariidae includes three genera, Hexophthalma, Sicarius and Loxosceles. The three genera share a common characteristic in their venoms: the presence of Sphingomyelinases D (SMase D). SMases D are considered the toxins that cause the main pathological effects of the Loxosceles venom, that is, those responsible for the development of loxoscelism. Some studies have shown that Sicarius spiders have less or undetectable SMase D activity in their venoms, when compared to Hexophthalma. In contrast, our group has shown that Sicarius ornatus, a Brazilian species, has active SMase D and toxic potential to envenomation. However, few species of Sicarius have been characterized for their toxic potential. In order to contribute to a better understanding about the toxicity of Sicarius venoms, the aim of this study was to characterize the toxic properties of male and female venoms from Sicarius tropicus and compare them with that from Loxosceles laeta, one of the most toxic Loxosceles venoms. We show here that S. tropicus venom presents active SMases D. However, regarding hemolysis development, it seems that these toxins in this species present different molecular mechanisms of action than that described for Loxosceles venoms, whereas it is similar to those present in bacteria containing SMase D. Besides, our results also suggest that, in addition to the interspecific differences, intraspecific variations in the venoms' composition may play a role in the toxic potential of venoms from Sicarius species.

Searching for the toxic potential of Loxosceles amazonica and Loxosceles willianilsoni spiders' venoms.

The Loxosceles genus belongs to the Sicariidae family and it comprises species whose venom can cause accidents with potentially fatal consequences. We have previously shown that SMase D is the enzyme responsible for the main pathological effects of Loxosceles venom. Despite the severity of accidents with Loxosceles, few species are considered to be of medical importance. Little is known about the venom of non-synanthropic species that live in natural environments. To contribute to a better understanding about the venom's toxicity of Loxosceles genus, the aim of this study was to (i) characterize the toxic properties of Loxosceles amazonica from two different localities and a recent described cave species Loxosceles willianilsoni and (ii) compare these venoms with that from Loxosceles laeta, which is among the most toxic ones. We show here that both L. amazonica venoms (from the two studied locations) and L. willianilsoni presented SMase D activity similar to that exhibited by L. laeta venom. Although L. amazonica and L. willianilsoni venoms were able to induce complement dependent human erythrocytes lysis, they were not able to induce cell death of human keratinocytes, as promoted by L. laeta venom, in the concentrations tested. These results indicate that other species of Loxosceles, in addition to those classified as medically important, have toxic potential to cause accidents in humans, despite interspecific variations that denote possible less toxicity.

Sphingomyelinase D activity in Sicarius Tropicus Venom: toxic potential and clues to the evolution of SMases D in the Sicariidae family

The spider family Sicariidae includes three genera, Hexophthalma, Sicarius and Loxosceles. The three genera share a common characteristic in their venoms: the presence of Sphingomyelinases D (SMase D). SMases D are considered the toxins that cause the main pathological effects of the Loxosceles venom, that is, those responsible for the development of loxoscelism. Some studies have shown that Sicarius spiders have less or undetectable SMase D activity in their venoms, when compared to Hexophthalma. In contrast, our group has shown that Sicarius ornatus, a Brazilian species, has active SMase D and toxic potential to envenomation. However, few species of Sicarius have been characterized for their toxic potential. In order to contribute to a better understanding about the toxicity of Sicarius venoms, the aim of this study was to characterize the toxic properties of male and female venoms from Sicarius tropicus and compare them with that from Loxosceles laeta, one of the most toxic Loxosceles venoms. We show here that S. tropicus venom presents active SMases D. However, regarding hemolysis development, it seems that these toxins in this species present different molecular mechanisms of action than that described for Loxosceles venoms, whereas it is similar to those present in bacteria containing SMase D. Besides, our results also suggest that, in addition to the interspecific differences, intraspecific variations in the venoms’ composition may play a role in the toxic potential of venoms from Sicarius species.

Searching for the toxic potential of Loxosceles amazonica and Loxosceles willianilsoni spiders’ venoms

The Loxosceles genus belongs to the Sicariidae family and it comprises species whose venom can cause accidents with potentially fatal consequences. We have previously shown that SMase D is the enzyme responsible for the main pathological effects of Loxosceles venom. Despite the severity of accidents with Loxosceles, few species are considered to be of medical importance. Little is known about the venom of non-synanthropic species that live in natural environments. To contribute to a better understanding about the venom's toxicity of Loxosceles genus, the aim of this study was to (i) characterize the toxic properties of Loxosceles amazonica from two different localities and a recent described cave species Loxosceles willianilsoni and (ii) compare these venoms with that from Loxosceles laeta, which is among the most toxic ones. We show here that both L. amazonica venoms (from the two studied locations) and L. willianilsoni presented SMase D activity similar to that exhibited by L. laeta venom. Although L. amazonica and L. willianilsoni venoms were able to induce complement dependent human erythrocytes lysis, they were not able to induce cell death of human keratinocytes, as promoted by L. laeta venom, in the concentrations tested. These results indicate that other species of Loxosceles, in addition to those classified as medically important, have toxic potential to cause accidents in humans, despite interspecific variations that denote possible less toxicity.

Description of the male of the critically endangered tarantula Typhochlaena curumim bertani, 2012 (Araneae, Theraphosidae), with comments on tarantula trade and conservation

The genus Typhochlaena C.L. Koch, 1850 consists of five small size arboreal tarantula species with remarkable colored abdominal patterns and a very restricted geographic range in Brazil. Here, we describe the male of Typhochlaena curumim Bertani, 2012, which was collected in an area of Brazilian Atlantic Rainforest. The new record extends the northern limit of the geographic range for both the genus and species. As Typhochlaena spp. are now especially popular and requested in the pet market, and because T. curumim is classified as Critically Endangered, we discuss the impacts of the international trade and other challenges on conservation of the genus.

Two new species of Guyruita Guadanucci et al., 2007 (Araneae, Theraphosidae) from Brazil.

Guyruita Guadanucci et al., 2007 is an ischnocoline genus with three described species from Brazil and Venezuela. Two new Brazilian species from the states of Rio Grande do Norte (Guyruita isae n. sp.) and Espírito Santo (Guyruita giupponii n. sp.) are described. A key is provided for identification of Guyruita species. Map with records and information on species habitat are also given.

Two new species of Guyruita Guadanucci et al., 2007 (Araneae, Theraphosidae) from Brazil

Guyruita Guadanucci et al., 2007 is an ischnocoline genus with three described species from Brazil and Venezuela. Two new Brazilian species from the states of Rio Grande do Norte (Guyruita isae n. sp.) and Espirito Santo (Guyruita giupponii n. sp.) are described. A key is provided for identification of Guyruita species. Map with records and information on species habitat are also given.

Spiders of the São Paulo state islands, Brazil: redescription of Stenoterommata rassimana (Mello-Leitão, 1923) n. comb. (Araneae, Nemesiidae).

Spiders of the islands on the coast of the state of São Paulo, Brazil are poorly known. Herein, we redescribe and discuss the taxonomic position of Psalistops crassimanus Mello-Leitão, 1923, described from Alcatrazes Island and formerly included in the Barychelidae. This species is, herein, transferred to the genus Stenoterommata Holmberg, 1881, Nemesiidae, and the new combination Stenoterommata crassimana (Mello-Leitão, 1923) n. comb. is established. Stenoterommata crassimana males are diagnosed by the very slender and long apical portion of embolus having a strong curvature close to its apex. The females have the spermathecae with single elongate lobe bearing two receptacles. This species is probably endemic to the Alcatrazes Archipelago and Queimada Grande and Queimada Pequena Islands, on the coast of the state of São Paulo, Brazil.

Two new Brazilian species of Loxosceles Heinecken & Lowe, 1832 with remarks on amazonica and rufescens groups (Araneae, Sicariidae).

The genus Loxosceles Heinecken & Lowe, 1832 has 91 representatives in the New World. Despite medical relevancy, the taxonomy of the genus is poorly understood. South American Loxosceles were divided into four groups of species: laeta, spadicea, gaucho and amazonica; this last one has a single species, Loxosceles amazonica Gertsch, 1967. More recently, the natural occurrence of L. amazonica in the New World has been questioned, due to the strong morphological resemblance and close phylogenetic relationship with Old World species, mainly with Loxosceles rufescens (Dufour, 1820). Herein, L. amazonica is rediagnosed and its morphological variation and natural distribution discussed. Two new species closely related to it from northeastern Brazil are also described, Loxosceles willianilsonisp. n., from the state of Rio Grande do Norte, and Loxosceles muriciensissp. n., from the state of Alagoas. The relationships of these new species with L. amazonica and L. rufescens are discussed.

Taxonomic revision and cladistic analysis of Avicularia Lamarck, 1818 (Araneae, Theraphosidae, Aviculariinae) with description of three new aviculariine genera.

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, Ybyraporagen. n., Caribenagen. n., and Antillenagen. 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 merianaesp. n., Avicularia lynnaesp. n., and Avicularia caeisp. 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: Caribenagen. n., composed of Caribena laeta (C. L. Koch, 1842), comb. n. and Caribena versicolor (Walckenaer, 1837), comb. n.; Antillenagen. n., with a single species, Antillena rickwesti (Bertani & Huff, 2013), comb. n., both from the Caribbean; and Ybyraporagen. 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 variegatastat. 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, Caribenagen. n., Ybyraporagen. n. and Antillenagen. n. species. Maps with records and information on species habitat are also presented. Lectotypes are newly designed for Avicularia avicularia, Avicularia variegatastat. n., Avicularia juruensis, Caribena laetacomb. n., Euathlus affiniscomb. n. and a neotype is established for Caribena versicolorcomb. n.

Vitalius nondescriptus comb. nov. (Araneae: Theraphosidae: Theraphosinae): an example of theraphosid taxonomic chaos

The male holotype of Hapalopus nondescriptus Mello-Leitão, 1926 is redescribed, illustrated and compared with freshly collected specimens from the type locality. The only difference noted among the holotype and the new material concerns the development of the subapical keel. Its taxonomic position is reinterpreted and discussed, resulting in its transfer to the genus Vitalius Lucas, Silva Junior & Bertani, 1993, and thus making the new combination Vitalius nondescriptus (Mello-Leitão, 1926) comb. nov. The female is described for the first time and the morphological variations in two males, born from the female used in the description, is presented and illustrated. The male differs from those of other Vitalius species by the palpal bulb with short apical keel and bifid tibial spur with narrow prolateral branch and almost straight retrolateral branch. The female differs from those of other Vitalius species by urticating hair of 'type I' having the region 'a' shorter than region 'b'. Hapalopus nondescriptus has a confusing taxonomic history, since the holotype specimen was also used to describe another theraphosid species (Cyclosternum melloleitaoi Bücherl, Thimoteo & Lucas, 1971) which was, consequently, considered its objective synonym. Thus, we consider it a clear example of theraphosid taxonomical chaos.

Metriura Drolshagen & Bäckstam, 2009 (Araneae: Dipluridae) is a junior synonym of Fufius Simon, 1888 (Araneae: Cyrtaucheniidae)

The monotypic diplurid Metriura Drolshagen & Bäckstam, 2009 is placed in synonymy with Fufius (Cyrtaucheniidae) syn. nov. since Metriura lacks two of three diplurid synapomorphies (elongate posterior lateral spinnerets and the widely separated posterior median spinnerets) and shares synapomorphies with both aporoptychine cyrtaucheniids (subquadrate maxilla and a longer than wider labium) and Fufius (recurved and broad fovea, the typical incrassate tibia I of the male, with the spur having a single short branch and an apical megaspine, the basally curved metatarsus I and provided with a ventral tubercle). The type species of Metriura, M. striatipes Drolshagen & Bäckstam, 2009 is considered valid, and due to the synonymy of Metriura with Fufius, Fufius striatipes (Drolshagen & Bäckstam, 2009) comb. nov. is established.

Metriura Drolshagen & Bäckstam, 2009 (Araneae: Dipluridae) is a junior synonym of Fufius Simon, 1888 (Araneae: Cyrtaucheniidae)

The monotypic diplurid Metriura Drolshagen & Bäckstam, 2009 is placed in synonymy with Fufius (Cyrtaucheniidae) syn. nov. since Metriura lacks two of three diplurid synapomorphies (elongate posterior lateral spinnerets and the widely separated posterior median spinnerets) and shares synapomorphies with both aporoptychine cyrtaucheniids (subquadrate maxilla and a longer than wider labium) and Fufius (recurved and broad fovea, the typical incrassate tibia I of the male, with the spur having a single short branch and an apical megaspine, the basally curved metatarsus I and provided with a ventral tubercle). The type species of Metriura, M. striatipes Drolshagen & Bäckstam, 2009 is considered valid, and due to the synonymy of Metriura with Fufius, Fufius striatipes (Drolshagen & Bäckstam, 2009) comb. nov. is established.

Vitalius nondescriptus comb. nov. (Araneae: Theraphosidae: Theraphosinae): an example of theraphosid taxonomic chaos

The male holotype of Hapalopus nondescriptus Mello-Leitão, 1926 is redescribed, illustrated and compared with freshly collected specimens from the type locality. The only difference noted among the holotype and the new material concerns the development of the subapical keel. Its taxonomic position is reinterpreted and discussed, resulting in its transfer to the genus Vitalius Lucas, Silva Junior & Bertani, 1993, and thus making the new combination Vitalius nondescriptus (Mello-Leitão, 1926) comb. nov. The female is described for the first time and the morphological variations in two males, born from the female used in the description, is presented and illustrated. The male differs from those of other Vitalius species by the palpal bulb with short apical keel and bifid tibial spur with narrow prolateral branch and almost straight retrolateral branch. The female differs from those of other Vitalius species by urticating hair of 'type I' having the region 'a' shorter than region 'b'. Hapalopus nondescriptus has a confusing taxonomic history, since the holotype specimen was also used to describe another theraphosid species (Cyclosternum melloleitaoi Bücherl, Thimoteo & Lucas, 1971) which was, consequently, considered its objective synonym. Thus, we consider it a clear example of theraphosid taxonomical chaos.

Metriura Drolshagen & Bäckstam, 2009 (Araneae: Dipluridae) is a junior synonym of Fufius Simon, 1888 (Araneae: Cyrtaucheniidae)

The monotypic diplurid Metriura Drolshagen & Bäckstam, 2009 is placed in synonymy with Fufius (Cyrtaucheniidae) syn. nov. since Metriura lacks two of three diplurid synapomorphies (elongate posterior lateral spinnerets and the widely separated posterior median spinnerets) and shares synapomorphies with both aporoptychine cyrtaucheniids (subquadrate maxilla and a longer than wider labium) and Fufius (recurved and broad fovea, the typical incrassate tibia I of the male, with the spur having a single short branch and an apical megaspine, the basally curved metatarsus I and provided with a ventral tubercle). The type species of Metriura, M. striatipes Drolshagen & Bäckstam, 2009 is considered valid, and due to the synonymy of Metriura with Fufius, Fufius striatipes (Drolshagen & Bäckstam, 2009) comb. nov. is established.

Vitalius nondescriptus comb. nov. (Araneae: Theraphosidae: Theraphosinae): an example of theraphosid taxonomic chaos

The male holotype of Hapalopus nondescriptus Mello-Leitão, 1926 is redescribed, illustrated and compared with freshly collected specimens from the type locality. The only difference noted among the holotype and the new material concerns the development of the subapical keel. Its taxonomic position is reinterpreted and discussed, resulting in its transfer to the genus Vitalius Lucas, Silva Junior & Bertani, 1993, and thus making the new combination Vitalius nondescriptus (Mello-Leitão, 1926) comb. nov. The female is described for the first time and the morphological variations in two males, born from the female used in the description, is presented and illustrated. The male differs from those of other Vitalius species by the palpal bulb with short apical keel and bifid tibial spur with narrow prolateral branch and almost straight retrolateral branch. The female differs from those of other Vitalius species by urticating hair of 'type I' having the region 'a' shorter than region 'b'. Hapalopus nondescriptus has a confusing taxonomic history, since the holotype specimen was also used to describe another theraphosid species (Cyclosternum melloleitaoi Bücherl, Thimoteo & Lucas, 1971) which was, consequently, considered its objective synonym. Thus, we consider it a clear example of theraphosid taxonomical chaos.

Revalidation of Pterinopelma Pocock 1901 with description of a newspecies and the female of Pterinopelma vitiosum (Keyserling 1891)(Araneae Theraphosidae Theraphosinae)

We revalidate the theraphosid genus Pterinopelma Pocock 1901, describe the female of P. vitiosum for first time and Pterinopelmasazimai sp. nov. from Brazil. These two species were included in a matrix with 35 characters and 32 taxa andwere analyzed both with all characters having same weight and with implied weights. Searches considering all charactersnon-additive or some additive were also carried out. The preferred tree, obtained with implied weights, concavity 6 andall characters non-additive shows that Pterinopelma is a monophyletic genus sister to the clade Lasiodora (Vitalius +Nhandu). The presence of denticles on the prolateral inferior male palpal bulb keel is a synapomorphy of the genus.

On the Avicularia (Araneae: Theraphosidae: Aviculariinae) species from Uruguay

The taxonomic status of four species of Avicularia Lamarck 1818 described from Uruguay: Aviculariaanthracina (C.L. Koch 1842), Avicularia alticeps (Keyserling 1878), Avicularia parva (Keyserling 1878) and Aviculariatigrina (Pocock 1903) is discussed. The holotypes and/or original descriptions of these species were examined, and twotaxonomic synonymies are needed, which are presented herein. Avicularia anthracina is transferred to Grammostola, resulting in Grammostola anthracina (C.L. Koch 1842) new combination and is considered a senior synonym of Grammostola mollicoma Ausserer 1875 new synonymy. Likewise, Avicularia parva is transferred to Catumiri Guadanucci 2004, where it is placed in the synonymy of Catumiri uruguayense Guadanucci 2004 new synonymy. Avicularia tigrina andAvicularia alticeps, originally described in the genera Ischnocolus Ausserer 1875 and Pterinopelma Pocock 1901,respectively, are herein considered nomina dubia since their types are presumed lost.

Metriura Drolshagen & Bäckstam, 2009 (Araneae: Dipluridae) is a juniorsynonym of Fufius Simon, 1888 (Araneae: Cyrtaucheniidae)

The monotypic diplurid Metriura Drolshagen & Bäckstam, 2009 is placed in synonymy with Fufiu(Cyrtaucheniidae) syn. nov. since Metriura lacks two of three diplurid synapomorphies (elongate posterior lateral spinnerets and the widely separated posterior median spinnerets) and shares synapomorphies with both aporoptychine cyrtaucheniids (subquadrate maxilla and a longer than wider labium) and Fufius (recurved and broad fovea, the typical incrassate tibia I of the male, with the spur having a single short branch and an apical megaspine, the basally curved metatarsus I and provided with a ventral tubercle). The type species of Metriura, M. striatipes Drolshagen & Bäckstam, 2009 is considered valid, and due to the synonymy of Metriura with Fufius, Fufius striatipes (Drolshagen & Bäckstam, 2009) comb. nov. is established.