Venom-microbiomics of eight species of Neotropical spiders from the Theraphosidae family.

AIM: Tarantulas are one of the largest predatory arthropods in tropical regions. Tarantulas though not lethal to humans, their venomous bite kills small animals and insect upon which they prey. To understand the abiotic and biotic components involved in Neotropical tarantula bites, we conducted a venom-microbiomics study in eight species from Costa Rica. METHODS AND RESULTS: We determined that the toxin profiles of tarantula venom are highly diverse using shotgun proteomics; the most frequently encountered toxins were ω-Ap2 toxin, neprilysin-1, and several teraphotoxins. Through culture-independent and culture-dependent methods, we determined the microbiota present in the venom and excreta to evaluate the presence of pathogens that could contribute to primary infections in animals, including humans. The presence of opportunistic pathogens with hemolytic activity was observed, with a prominence of Stenotrophomonas in the venoms. Other bacteria found in venoms and excreta with hemolytic activity included members of the genera Serratia, Bacillus, Acinetobacter, Microbacterium, and Morganella. CONCLUSIONS: Our data shed light on the venom- and gut-microbiome associated with Neotropical tarantulas. This information may be useful for treating bites from these arthropods in both humans and farm animals, while also providing insight into the toxins and biodiversity of this little-explored microenvironment.

The scent gland chemistry of Gagrellinae (Opiliones, Sclerosomatidae): evidence for sequestration of myrmicacin in a species of Prionostemma.

The scent gland secretion of an undetermined species of Prionostemma from Costa Rica was analyzed by gas chromatography-mass spectrometry and shown to consist of medium-chain carboxylic acids (mainly octanoic acid) and a ß-hydroxy-carboxylic acid, eventually identified as myrmicacin (= (R)-3-hydroxydecanoic acid). While scent gland secretions in harvestmen have traditionally been considered to be products of de novo synthesis, we here provide evidence for the unusual case of sequestration-derived scent gland constituents: at least myrmicacin appears to be sequestered from leaf-cutter ants that constitute a part of the prey of the Prionostemma-species herein investigated. This is the first report on the scent gland chemistry of the sclerosomatid subfamily Gagrellinae as well as on a possible sequestration mechanism in harvestmen.

Aracnofauna (Arachnida) de la Isla del Coco, Costa Rica, con la descripción de tres nuevas especies

Introducción: Los arácnidos de la isla del Coco representan 50 especies, ubicadas en seis órdenes y 26 familias. El trabajo de actualización del conocimiento de la fauna de este grupo de animales en la isla inició no sistemáticamente hace más de 127 años, donde un escorpión se convirtió en el primer espécimen citado del grupo. Objetivo: Actualizar la lista de especies de arácnidos para la Isla del Coco, aportando nueva información sobre taxones poco conocidos y describiendo nuevas especies. Métodos: Durante dos expediciones, llevadas a cabo del 11 al 22 de abril 2013 y del 8 al 18 julio 2017, se recolectaron arácnidos con métodos manuales y trampas, se preservaron en etanol y se realizaron las identificaciones en laboratorio. Los rangos de distribución están basados en el catálogo de arañas del mundo, las identificaciones realizadas, se respaldan en la literatura específica citada para cada caso y las sugerencias biogeográficas presentadas de los grupos o especies tratadas, surgen del análisis de los patrones de distribución general que presenta el género o grupo citado. Resultados: Los hallazgos principales incluyen la adición de nuevos registros de especies para la isla, un orden, 11 familias y 29 especies, de las cuales tres son nuevas para la ciencia. Conclusiones: Es necesario continuar con el inventario de la aracnofauna de la isla, principalmente en los sectores que no han podido ser previamente muestreados. A nivel biogeográfico la fauna de arañas que habita la isla está mayormente relacionadas con Centroamérica, mientras que las especies de hábitos cosmopolitas posiblemente sean de reciente introducción.

Introduction: The arachnids of Isla del Coco represent 50 species, located in six orders and 26 families. The work of updating the knowledge of the fauna of this group of animals on the island began not systematically more than 127 years ago, where a scorpion became the first specimen cited in the group. Objective: To update the list of arachnid species for Coco Island, providing new information about little-known taxa and describing new species. Methods: During two expeditions, carried out from April 11 to 22, 2013 and from July 8 to 18, 2017, arachnids were collected with manual methods and traps, preserved in ethanol and identified in the laboratory. The distribution ranges are based on the spiders catalog of the world, the identifications made, are supported by the specific literature cited for each case and the biogeographical suggestions presented of the groups or species treated, arise from the analysis of the general distribution patterns that presents the genus or group cited. Results: The main findings include the addition of new species records for the island, one order, 11 families and 29 species, of which three are new to science. Conclusions: It is necessary to continue with the inventory of the island fauna, mainly in the sectors that could not be previously sampled. At the biogeographical level, the spider fauna that inhabits the island is mostly related to Central America, while the species with cosmopolitan habits are possibly of recent introduction.

[Complements to the description of Tityus dedoslargos (Scorpiones: Buthidae)]. / Complementos a la descripción de Tityus dedoslargos (Scorpiones: Buthidae).

The female of the Costarican scorpion Tityus dedoslargos Francke and Stockwell, 1987 is described for the first time and new data on its morphological variation and natural history are given. The female differs from the male mainly in having an enlarged basal median lamellae on the pectines, and lacking modified pedipalps. The species type locality relocated. This species is recorded from only two Costarican provinces: San Jose and Puntarenas.

[Centruroides Schmidti (scorpiones: Buthidae) in Costa Rica]. / Centruroides schmidti (Scorpiones: Buthidae) en Costa Rica.

Centruroides schmidti Sissom, 1995 is the new identification designate of the scorpions previously known as C. thorelli (Kraepelin, 1891) in Northwest Costa Rica. The geographical distribution of the species in this country is established on the basis of new collected material. Its distribution includes the Pacific slope of the Guanacaste volcanic range, and the Pacific and Atlantic slopes of the Tilarán volcanic range between 50 and 775 m elevation above sea level, within the Costa Rican Guanacaste and Alajuela provinces.

Centruroides schmidti (Scorpiones: Buthidae) en Costa Rica / Centruroides Schmidti (scorpiones: Buthidae) in Costa Rica

Centruroides schmidti Sissom, 1995 is the new identification designate of the scorpions previously known as C. thorelli (Kraepelin, 1891) in Northwest Costa Rica. The geographical distribution of the species in this country is established on the basis of new collected material. Its distribution includes the Pacific slope of the Guanacaste volcanic range, and the Pacific and Atlantic slopes of the Tilarßn volcanic range between 50 and 775 m elevation above sea level, within the Costa Rican Guanacaste and Alajuela provinces.

Complementos a la descripción de Tityus dedoslargos (Scorpiones: Buthidae) / Complements to the description of Tityus dedoslargos (Scorpiones: Buthidae)

The female of the Costarican scorpion Tityus dedoslargos Francke and Stockwell, 1987 is described for the first time and new data on its morphological variation and natural history are given. The female differs from the male mainly in having an enlarged basal median lamellae on the pectines, and lacking modified pedipalps. The species type locality relocated. This species is recorded from only two Costarican provinces: San Jose and Puntarenas.