Two new arthropod toxins purified from the venom of the Mexican scorpion Centruroides nigrescens

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  Two new arthropod toxins purified from the venom of the Mexican scorpion Centruroides nigrescens Abstract The venom of the slender black scorpion Centruroides nigrescens , from the State of Guerrero México, was fractionated by Sephadex G–50 gel filtration, followed by carboxymethyl cellulose ion separation and high–performance liquid chromatography, permitting to obtain two new peptides toxic to arthropods. The estimate LD 50 of the soluble venom for the insect Acheta domesticus was 11.1 μg/g body weight, and for the arthropod Armadillidium vulgare was 61.1 μg body weight . The amino acid sequence of toxin Cnige1 (toxic to A. domesticus and A. vulgare ) contains 65 amino acids, with a molecular mass of 7273.37 mass units, whereas toxin Cnige2, toxic to A. domesticus , contains 68 amino acids, with a molecular mass of 7548.81 units. Both peptides are well packed, containing 8 cysteines, which in the native venoms are forming 4 disulfide bridges each. The amino acid sequences f...

Two new species of Vitalius (Araneae: Theraphosidae) from the restingas of the states of Rio de Janeiro, Bahia and Sergipe, Brazil

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Two new species of Vitalius (Araneae: Theraphosidae) from the restingas of the states of Rio de Janeiro, Bahia and Sergipe, Brazil

ABSTRACT

Brazil is the country with the most diverse tarantula (Theraphosidae) fauna, having 215 described species. Vitalius Lucas, Silva Júnior & Bertani, 1993 is one of the most diverse and common genera in Southern, Southeastern and Central-West regions of Brazil with ten described species. Individuals of Vitalius species are large and widespread in areas of the Brazilian Atlantic Forest. A single species is known to occur in areas of Cerrado vegetation. Herein, two new species are described from areas of restinga, coastal areas typically with low vegetation and sandy soil, in the coast of the states of Rio de Janeiro (Vitalius restinga sp. nov.), Bahia and Sergipe (Vitalius sapiranga sp. nov.). Males and females of these two new species have a much longer than wide sternum. Males have a short apical keel in the male palpal bulb. The two species can be distinguished by embolus width, slender in V. restinga sp. nov. and thicker in V. sapiranga sp. nov. Females can be distinguished by the spermathecae shape, slender in V. restinga sp. nov. and broader in V. sapiranga sp. nov. These are the first known theraphosids endemic to Brazilian Atlantic Coast restingas. Biological data indicate V. sapiranga sp. nov. and maybe V. restinga sp. nov. commonly use bromeliads as retreats. It is herein hypothesized they are sister species occupying similar habitats in Brazilian coast, but separated by ca. 1,000 kilometers.

Bertani, R.. (2023). Two new species of Vitalius (Araneae: Theraphosidae) from the restingas of the states of Rio de Janeiro, Bahia and Sergipe, Brazil. Zoologia (curitiba), 40, e23001. https://doi.org/10.1590/S1984-4689.v40.e23001