ABSTRACT Although Brazil has one of the highest scorpion diversities worldwide, the scorpion fauna of the Amazon region remains relatively poorly described. In this study, we updated the list of scorpion species from the state of Acre, in the southwestern Brazilian Amazon, based on a revision of records contained in Brazilian arachnid collections and a survey of the relevant literature. We recorded the occurrence of seven scorpion species belonging to two families (Buthidae and Chactidae) among which we report three new records (Ananteris sp., Tityus (Tityus) gasci, and Chactopsis cf. insignis) for Acre. The results presented herein make an important contribution to the knowledge on scorpion diversity in the Amazonian forests of Acre.

RESUMEN Aunque Brasil tiene una de las diversidades de escorpiones más altas del mundo, la fauna de escorpiones de la región amazónica sigue siendo relativamente poco descrita. En este estudio, actualizamos la lista de especies de escorpiones para el estado de Acre, en el suroeste de la Amazonía brasileña, en base a una revisión de los registros contenidos en colecciones de arácnidos brasileños y un estudio de la literatura relevante. Registramos la ocurrencia de siete especies de escorpiones pertenecientes a dos familias (Buthidae y Chactidae), entre las cuales informamos tres nuevos registros (Ananteris sp., Tityus (Tityus) gasci y Chactopsis cf. insignis) para Acre. Los resultados presentados aquí hacen una contribución importante al conocimiento acerca de la diversidad de escorpiones en los bosques amazónicos de Acre.

ABSTRACT During a faunal rescue conducted at a hydroelectric power station constructed in a Cerrado savanna area in the state of Mato Grosso, a sample of five small stripe-patterned individuals of snakes of the genus Apostolepis Cope, 1862 document the existence of an undescribed species, which is named herein. The new species can be distinguished from its congeners by a combination of scale counts, number of maxillary teeth and color pattern. The new species is most similar to Apostolepis borellii Peracca, 1904, A. lineata Cope, 1887, A. nelsonjorgei Lema & Renner, 2004, A. nigroterminata Boulenger, 1896, A. serrana Lema & Renner, 2006 and A. underwoodi Lema & Campbell, 2017 in its coloration pattern. However, it is distinguished from these species by having a pair of triangular blotches covering portions of the third to sixth supralabials, a white nuchal collar, the shape of the fourth supralabial and the shape of the tip of tail, the number of supralabials in contact with parietals, the size of the anterior chinshields, the color pattern of the paraventral side, parietal and terminal scales, the width of dorsal stripes, and a distinct number of subcaudals. The new species occurs in areas within the Cerrado biome.