''Sicarius tropicus'' is a species of six-eyed sand spider ('' Sicarius'') endemic in South American

caatinga Caatinga (, ) is a type of semi-arid tropical vegetation, and an ecoregion characterized by this vegetation in interior northeastern Brazil. The name "Caatinga" is a Tupi word meaning "white forest" or "white vegetation" (''caa'' = forest, v ...

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

. Like related spiders, it is venomous, but only one medically-significant bite has been recorded, causing dermonecrotic lesions in a 17-year-old boy.

Venom

A 2021 study compared the venom with that of ''

Loxosceles laeta The Chilean recluse spider, ''Loxosceles laeta'', is a highly venomous spider of the family Sicariidae. In Spanish, it (and other South American recluse spiders) is known as ', or "corner spider"; in Brazilian Portuguese, as ' or "brown spider". ...

'', considered the most toxic species in the genus. The venom of ''S. tropicus'' contains

Sphingomyelinase D Sphingomyelin phosphodiesterase D (EC 3.1.4.41, sphingomyelinase D) is an enzyme of the sphingomyelin phosphodiesterase family with systematic name sphingomyelin ceramide-phosphohydrolase. These enzymes catalyse the hydrolysis of sphingomyelin, res ...

, capable of causing dependent ''

hemolysis Hemolysis or haemolysis (), also known by several other names, is the rupturing ( lysis) of red blood cells (erythrocytes) and the release of their contents (cytoplasm) into surrounding fluid (e.g. blood plasma). Hemolysis may occur in vivo ...

''; the hemolysis mechanisms were found to differ between the two species.

References

{{Taxonbar, from=Q2401348 Sicariidae Spiders described in 1936 Spiders of Brazil