Sicarius terrosus (six-eyed cave spider) is a highly toxic (and somewhat infamous) spider of the sicariidae family, whose bites, however rare, are characterised by significant necrotic pathology and potential mortality. This is largely because of the presence of sphingomyelinase D in its venom, in the form of Phospholipase D StSicTox-betaIC1. This has been shown to cause dermonecrosis in mammals as well as being a potent insecticide. Additionally an StSicTox-beta IF1 variant is present, which similarly catalyses sphingomyelin hydrolysis, does so with low effectiveness and does not cause dermonecrosis, blood vessel permeability and platelet aggregation. Two cytochrome C oxidase subunits (catalyses reduction of O2 to H2O) are found in this venom, as well as reserves of NADH dehydrogenase.