Apomastus schlingeri

Apomastus schlingeri (misnomer Aptostichus schlingeri) is a species of venomous spiders belonging to a family of trapdoor spiders. They produce a complex of neurotoxins called aptotoxins. Both known species of the genus are found in the United States.

Venom
Apomastus schlingeri have a venom that is highly neurotoxic in effect. The neurotoxin is actually a complex of proteins called aptotoxins (Aps for short), which in turn belong to a group of neurotoxins called cyrtautoxins. There are at least nine different peptides, and most of them are directly paralytic and lethal to insect larvae. All of the peptides are voltage-gated sodium channel blockers. To date, Aps III is known to be the most potent peptide of all.