Calcium-channel-blocker
Guides
Plectreurys tristis
primitive hunting spider
Plectreurys tristis is a large venomous spider in the family Plectreuridae, found in arid and semi-arid regions of western North America, Central America, and Mexico. Adult males reach approximately 12 mm in body length (25 mm with legs extended), with females larger in all proportions. The species produces a venom containing plectoxins, insecticidal peptides that specifically target N-type calcium channels. It constructs webs under rocks and debris, with females and immatures remaining in webs while adult males wander nocturnally.