Specific arthropod (crab and insect) toxin that inhibits inactivation of voltage-gated sodium channels. It competes well with the site-3 toxin LqhalphaIT (from the scorpion L.quinquestriatus (AC P17728)) on binding to cockroach neuronal membranes (Ki=21.4 nM), and inhibits the inactivation of D.melanogaster channel (DmNav1), but not that of mammalian Navs expressed in Xenopus oocytes. Its activity is synergically enhanced by ligands of receptor site-4 (Bj-xtrIT (AC P56637)). Its ability to inhibit the channel mutant DmNav1[D1701R] only decreases 5-fold, whereas the inhibition activity is completely lost by LqhalphaIT and Av2 when tested on DmNav1[D1701R]. PD(50) is 1.15 pmol/100 mg (native toxin) or PD(50) is 2.65 pmol/100 mg (recombinant toxin) when injected inter-segmentally into blowfly larvae (S.falculata). Is inactive on mammals, when tested by subcutaneous injection into mice at a high dose (up to 5940 nmol/kg of mouse). Does not inhibit rNav1.2/SCN2A, rNav1.4/SCN4A, hNav1.5/SCN5A and rNav1.6/SCN8A. Belongs to the sea anemone short toxin (type III) family. Opinions are divided on whether Anemonia viridis (Forsskal, 1775) and Anemonia sulcata (Pennant, 1777) are separate species. Authors from PubMed:17492942 and PubMed:19609479 consider they are only one species, it is why their studies (on A.viridis) are integrated in this entry on A.sulcata.