Neurotoxin (PubMed:29424690). In vivo, induces pronounced contraction and tail twitching on zebrafish larvae, as well as death 5 hours later (PubMed:29424690). Nematocytes (PubMed:23151943, PubMed:29424690). In late planulae, transcripts are found throughout the ectoderm in nematocytes, with high concentration of expressing cells in the oral pole (PubMed:29424690). In primary polyps, is expressed in nematocytes in the body wall and physa ectoderm and in the upper and lower pharynx (PubMed:29424690). Higly expressed in late planulae, primary polyps, and both adult males and females (at protein level) (PubMed:31134275). Consistant with protein expression, transcripts are moderately expressed in gastrulae and highly expressed in early and late planulae, metamorphosing planulae, primary and juvenile polyps, and both adult males and females (PubMed:29424690, PubMed:31134275). Low expression in unfertilized eggs and blastulae (PubMed:31134275). Belongs to the NEP3 family. The exact range of the peptide is deduced from experimental results. It as been shown that the mature peptide weight is 10 kDa and is only composed of the first ShKT domain.