The Natterin proteins were first revealed in the venom of the medically significant Brazilian toadfish Thalassophryne nattereri (VTn) in five orthologs named Natterin (1–4, and -P). They were identified as being responsible for the main toxic non-lethal effects of the VTn, such as local edema and excruciating pain, that evolved to necrosis. Following the first identification, the group of Natterin-like proteins has been expanded over time. Several sequences homologous to Natterin have been identified in different teleostean genomes, such as the venomous catfish Plotosus lineatus and non-venomous fish, including lampreys-Lampetra japonica or Lethenteron camtschaticum and Lampetra morii, arctic charr Salvelinus alpinus, zebrafish Danio rerio, atlantic cod Gadus morhua, and ovate pompano Trachinotus ovatus.