The venoms of the lesser (Echiichthys vipera) and greater (Trachinus draco) weever fish– A review

In comparison with other animal venoms, fish venoms remain relatively understudied. This is especially true for that of the lesser Echiichthys vipera and greater weever fish Trachinus draco which, apart from the isolation of their unique venom cytolysins, trachinine and dracotoxin, respectively, remain relatively uncharacterised. Envenomation reports mainly include mild symptoms consisting of nociception and inflammation. However, like most fish venoms, if the venom becomes systemic it causes cardiorespiratory and blood pressure changes. Although T. draco venom has not been studied since the 1990's, recent studies on E. vipera venom have discovered novel cytotoxic components on human cancer cells, but due to the scarcity of research on the molecular make-up of the venom, the molecule(s) causing this cytotoxicity remains unknown. This review analyses past studies on E. vipera and T. draco venom, the methods used in the , the venom constituents characterised, the reported symptoms of envenomation and compares these findings with those from other venomous Scorpaeniformes. •Research on the weever fish venoms Echiichthys vipera and Trachinus draco hasbeen scarce.•E. vipera and T. draco venoms elicit cardiorespiratory symptoms in victims.•E. vipera and T. draco contain unique cytolysins – Trachinine and Dracotoxin.•Dracotoxin is haemolytic and contains membrane depolarising activities.•E. vipera venom triggers apoptosis in human colon carcinoma cells.