This video says about itself:
16 September 2016
While most fish are completely harmless to people, there are some species that are mildly to extremely venomous and can actually kill humans. Jonathan travels the world to meet some of the most venomous fish in the sea.
Venomous fish have evolved many ways to inflict pain. There may be compounds in fish venoms that have medicinal uses. By Amber Dance, 11:30am, April 19, 2017: here.