European eel
Pike, C.; Crook, V.; Gollock, M. (2020). "Anguilla anguilla". IUCN Red List of Threatened Species. 2020: e.T60344A152845178. doi:10.2305/IUCN.UK.2020-2.RLTS.T60344A152845178.en. Retrieved 19 November 2021.