Blue-fin Tuna Thunnus thynnus
One of the largest bony fish in the world, the northern bluefin tuna has a very streamlined and powerful body. It can reach up to 300 cm in length and weigh over 450 kg. It can sometimes be found off the eastern, southern and south-western coasts of the British Isles. Image: Tom Puchner (iNaturalist).
Find out more: iNaturalist, Marine Life Information Centre