Blue shark. Size: 6 to 9 feet long. ... Size: The largest of the thresher sharks, common threshers can reach lengths of up to 20 feet, though most of that length is its long tail fin.

They normally grow up to an average size of 230cm long, however in 2005 a Welsh record was set 25 miles off the coast of Milford Haven, when a fisherman hauled in a blue shark measuring a massive ...