Northern Blue-Fin Tuna

Fact File: Common Name(s): Northern Blue-Fin Tuna or Tunny Scientific Name: Thunnus thynnus  (Linnaeus, 1758) Usual Size:Over 300cm - although usual to 200cm UK Record Weights from rod/line: Shore:Vacant Boat:851lb MAFF Minimum Size: Shore: Boat:

Identification: Largest of all the tuna species. Swim bladder present. Typical tunny shape and deep set from the middle of the first dorsal. Colour: Lower sides and belly silvery white with colourless transverse lines alternated with rows of colourless dots (these are more prevalent in adult fish and only visible on fresh fish - they dissipate on death). First dorsal fin yellow or bluish, second reddish-brown, anal fin and finlets dusky yellow and black edging. The keel is black in adult fish. Pectoral fin doesn't extend beyond the first dorsal. Breeding: Egg dispersal. Females attain maturing at the age of 4 to 5 years and this equates to a weight of between 270 to 300kg and may produce upwards of 10 million eggs per season Habitat: These are the most water tolerant of all the tuna species, and will tolerate waters of between 10/250C, and they are not known to migrate into a water mass of below 100C. Mainly an offshore species, although in the times of their fast feeding migrations are known to come occasionally inshore. Food: Small schooling fishes and squids, although they have an ability to eat crabs, and are known to be partial to Salmon, though mainly feeds on Herring, Scad and Mackerel. Range: In the Eastern Atlantic from The British Isles and North Sea down south to Canary Islands. Additional Notes: Historically known in the North Sea and still migrates around Western Ireland to Northern waters. Can exceed 1200lbs. REFERENCES: FAO Species Catalogue 2 - Scombrids of The World - Collette/Nauen Fishes of the North-Eastern Atlantic and the Mediterranean - Whitehead, Bauchot, Hureau, Nielsen, Tortonese Key to the Fishes of Northern Europe - Wheeler

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