Tuna (Thunnus) is a genus of large predatory fish which are located in all tropical, subtropical and temperate seas. They are among the most important edible fish and are of considerable importance to the fishing industry. We essentially distinguish between 8 species: albacore tuna, southern bluefin tuna, North Pacific bluefin tuna, bluefin tuna, yellowfin tuna, blackfin tuna, bigeye tuna and longtail tuna. Skipjack tuna (Katsuwonus pelamis) is the economically most important species of tuna and the only species of the genus Katsuwonus within the family of mackerels and tunas (Scombridae). It can grow to about one metre in length and reaches a weight of over 20 kg. The seven dark longitudinal stripes on the silvery belly side are typical for this fish.