Yellowfin and Bigeye tuna
Follow the key for identification shown by the numbers !
①Pectoral fin shape and length
Good for identification of;
-
Small size (under FL40cm) △
-
Medium size (FL45cm to FL120cm) 〇
-
Lage size (over FL120cm) ×
Pectoral fin is as long as the base of 2nd dorsal fin= Yellowfin tuna
Pectoral fin extends the base of 2nd dorsal fin= Bigeye tuna
Edge of the Pectoral fin is rather rounded= Yellowfin tuna
Edge of the Pectoral fin is rather sharpe= Bigeye tuna
Notes;
Best indicator as a first step, however individual difference exists.
②Caudal fin
Good for identification of;
-
Small size (under FL40cm) △
-
Medium size (FL45cm to FL120cm) 〇
-
Lage size (over FL120cm） 〇
Distinct notch observed = Yellowfin tuna
Notch like shape is rather smooth = Bigeye tuna
Notes;
Good indicator, however caudal fin could be easy damaged during the fishing process or condition of preservation. Also it has some individual differences.
③Pattern (belly)
Good for identification of;
-
Small size (under FL40cm) 〇
-
Medium size (FL45cm to FL120cm) 〇
-
Lage size (over FL120cm） ×
Regular pattern (unbroken stripes with regular spots) = Yellowfin tuna
Irregular pattern (broken stripes with random spots)= Bigeye tuna
Notes;
Good indicator, however pattern can become unclear depending to the condition of preservation.
④Liver (needs dissecting)
Good for identification of;
-
Small size (under FL40cm) 〇
-
Medium size (FL45cm to FL120cm) 〇
-
Lage size (over FL120cm） 〇
One part of the liver extends and pointed, with no clear lines = Yellowfin tuna
Liver is separated in approximately same size, with clear lines around the edge = Bigeye tuna
Notes;
Perfect indicator for all sizes, however needs dissecting.
