COMMON MARINE FISHES 



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Figure 34 



YELLOWFIN TUNA 

 Neothunnus macropferus 



Relationship: A member of the tuna family, Thunnidae, together with the 

 albacore and the hluefin tuna.* 



Distinguishing Characters: The finlets, usually eight, following both the 

 second dorsal and anal fins ; the pectoral fin which reaches normally beyond the front 

 of the second dorsal fin, but not beyond the front of the anal fin ; the oval or tear- 

 shaped vent ; the back and lower edges of the preopercle meeting at an angle ; the 

 unmarked ventral liver surface of uniform color. Reaches a weight of 450 pounds 

 though California specimens rarely exceed 125 pounds. In both the albacore and the 

 bluefin tuna, the vent is round, and the ventral surface of the liver is radially striated. 

 Color: Metallic dark blue above, shading into silvery gray below. When first caught, 

 there is generally a golden yellow, irridescent band along the side. Fins tinged with 

 yellow ; the finlets usually lemon yellow edged with black. Belly marked with trans- 

 verse white bars with irregular white dots or blotches between, especially in younger 

 fish. 



Distribution: In the eastern Pacific, from Pt. Conception south to Peru; spans 

 the Pacific to Hawaii and Japan. Occurs in schools. 



Fishing Season: Taken throughout the year with heaviest landings usually in 

 the summer and fall. Almost all commercial fishing occurs south of the Mexican border. 

 Found off Southern California during the summer and fall. 



Importance: Second in poundage and first in value among California's fisheries 

 in 1946. Most of the catch is delivered at San Diego, the balance at Los Angeles. Used 

 almost entirely for canning. One of the most desirable game fish, in Southern California. 



Fishing Gear: Hook aud line with live bait; feather jigs; purse seines. Sport, 

 with live bait or trolling. 



* Tlie big-eye tuna, Parathunnus mebachi, occasionally enters the catch and may be confused with the yellow- 

 fin. It has, however, faint marginal striations on the ventral surface of the liver and a more enlongated pectoral flu. 



