AMBERJACK IDENTIFICATION

[REEFMAN]

.  SERIOLA RIVOLIANA
Longfin Amberjack aka Tropical Yellowtail (kzn); Almaco Jack (Australia); Longfin Yellowtail.

Much more common species than Dumerili in SA waters.
Attains up to 30kg, (60kg claims have been recorded internationally).
Most catches in SA are in the 15-25kg range.
 
     

• Maxilla reaches to the anterior margin of the eye.   
• Dorsal and Anal fins are longer than Dumerili.   
• Pectoral fin length is 1/2 to 3/4 the Dorsal fin height.   
• Olive-brown to blue-green above and a paler shade to brassy and white below. Younger specimens have white underside, which darkens with age.   
• Dark Bar crossing the eye to the Dorsal fin is clear in younger specimens. As the fish gets older, the dark line tends to fade.   
• Amber Midstripe varies greatly in intensity - tending to become more yellow as the fish ages.

NB: Was thought not to occur in the Atlantic, however this is probably not correct owing to numerous catches off Angola - original distribution probably mistaken as a misidentification of the Greater Amberjack (S Dumerili).
Distribution is probably circumtropical.



SERIOLA DUMERILI
Greater Amberjack

Found Indo-central Pacific, Persian Gulf to Algoa Bay and also in the Atlantic.
More abundant in Sub-tropical climates.
   

• Maxilla reaches to below the midpoint of the eye.   
• Bar crossing the eye to the Dorsal fin is dull. The younger fish sometimes have a dark stripe going through the eye. As the fish gets older, the dark line fades to a mere shadow.   
• Blue-grey to green in colour, silvery white below.   
• Distinct amber stripe along the middle of the body, which can vary greatly in intensity.   
• Dorsal and Anal fins are short.   
• Pectoral fin length EQUALS the Dorsal fin height.
  
  Not as common in SA waters as S. Rivoliana (Longfin Amberjack).
  Grows to bigger size than Longfin and can attain 100kg. 

Acknowledgements and References:

Dr Bruce Mann (ORI)
SKIBOAT Magazine (Jan 2009)
Coastal Fishes SA - Heemstra
Smith's Sea Fishes Encyclopedia

 
The Identification of these fish is not definitive and even using the above characteristics can still be difficult. This article is designed to just help out!

Good luck.
 

 
S. Rivoliana - Longfin Amberjack
Showing the vast differences in colouration in different aged specimens.

Thanks to the Rapsons!
 

 
 
More Longfins.... thanks to Wesley.
Note the older fish:
 
     

• becoming darker   
• the eye stripe fading   
• the amber stripe intensifying

 
 
 
 
 
GREATER AMBERJACK


 
Dr Bruce Mann published this finding in the SKIBOAT Magazine in January 2009


 
 
Finally, the other common Seriola species:

SERIOLA LALANDI
Cape Yellowtail; Southern Yellowtail (Aus); Yellowtail Kingfish (NZ)