You Don't Know Jacks! A Guide to Gulf of Mexico Seriola Jacks

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Fisheries, Marine Resources

Publications

Publication Number: P3852

View as PDF: P3852.pdf

You don’t know jacks—or do you? Below are some useful hints to help you correctly identify your fish.

Is it larger than 3 feet? If so, it’s a greater amberjack.
Is it deep-bodied with a tall dorsal fin? If so, it’s an almaco jack.

If not, the number of spines and position of the eyes will help you determine the species.

Click here for a more comprehensive and interactive identification guide.

Click here for up-to-date fishing regulations.

Species	Full Body	First Dorsal Fin Spine #	Maxilla-Eye Alignment	Key Characteristics
Banded rudderfish	Slender body May have a yellow stripe from mouth to tail Bony keel on tail Tips of tail are white Anal fin approximately half the length of second dorsal fin Silver-green in color	8	Maxilla extends past the center of the eye.	Bony keel by tail White-tipped tail Flat-edged mouth Maximum fork length: 2’3”
Lesser amberjack	Dark stripe from eye ends before first dorsal fin Anal fin approximately two-thirds the length of second dorsal fin Silver-brown in color	8	Maxilla extends to the front edge of the eye.	Blunt mouth Stripe not to first dorsal fin Proportionally larger eye Maximum fork length: 2’2”
Greater amberjack	Dark stripe from eye to middle of first dorsal fin Anal fin more than two-thirds the length of second dorsal fin Silver-brown in color	7	Maxilla extends to the center of the eye. Corner of maxilla is upturned.	Slender body Stripe to first dorsal fin Corner of mouth upturned Maximum fork length: 3’7”
Almaco jack	Deep body Dark stripe from eye to middle of first dorsal fin Beginning of second dorsal fin and anal fin elongated Anal fin nearly the length of second dorsal fin Bronze-gray in color	7	Maxilla extends past the front edge of the eye.	Deep body Tall dorsal and anal fins Maximum fork length: 2’7”

Click the PDF above for a visual guide.

Publication 3852 (02-23)

MASGP-22-038

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