Almaco Jack
Almaco Jack (Seriola rivoliana) is a saltwater species. The first thing to check: a tall, sickle-shaped front lobe on the soft dorsal fin, distinctly higher than an amberjack's. The look-alike to rule out is Greater Amberjack: amberjack are longer and more slender with a much lower front dorsal lobe; the almaco's tall sickle fin is the giveaway.
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| Scientific name | Seriola rivoliana |
|---|---|
| Also called | almaco, silver rudderfish, kahala |
| Water | Saltwater |
| Group | Jack |
| Temperature | Common between 68 and 82 °F. |
How to identify an Almaco Jack
- A tall, sickle-shaped front lobe on the soft dorsal fin, distinctly higher than an amberjack's.
- A noticeably deeper, more compressed body than a greater amberjack of the same length.
- A dark olive-brown bar running from the upper jaw through the eye, on a brassy body with a faint amber stripe.
If you would rather not work through a key on a wet deck, photograph the fish and let the app name it — you get the common and the scientific name back, and the record is filed before you release.
Fish it is mistaken for
| Species | How to tell them apart |
|---|---|
| Greater Amberjack | Amberjack are longer and more slender with a much lower front dorsal lobe; the almaco's tall sickle fin is the giveaway. |
| Yellowtail Kingfish | Yellowtail have a bright yellow tail and a brassy stripe running the length of the flank, with a low dorsal lobe. |
Side-by-side comparisons
Read the full entry for Greater Amberjack and Yellowtail Kingfish.
Where it lives
Deeper offshore structure in the Atlantic, Gulf and Pacific — wrecks, rigs, pinnacles and drop-offs, usually deeper than greater amberjack on the same grounds.
Temperature
Common between 68 and 82 °F.
The conditions that matter
Almaco hold over deep high-relief structure and come up on current, so the running tide over a rig or pinnacle is what turns them on. Because limits are frequently shared with or distinguished from greater amberjack, the dorsal lobe is worth a look before the fish is boxed.
Global Fishing League records 18 weather and water readings against every catch automatically — tide stage, barometric pressure, water temperature, salinity, dissolved oxygen, chlorophyll, swell, current, moon phase and more, taken at your GPS position at the moment you log the fish. Over a season that turns a hunch about almaco jack into a pattern you can read.
See every reading recorded with a catch, or the guides to what each reading means.
Size limits, bag limits and seasons
Size limits, bag limits, slot limits and seasons are set by your state wildlife agency — and for many offshore and migratory species by federal regulators — and on many waters they differ from the statewide rule. They also change between seasons. Check the current regulations for the exact water you are fishing before you keep a fish — we do not republish limits here, because a number that is a season out of date is worse than no number.
What the app does do is make your side of it accurate: every catch carries a length measured from the photograph, a GPS position and a timestamp, exportable if you ever need to show your work for a tournament or a record claim. It is also what a Global Fishing League entry is built from — a record that verifies itself, without publishing where you caught the fish.