Two fish anglers routinely mix up. Here is what actually separates them — and when and where you are likely to meet each.

Typical: 30–45 in, 15–40 lb
Quickest tell: The dark diagonal eye-bar (nuchal bar) running up to the first dorsal, plus the amber flank stripe, identifies greater amberjack; cobia is flatter-headed with a dark side stripe and a row of separate dorsal spines.

Typical: 30–45 in, 15–40 lb
Key field mark: A brown lateral stripe on a flat-headed, remora-like body with low isolated dorsal spines identifies cobia (often mistaken at a glance for a shark, which has gill slits and rough denticle skin).
Both run in Gulf of Mexico, South Florida & the Keys — that is where telling them apart actually matters.