Offshore & Bluewater

How to tell them apart

One identification cue for each species, from its profile. Open a profile for the full description, size and range.

Mahi-Mahi

The most distinctive sexual difference is the head: mature males ("bulls") develop a tall, blunt, vertical forehead, while females ("cows") have a smooth, rounded head.

King Mackerel

Two key features separate them: the lateral line of a king mackerel takes a distinct sharp dip beneath the second dorsal fin, and the front portion of the first dorsal fin is pale or uniform in color.

Spanish Mackerel

Two features cleanly separate Spanish from juvenile king mackerel: the front portion of the first dorsal fin is jet black, and the lateral line slopes gently and evenly toward the tail rather than dipping sharply.

Bar Jack

Slender and silvery, it is best told apart by the dark blue-black bar that runs the length of the back and drops into the lower lobe of the tail - a mark no other Atlantic jack shares.

Horse-Eye Jack

Look for a silvery, blue-gray to olive body, a deeply forked tail that is often dusky to yellowish, and a distinctly large eye.

Rainbow Runner

Look for a slender, cigar-shaped body and a deeply forked tail. The back is dark blue-green fading to a white belly, marked by two narrow electric-blue stripes with a broader olive-yellow band running between them along each flank.

Cobia

Cobia have a long, broad, somewhat flattened body that is dark chocolate-brown on the back fading to a paler belly, usually with a darker lateral stripe running from the snout through the eye to the tail.

Yellowfin Tuna

Yellowfin tuna are built for speed: a torpedo-shaped, metallic dark-blue body fading to silver-white below, with a band of yellow along the flank.

Wahoo

Wahoo can superficially resemble king mackerel, but the bold vertical stripes, more pointed snout, and elongated dorsal set them apart immediately.

Greater Amberjack

The most reliable identifying feature is a dark, diagonal "amberjack bar" or mask that runs from the mouth up through the eye to the front of the dorsal fin, more pronounced when the fish is excited or feeding.

Crevalle Jack

Two reliable field marks separate the crevalle from other jacks: a prominent round black spot on the gill cover (operculum) and a dark blotch at the base of each pectoral fin.

Great Barracuda

Great barracuda are unmistakable: long, slender, and torpedo-shaped, with a pointed head, a large jutting lower jaw, and a mouth full of formidable, dagger-like teeth designed for slashing prey in half.

False Albacore

A cluster of several dark spots is usually visible below the pectoral fin, between the pectoral and pelvic fins, which helps separate them from the similar Atlantic bonito.

California Yellowtail

California yellowtail are streamlined, torpedo-shaped fish built for speed, with a long body, a deeply forked tail, and the powerful musculature typical of the jack and amberjack family.

Atlantic Bonito

The Atlantic bonito is a compact, torpedo-shaped fish with the classic tuna-family look. Its steel-blue to greenish back carries dark, slanting stripes running diagonally onto the upper sides, fading to bright silvery flanks and belly.

Sailfish

Sailfish are unmistakable. The towering, sail-like first dorsal fin - often taller than the body is deep - is the signature feature, cobalt blue and spotted, folding down into a groove when the fish is cruising and flaring up during feeding or fighting.

Blackfin Tuna

The finlets running from the second dorsal and anal fins to the tail are dusky gray with at most a faint yellow wash - a key detail that separates blackfin from yellowfin tuna, whose finlets are bright yellow with a black edge.

Atlantic Mackerel

Atlantic mackerel are unmistakable once you have seen one. The body is slender and torpedo-shaped, iridescent blue-green on the back marked with a series of dark, wavy vertical bars, and bright silvery-white below.

Atlantic Bluefin Tuna

Bluefin are torpedo-shaped, metallic blue-black above and silver below, with short pectoral fins and a row of yellow finlets before the tail.

Albacore Tuna

Albacore are metallic dark-blue above and silver below with unmistakably long, sabre-like pectoral fins that reach past the anal fin - the surest way to tell them from other tunas.

Skipjack Tuna

Skipjack are streamlined and steel-blue above with silver sides marked by several bold dark horizontal stripes low on the belly - the surest ID among small tunas.

Blue Marlin

Blue marlin are cobalt-blue above and silvery-white below, with a spear-like bill, a high pointed dorsal fin, and pale vertical bars that flash when lit up.

Swordfish

Swordfish have a stout, scaleless body, a large eye, a tall stiff dorsal fin, and a long flat "sword" bill - broader and flatter than a marlin's round spear.

White Marlin

White marlin are lighter blue-green above with a rounded dorsal fin tip, rounded pectoral and anal fin tips, and often spotted fins, distinguishing them from the pointed-finned blue marlin.

Striped Marlin

Striped marlin are slate-blue above with silver sides marked by rows of pale blue vertical bars that glow when the fish lights up, a tall pointed dorsal fin, and a slender body.

Bigeye Tuna

Bigeye tuna have, as the name says, notably large eyes, a deep robust body, metallic dark-blue back and silver sides, and long pectoral fins.

Pacific Bonito

The oblique back stripes distinguish them from tunas and mackerel.

Almaco Jack

Almaco jacks are dusky, with faint amber or olive stripes down the sides, a dark upper body and a lighter belly that can look brassy or lavender, and a dark bar running back from the eye.

Roosterfish

Roosterfish are silvery with two dark curved bands sweeping down the body and a spectacular set of seven long, thread-like dorsal spines that fold down or rise like a rooster's comb.

African Pompano

African pompano are deep, flat and brilliantly silver, metallic blue to blue-green above, with a steep, blunt, curved head.

Cero Mackerel

The solid lateral stripe with spots separates them from the spotted Spanish mackerel and the plain-sided king mackerel.