Sanguine frogfish in Los Cabos

How to recognize it

A globe-shaped, slightly compressed fish with rough skin covered in tiny spicules, a very large upturned mouth and limb-like pectoral fins with an 'elbow'. The first dorsal spine is a fishing pole about as long as the second spine, tipped with a tapering lure with thin filaments and a cluster of dark round swellings at its base. Color is yellow or yellow-brown to red, with brown spots and mottling; the belly has conspicuous brown spots, and there is sometimes a faint eyespot or dark round spot below the rear of the dorsal fin. The small round gill opening sits below and behind the base of the pectoral fin.

Biology

The sanguine frogfish lives only in the eastern Pacific, from the Gulf of California to Chile, including the Revillagigedo, Clipperton, Cocos, Malpelo and Galápagos islands. It lives on rocky bottoms from about 1 to 40 m, usually above 20 m, tucked into small recesses in the reef and especially along rock walls, where it blends in so well that it looks like an encrusting sponge.

Like all frogfishes it is an ambush hunter: it sits still, waits for small fish and crustaceans to come close and swallows them with its huge mouth. It can also change color to match its background, from yellow to orange, red, violet or brown. It lays eggs, and its biology in the wild is poorly studied.

Seeing them from the boat

The sanguine frogfish is a fish for divers and snorkelers, not anglers. Around Los Cabos it sits motionless in holes and on rock walls, so most people swim right past it. Search slowly along ledges and sponge-covered rock and look for an eye or the outline of a mouth.

It is not a sport fish and is almost never hooked. Local records from Los Cabos include specimens brought in by commercial fishermen and one coughed up by a larger fish caught in the area. If you ever find one on a line, put it back. Sport fishing is not allowed inside Cabo Pulmo National Park.

Rules & conservation

A dive and snorkel fish. If one is ever hooked, release it.

Don't confuse it with

The bandtail frogfish (Antennatus strigatus), also found around Cabo, has no big brown spots on the belly; it is yellowish to pinkish red with dark marbling, and its third dorsal spine forms a fixed hump bound down by skin. The scarlet frogfish (Abantennarius coccineus) has a speckled belly without large dark spots. The stone scorpionfish (Scorpaena mystes) is also mottled and sits still on the reef, but it has a normal fish shape with a bony, spiny head and venomous fin spines, and no lure.

Questions

By Max VargasTop Anglers, Cabo San Lucas · international judge at big game fishing world championships · reviewed October 2026

Sources

• Smithsonian Shorefishes of the Eastern Pacific: Abantennarius sanguineus
• FishBase: Abantennarius sanguineus
• FishBase: common names of Abantennarius sanguineus
• Eschmeyer's Catalog of Fishes: Antennarius sanguineus
• Eschmeyer's Catalog of Fishes: Antennarius strigatus
• WoRMS: Abantennarius sanguineus
• The ETYFish Project: Lophiiformes
• REEF 2002 winter print: sanguine frogfish
• mexican-fish.com: sanguine frogfish
• Smithsonian Shorefishes of the Eastern Pacific: bandtail frogfish
• Smithsonian Shorefishes of the Eastern Pacific: scarlet frogfish
• Smithsonian Shorefishes of the Eastern Pacific: stone scorpionfish
• NOM-059-SEMARNAT-2010, 2019 annex (DOF)

Top illustration: Top Anglers. Photos: iNaturalist contributors, credited on each photo.