Sanguine Frogfish

Sanguine Frogfish, Antennatus sanguineus

The Sanguine Frogfish, Antennatus sanguineus, whose common Spanish name is ranisapo sangrón, is a species in the Frogfish or Antennariidae Family, known collectively as ranisapos in Mexico. This is one of the more exotic and most unusual fishes in the world and the most common Frogfish in the Tropical Eastern Pacific. Globally, there are twenty-four species in the genus Antennatus, nine of which are found in Mexican waters, five in the Atlantic and four in the Pacific.

The Sanguine Frogfish have globose, slightly compressed bodies with a large oblique mouth featuring numerous small villiform teeth. They are highly variable in color, being found in various shades of yellowish brown to red with brown spotting and mottling. They have conspicuous brown spots on their belly. Some have a weak ocellus round spot below the rear of their dorsal fin. Their eyes are on the sides of their head. They have small gill openings found behind and below the pectoral fin base. Their first dorsal spine (the “illicium”) is large and free, forming a movable “fishing rod” that is approximately equal in length to the second dorsal spine. The enticement lure (the “esca”) is an elongated tapering appendage with slender filaments and a cluster of darkly pigmented round swellings at the base. The second dorsal spine is also free; it is strongly curved and not attached to the head by a membrane. The third dorsal spine is movable and not bound by skin. They have large pectoral fins that are elongated and “leg-like” with an “elbow” joint and their pelvic fins are short. Their body is covered with rough skin.

The Sanguine Frogfish are a sedentary species found over rocky bottoms from the intertidal zone at depths up to 130 feet. They reach a maximum length of 13 cm (5.1 inches). They are voracious carnivores that sit quietly waiting for small fish to pass by. They also stalk fish and crustaceans. Reproduction occurs via pelagic eggs whereby a single female can release up to 300,000 eggs which form a buoyant “raft” that remains afloat for several days until hatching.

In Mexican waters the Sanguine Frogfish are found in all waters of the Pacific with the exception that that they are absent from the entire the west coast of Baja and the northern 20% of the Sea of Cortez. The collection photographed below documents a 40-mile northerly range extension into the Pacific along the extreme southwestern coast of Baja.

The Sanguine Frogfish is an easy fish to identify and cannot be confused with any other species due to the brown spots on its belly which are not present on any other Frogfish.

The Sanguine Frogfish is of limited value being used in the aquarium trade at modest level.

Sanguine Frogfish, Antennarius sanguineus. Fish provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, September 2011. Length: 8.3 cm (3.25 inches).