Roughjaw Frogfish, Fowlerichthys avalonis

Roughjaw Frogfish, Fowlerichthys avalonis. Fish caught from coastal waters off Mazatlán, Sinaloa, April 2018. Length: 15 cm (6.0 inches). Catch, photograph and identification courtesy of George Brinkman, Guelph, Ontario, Canada.

Roughjaw Frogfish, Fowlerichthys avalonis. Fish caught from coastal waters off Mazatlán, Sinaloa, April 2018. Length: 18 cm (7.0 inches). Catch, photograph and identification courtesy of George Brinkman, Guelph, Ontario, Canada.

Roughjaw Frogfish, Fowlerichthys avalonis. Fish provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, June 2010. Length: 26 cm (10.2 inches).

Roughjaw Frogfish, Fowlerichthys avalonis. Fish collected live off the coastal waters off Loreto, Baja California Sur, January 2023.  Length: 42 cm (17 inches).

Roughjaw Frogfish, Fowlerichthys avalonis. Fish provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, May 2011. Length: 53 cm (21 inches) which establishes a new maximum length for this species by a full 17 cm (6.7 inches).

The Roughjaw Frogfish, Fowlerichthys avalonis, is a member of the Frogfish or Antennariidae Family, and is known in Mexico as ranisapo antenado. Globally, there are five species in the genus Fowlerichthys, of which three are found in Mexican waters, two in the Atlantic and one in the Pacific Ocean.

The Roughjaw Frogfish has a globose, slightly compressed body with a large oblique mouth featuring numerous small villiform teeth. They are highly variable in color, being found in various shades of yellow, orange, red, brown, or black with pronounced light and dark mottling. They have large black spots surrounded by a narrow orange ring on the rear base of the 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 oval shaped cluster of numerous short vertically aligned appendages that is about 40% of the pole length. The second dorsal spine is 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.

The Roughjaw Frogfish is a sedentary species found on flat sand or muddy bottoms from the intertidal zone at depths up to 305 m (1,000 feet). They reach a maximum of 53 cm (20.9 inches) in length with this length being established by a fish in my possession that is photographed above. 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. The Roughjaw Frogfish is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.

The Roughjaw Frogfish is a resident of all Mexican waters of the Pacific Ocean.

The Roughjaw Frogfish can be confused with the Bandtail Frogfish, Antennatus strigatus (stand alone third dorsal spine with a large pointed hump; short fishing pole) and the Sanguine Frogfish, Antennatus sanguineus (belly with numerous brown spots).

From a conservation perspective the Roughjaw Frogfish is currently considered to be of Least Concern with stable, widely distributed populations. They are of limited value with the exception that they are utilized by the aquarium trade at a modest level.