Toothed Flounder, Cyclopsetta querna
The Toothed Flounder, Cyclopsetta querna, whose common Spanish name is lenguado dientón, is a member of the Sand Flounder or Paralichthyidae Family, known collectively as lenguados areneros in Mexico. Globally, there are only five members of the genus Cyclopsetta, four of which are found in Mexican waters, two in the Atlantic and two in the Pacific.
The Toothed Flounders are left-eyed flat fish with a straight lateral line that originates just behind their eyes and extends to their caudal base. A small percentage of the population is right-eyed. They have elongated oval bodies with a depth that is 42 to 46% of standard length. Their eye side is dark brown with a few lighter crossbars. There are two or three large black spots on their anal and dorsal fins and a dark blotch in the middle of their caudal fin. Their blind side is off-white. They have a small rounded head with a short snout and a large mouth that ends behind the rear edge of their eyes. Their eyes are large, elevated, parallel, and separated by a flat space. They have one row of immovable teeth on both jaws and a pair of canines at the front of their top jaw (after which they are named). They have 70 to 74 anal rays and 89 to 93 dorsal rays. Their dorsal fin originates before the top eye. Their caudal fin is short and pointed and has a wide base. They have 7 to 10 very short, fat, and most unusually-shaped gill rakers on their lower arch (pictured below – see the Dappled Flounder for more traditionally-shaped gill rakers). They are covered with small smooth scales on both eye and blind sides.
The Toothed Flounders are bottom dwellers found over and within sandy and muddy bottoms at depths up to 300 feet. They are known to enter brackish waters. They reach a maximum length of 44 cm (17 inches), as established by a fish in my possession. They are opportunistic and well-camouflaged ambush predators that lie in wait half submerged on the ocean floor. They prey on small fish and a wide variety of crustaceans.
In Mexican waters the Toothed Flounder and found in all waters of the Pacific with the exception that they are absent from Magdalena Bay northward along the central and northwest coasts of Baja.
The Toothed Flounder can be confused with the California Halibut, Paralichthys californicus (doubly concave caudal fin, 25 to 32 gill rakers), the Cortez Halibut, Paralichthys aestuarius (24 to 31 gill rakers), the Dappled Flounder Paralichthys woolmani (16 to 20 gill rakers), and the Panamic Flounder, Cyclopsetta panamensis (rough eye side scales).
The Toothed Flounder is considered to be an excellent food fish, however they are uncommon and seldom seen by humans. They are normally caught as a by-catch of deep water shrimp trawls taken over sand and mud substrate.
Toothed Flounder, Cyclopsetta querna, Juvenile. Photograph provided by the commercial fishermen of Todos Santos, September, 2014. Length: 14 cm (5.5 inches). Tentative identification courtesy of H.J. Walker, Jr., Scripps Institution of Oceanography, La Jolla, CA.
Toothed Flounder, Cyclopsetta querna. Fish provided by the commercial fishermen of Todos Santos, July, 2010. Length: 39 cm (15 inches). Photo immediately above is of the atypical gill rakers of this species.