Bigmouth Sanddab, Citharichthys gilberti
The Bigmouth Sanddab, Citharichthys gilberti, whose common Spanish name is lenguado tapadera, is a member of the Sand Flounder or Paralichthyidae Family, known collectively as lenguados areneros in Mexico. Globally, there are twenty four members of the genus Citharichthys, nine of which are found in Mexican waters, one in the Atlantic and eight in the Pacific. All family members are left-eyed fish and have either a straight or arched lateral line.
The Bigmouth Sanddabs have elongated oval bodies with a depth that is 41 to 45% of standard length. Their eye side is brown with darker brown mottling and scattered white flecks and blotches. Their anal and dorsal fins have dark spots. Their blind slide is off-white to tan. They fade quickly to a uniform brown color upon collection. Their head is relatively short with a medium-sized mouth that ends under the center of their lower eye. Their eyes are mid-sized and separated with the lower eye preceding the upper eye. They have one series of immovable teeth on each jaw and lack canines. They have 57 to 65 anal rays and 76 to 89 dorsal rays. Their caudal fin is slightly rounded. The pectoral fin on the eye side is approximately 50% of the head length. They have 13 or 14 long slender gill rakers on their lower arch and are covered with rough scales on both sides of their body. Their lateral line is straight and extends from the gill covers to the caudal fin base.
The Bigmouth Sanddabs are bottom dwellers found over sandy and muddy bottoms in bays, estuaries, and fresh water at depths up to 120 feet. They reach a maximum length of 30 cm (12 inches) and 225 grams (0.5 lb) in weight. They consume a wide variety of crustaceans and small fish and are preyed upon by various marine mammals, larger fish, and sea birds. They are masters at camouflage and can rapidly change colors to match their substrate. They have a lifespan of up to ten years.
In Mexican waters the Bigmouth Sanddabs are found in all waters of the Pacific with the exception that they are absent from Guerrero Negro northward along the central and northwest coasts of Baja and for the northern 20% of the Sea of Cortez.
The Bigmouth Sanddab can be easily confused with the Beach Flounder, Syacium latifrons (7 or 8 lower gill rakers), the Five-Rayed Sanddab, Citharichthys mariajorisae (15 to 17 lower gill rakers), the Gulf Sanddab, Citharichthys fragilis (narrow body, 4 to 10 lower gill rakers), and the Pacific Sanddab, Citharichthys sordidus (narrower body).
The Bigmouth Sanddabs are a minor component of the commercial fishery with the majority of fish taken as a by-catch of deep water trawls. Although small and rare, they are considered an excellent food fish.
Bigmouth Sanddab, Citharichthys gilberti. Fish provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, April 2010. Length: 7.5 cm (3.0 inches). Identification courtesy of H.J. Walker, Jr., Scripps Institution of Oceanography, La Jolla, CA.