Fringed Flounder, Etropus crossotus
The Fringed Flounder, Etropus crossotus, whose common Spanish name is lenguado ribete, is a member of the Sand Flounder or Paralichthyidae Family, known collectively as lenguados areneros in Mexico. Globally there are nine members of the genus Etropus, five of which are found in Mexican waters, two in the Atlantic, two in the Pacific, and one in both the Atlantic and the Pacific.
The Fringed Flounders are left-eyed flat fish with a complete relatively straight lateral line that starts at the top corner of their gill cover. They have elongated oval deep bodies with a depth that is 52 to 56% of standard length. Their eye side has a pale uniform brown appearance with narrow black scale margins. Their blind side is off-white to tan with some males having black pigmentation on their rear half. They have a short pointed head and a short very small mouth that does not reach the front edge of their large eyes. Their eyes are set very close together with the lower eye slightly in front of the top eye. They have 59 to 70 anal rays and 75 to 89 dorsal rays. Their caudal fin has a blunt angular point, their pectoral fin is 50 to 75% of head length, and their pelvic fins originate mid-body. They have 6 to 10 gill rakers on their lower arch and are covered with small rough scales.
The Fringed Flounders are bottom dwellers found over and within sandy and muddy bottoms at depths up to 355 feet. They are known to enter brackish and marine waters. They reach a maximum length of 22.0 cm (8.7 inches). They are optimistic and well-camouflaged ambush predators that lie in wait half submerged on the ocean floor.
In Mexican waters the Fringed Flounder ares found in all waters of the Atlantic and the Pacific with the exception that they are absent from Guerrero Negro northward along the central and northwest coasts of Baja.
The Fringed Flounders, although fairly common in some locations, are too small to be of interest to most. They are caught with some frequency as a by-catch of deep water shrimp trawlers.