Paralichthys lethostigma, the southern flounder, is a species of large-tooth flounders native to the eastern and gulf coasts of the United States. It is a popular sports fish and is the largest and most commercially valuable flounder in the western North Atlantic Ocean and Gulf of Mexico. It is a “left-eyed flounder”, meaning the left side is pigmented and is the “up side”.
The body color is brown with diffuse, unocellated spots and blotches. This species typically grows to around 12-14 inches in length.
Southern flounders are a major and valuable species in the highly important commercial and recreational flounder fishery in the Gulf of Mexico. Most of the commercial catch in the Gulf of Mexico is incidental to the catch by shrimp trawlers. Recreationally, they can easily be caught by anglers on a line with either a lure or live bait. Another popular form of collecting flounders is by night gigging. In this sport, anglers use a gig, or a multi-pronged spear, to impale the fish after using a flashlight to spot it in the waters at night.
Southern flounder are also considered valuable as an aquaculture species because of their ability to live in water of varying salinities. Research has been conducted on using soy based protein sources rather than fish meal to grow the fish to reduce environmental impact.