Yellowtail Flounder

The yellowtail flounder is a right-eyed flatfish in the family Pleuronectidae, native to the continental shelf of the northwest Atlantic Ocean from Labrador to the Chesapeake Bay area. It is a demersal species that spends its adult life on sandy bottoms, where its flattened body and cryptic coloration help it blend with the seafloor. Yellowtail flounder is one of the more slender-bodied members of the flounder family, and it is easily distinguished by the rusty-yellow tint along its tail margin, which gives the species its common name. It supports a long-standing commercial fishery across parts of its range, and populations have been the subject of ongoing stock assessment and management due to historical overfishing pressure.

• Elongated, oval body that is noticeably slimmer than many other flatfish
• Eyes and coloration on the right side; upper side is reddish-brown to olive with faint darker blotches
• Underside is white to pale cream
• Caudal (tail) fin edged with a distinct rusty-yellow to orange tint, most visible near the base of the tail
• Small head and mouth relative to body length
• Adults typically reach 30-55 cm

The yellow-tinged tail separates it from the similar winter flounder, which has a thicker body and a more uniformly dark, unmarked tail, and from American plaice, which is larger-bodied with rougher scales.

Yellowtail flounder occupy the continental shelf of the northwest Atlantic, ranging roughly from the Grand Banks and Gulf of St. Lawrence south to the Mid-Atlantic Bight. They live on sand or sand-mud bottoms at depths generally between 35 and 90 meters, though they range from very shallow water to over 300 meters. The species prefers cooler continental shelf waters and tends to avoid muddy or highly silted substrates in favor of firmer sandy ground where it can burrow shallowly and remain camouflaged.

Yellowtail flounder are solitary, bottom-oriented fish that lie partially buried in sand during the day and become more active in feeding at dusk and after dark. They are carnivorous, preying on small invertebrates such as polychaete worms, amphipods, and other crustaceans found on or just above the seafloor. The species undertakes seasonal migrations, moving into shallower water in spring and summer to spawn and retreating to deeper, warmer water in winter. Spawning occurs over sandy shelf habitat, with females releasing large numbers of buoyant, pelagic eggs that drift and hatch before larvae eventually settle to the bottom and metamorphose into the flattened juvenile form.