Flounder is a type of flatfish —a bottom-dwelling marine fish with a thin, laterally flattened body and both eyes on one side of its head.

Quick Scoop

  • Flounder are saltwater flatfish that live on or near the seafloor in coastal areas.
  • They belong to the broader flatfish group (order Pleuronectiformes), which also includes halibut, sole, dab, and turbot.
  • Their bodies are asymmetrical as adults, with both eyes on the upward-facing side so they can lie camouflaged on the ocean bottom.
  • “Flounder” isn’t just one species; it’s a common name for several related flatfish found in Atlantic, Pacific, and European waters.
  • In cooking, flounder is known for its mild, delicate flavor and tender, flaky flesh, often compared with plaice, sole, and halibut.

A bit of extra context

Biologically, flounder are usually placed in families such as Pleuronectidae (right‑eyed flounders) within the flatfish order Pleuronectiformes. They start life shaped like a typical fish, then flatten and have one eye migrate to the other side as they mature, which is why they look so unusual compared with “regular” fish.