Fauna
Fish

Olive Flounder

Paralichthys olivaceus

Also known as Bastard Halibut, Japanese Flounder, Korean Halibut

Olive flounder lie camouflaged against sandy ocean bottoms, blending seamlessly into coastal sediments while waiting to ambush passing prey. Both eyes migrate to the left side of the body during larval metamorphosis, leaving a mottled brown upper surface that mimics surrounding silt. These fast-growing flatfish inhabit temperate waters across the Northwestern Pacific, serving as major bottom-dwelling predators.

CamouflagedMarinePredatory
—observations
—countries
—peak records
Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Diet & preySmall fish, Shrimp, Squid
Predators
  • Sharks
  • Marine mammals
  • Large predatory fish
ThreatsOverfishing, coastal development, marine pollution
HabitatsCoastal marine waters, estuaries, sandy or muddy seabeds
Life span10–15 years
  1. FamilyParalichthyidae
  2. SpeciesParalichthys olivaceus
Range data is not available yet.
Interaction riskLow
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is low
Safe to observe from a respectful distance while diving or swimming.
Responsible observation
  • Spotting Cues: Search sandy seabeds for two dark eyes protruding above buried silt.
  • Observing Etiquette: Maintain steady buoyancy to avoid disturbing benthic habitats or scaring flatfish.
Help improve the field guideSomething wrong?

Report a name, category, or profile issue for review.

Checking your Fauna account…