The Canadian Encyclopedia — neutral, cited, updated
July 26, 2026Sources cited
Canadianwire.
Canada’s encyclopedia & explainer
HomeScience & NatureMarine BiologySole fish
Science & Nature • Marine Biology

Sole fish

Sole fish are flatfishes, especially members of the family Soleidae, although the name is also used more broadly for some similar flatfish in other families.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 26, 2026|2 min read| Fact-checked

Sole fish are flatfishes, especially members of the family Soleidae, although the name is also used more broadly for some similar flatfish in other families. They are bottom-dwelling marine fish, many of which are commercially important food species. The common or Dover sole (Solea solea) is one of the best-known examples.

Classification and naming

The term "sole" is used for several kinds of flatfish, but most strictly refers to species in the family Soleidae. Outside Europe, the name is sometimes applied more loosely to other similar flatfish, including some flounders.

Physical characteristics

Soles are flattened fishes with both eyes on one side of the head, an adaptation to living on the seafloor. They are often oval or elongated in shape and are typically colored to blend with sandy or muddy bottoms.

Habitat and diet

Soles live in marine and brackish waters, and some related species occur in freshwater. They are bottom-dwelling fish that commonly feed on worms, crustaceans, and other small invertebrates.

Human use

Several sole species are valuable commercial food fish. The common sole is especially well known in northern Europe and the Mediterranean, where it is harvested and eaten widely.

Key facts

  • Sole is a common name for several flatfish species, not a single species.
  • In a stricter sense, soles belong to the family Soleidae.
  • They are adapted to life on the sea floor and are typically bottom-dwelling fishes.
  • Many soles feed on small crustaceans, worms, and other invertebrates.
  • The common sole (Solea solea) is a well-known species in Europe and the Mediterranean.
🍁
Canadian context

Sole is sold and eaten in Canada as a seafood product, but the term refers to multiple flatfish rather than one uniquely Canadian species.

Frequently asked questions

Is sole fish a single species?
No. "Sole" is a common name for several flatfish species, though it most often refers to the family Soleidae.
What family do true soles belong to?
True soles belong to the family Soleidae.
Where do sole fish live?
They live mainly in marine and brackish waters near the sea floor, often over sand or mud.
What do sole fish eat?
They feed mainly on small crustaceans, worms, and other bottom-dwelling invertebrates.
Why are sole fish flattened?
Their flattened body shape helps them live on the ocean floor and remain camouflaged in sediment.
Is Dover sole the same as true sole?
Not always. In Europe, Dover sole usually refers to Solea solea, but some Pacific fish sold as Dover sole are not true soles.

References

  1. Wikipediahttps://en.wikipedia.org/wiki/Sole_(fish)
    Supports: General definition of sole as a group of flatfish in several families.
  2. North Western Inshore Fisheries and Conservation Authorityhttps://www.nw-ifca.gov.uk/managing-sustainable-fisheries/species/fish/sole/
    Supports: Common sole identification, habitat, size, and distribution.
  3. Wikipediahttps://en.wikipedia.org/wiki/Soleidae
    Supports: Family Soleidae, diversity, habitat range, and feeding habits.
  4. Encyclopaedia Britannicahttps://www.britannica.com/animal/sole-fish-family
    Supports: Restricted meaning of sole, physical characteristics, and species diversity.