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Butter sole (Isopsetta isolepis) — Pleuronectidae

Butter sole

Isopsetta isolepis
LC · Least Concern

The Butter sole (Isopsetta isolepis) is a saltwater fish of the family Pleuronectidae that grows up to 55 cm.

Length
55 cm
Water
Saltwater
Depth
20–425 m
Diet
Carnivore
Behaviour
Solitary
Body shape
Flat / disc-shaped
Substrate
Sand / mud bottom
Danger
Harmless
Range
Eastern Pacific, from Alaska to California.
Edibility
Commonly eaten

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Description

The butter sole is a right-eyed flatfish of the family Pleuronectidae from the eastern Pacific, from Alaska to California. The species reaches about 55 cm; both eyes lie on the right side and the eyed side is brown with a smooth, 'buttery' skin. It is common in shallow water on soft, silty bottoms. In summer it moves into shallow water and in winter to deeper water, to about 425 m; spawning fish make north-south migrations. The diet consists of polychaete worms, young herring, shrimps and sand dollars. It is a tasty food fish sometimes marketed.

Frequently asked questions

How do you recognise the Butter sole?

The Butter sole has a flattened, disc-shaped body, is mainly brown and shows a marbled pattern. Right-sided flatfish with smooth, 'buttery' skin; makes seasonal migrations.

Where does the Butter sole live?

The Butter sole lives in the sea (marine waters) and is mostly found around sand or mud bottom. Eastern Pacific, from Alaska to California.

How big does the Butter sole get?

The Butter sole grows to a maximum of about 55 cm. On average the species is around 30 cm.

Is the Butter sole dangerous to humans?

No, the Butter sole is harmless to humans. None required: this species is harmless to humans.

Is the Butter sole edible?

Yes, the Butter sole is commonly eaten.

More photos

Butter sole (Isopsetta isolepis) — Pleuronectidae — 2
iNaturalist ((c) kelpadelpian, some rights reserved (CC BY-NC))
Butter sole (Isopsetta isolepis) — Pleuronectidae — 3
Wikimedia Commons — California. Dept. of Fish and Game; California. Fish and Game Commission; California. Division of Fish and Game (Public domain)
Butter sole (Isopsetta isolepis) — Pleuronectidae — 4
iNaturalist ((c) olibegarden, some rights reserved (CC BY-NC))
Butter sole (Isopsetta isolepis) — Pleuronectidae — 5
iNaturalist ((c) shrom1234, some rights reserved (CC BY-NC))

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All data

Identification

English name
Butter sole verified
Scientific name
Isopsetta isolepis
Family
Pleuronectidae
Other names
Butter sole verified

Appearance

Size class
Large verified
Max length (cm)
55 verified
Average length (cm)
30 verified
Body shape
Flat / disc-shaped sourced
Dominant colour
Brown
Pattern
Marbled
Tail shape
Rounded
Mouth position
Terminal
Lips
Thin
Barbels
No sourced
Dorsal fins
One continuous
Dorsal spines
No sourced

Habitat & distribution

Water type
Saltwater sourced
Substrate
Sand / mud bottom sourced
Min depth (m)
20 verified
Max depth (m)
425 verified
Natural range
Eastern Pacific, from Alaska to California.
Origin
Native sourced

Behaviour & biology

Diet
Carnivore sourced
Diet (detail)
Polychaetes, juvenile herring, shrimps and sand dollars sourced
Social behaviour
Solitary
Territorial
No
Reproduction
Separate sexes sourced
Sexual dimorphism
No
Max. age (years)
11 verified
Seasonality
Migrates to shallow water in summer and to deeper water in winter; spawning fish make north-south migrations.
Special features
Right-sided flatfish with smooth, 'buttery' skin; makes seasonal migrations. sourced

For anglers

Edibility
Commonly eaten sourced
Fishing method
Bottom fishing with natural bait (worm, shrimp or fish) on or just above the seabed.
Regulations source

Safety

Danger to humans
Harmless sourced
First aid
None required: this species is harmless to humans. sourced

Status & sources

Sources
FishBase via GBIF (DwC-A), CC-BY-NC 4.0

More from the family Pleuronectidae

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