Petrale Sole

The petrale sole is a right-eyed flatfish in the family Pleuronectidae, native to the northeastern Pacific Ocean from Alaska to Baja California. Despite the common name "sole," it is more closely related to true flounders than to true soles. Petrale sole is one of the larger and more streamlined flatfish species found along the U.S. and Canadian West Coast, with a relatively firm, smooth-skinned body. It has long supported an important commercial fishery along the Pacific coast, and its populations have been the subject of stock rebuilding efforts following historical declines, making it a species of ongoing fisheries management interest in West Coast groundfish assessments.

• Elongated, oval body, relatively slender compared to bulkier Pacific flatfish
• Eyes on the right side of the head
• Upper side is uniform light brown to olive-brown, generally without bold spots or blotches
• Underside is white
• Lateral line has a moderate arch above the pectoral fin
• Adults typically reach 35-55 cm, with large individuals up to 70 cm

Its plain, unspotted coloration and slender profile distinguish it from Dover sole, which has a more mucus-covered, rougher skin, and from larger, mottled species like California halibut.

Petrale sole range along the northeastern Pacific coast from the Gulf of Alaska south to Baja California, with concentrated populations off Washington, Oregon, and California. They live on sandy or sand-mud seafloor of the continental shelf, typically at depths from about 20 to 400 meters, with adults generally found deeper than juveniles. The species prefers cooler, deeper shelf waters as it matures, moving seasonally between shallower spawning grounds and deeper feeding areas. Firm sand and sand-mud substrates near the shelf break are especially favored, giving the species a fairly continuous distribution along much of the outer coast.

Petrale sole are demersal, moderately active fish that forage along the seafloor for small fish, shrimp, and other invertebrates, using a combination of camouflage and burst swimming to capture prey. They undertake seasonal migrations, moving into deeper offshore waters to spawn during winter months and returning to shallower shelf habitats afterward to feed. Spawning produces pelagic eggs and larvae that drift with currents before settling to the bottom, where juveniles typically occupy shallower nursery habitat than adults. As a shelf-dwelling predator, petrale sole plays a role in coastal food webs both as a consumer of small invertebrates and as prey for larger fish.