C-O Sole

Pleuronichthys coenosus

A small right-eyed flatfish of the temperate eastern Pacific, the C-O sole takes its name from the pattern on its tail fin: a dark crescent beside a round blotch, which together read as the letters C and O. It lies flat on soft and rocky bottoms from Sitka, Alaska south to San Quintin in Baja California, usually somewhere between 18 and 350 m, and reaches about 36 cm. Both eyes sit on the right side of the head and bulge near the tip of the snout. The upper surface is mottled light to dark brown, frequently with a prominent dark spot at mid-body and a pale patch just behind it, while the blind underside stays cream. It feeds on bottom-living invertebrates, chiefly polychaete worms, bivalves and amphipods. Divers usually find it motionless and part-buried on sand near rocky reef and kelp rather than swimming in the open.