The C-O sole, Pleuronichthys coenosus, is a flatfish

Flatfish

The flatfish are an order of ray-finned fish, also called the Heterosomata, sometimes classified as a suborder of Perciformes. In many species, both eyes lie on one side of the head, one or the other migrating through and around the head during development...

 of the family Pleuronectidae

Pleuronectidae

Righteye flounders are a family, Pleuronectidae, of flounders. They are called "righteye flounders" because most species lie on the sea bottom on their left side, with both eyes on the right side. The Paralichthyidae are the opposite, with their eyes on the left side.Their dorsal and anal fins are...

. It is a demersal fish that lives on flat bottoms and rocky areas at depths of between 18 and 350 m (59.1 and 1,148.3 ft). Its native habitat is the subtropical

Subtropics

The subtropics are the geographical and climatical zone of the Earth immediately north and south of the tropical zone, which is bounded by the Tropic of Cancer and the Tropic of Capricorn, at latitudes 23.5°N and 23.5°S...

 waters of the eastern Pacific

Pacific Ocean

The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

, ranging from Sitka, Alaska

Alaska

Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...

 in the north to San Quintín

San Quintín, Baja California

San Quintín is a coastal town on the west coast of the Mexican state of Baja California, in the municipio of Ensenada. San Quintín has beautiful beaches and several places for tourists to stay. Tourists can enjoy fishing, camping, bird watching, surfing, and clam digging...

, Baja California

Baja California

Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...

 in the south. It can grow up to 36 centimetres (14.2 in) in length.

Nomenclature

The C-O sole gets its name from the markings on its caudal fin: a crescent shape and a ring, which resemble a letter C and a letter O.

Description

The C-O sole is a right-eyed flatfish with large, bulbous eyes located near the tip of the snout. The upper surface is mottled light to dark brown, with occasional white spots; there is usually a prominent mid-body dark spot with a pale patch behind it. The underside is light. There is a dark crescent-shaped marking and a large dark spot on the caudal fin, which together resemble the letters "C-O".

Diet

The diet of the C-O sole consists mainly of zoobenthos

Benthos

Benthos is the community of organisms which live on, in, or near the seabed, also known as the benthic zone. This community lives in or near marine sedimentary environments, from tidal pools along the foreshore, out to the continental shelf, and then down to the abyssal depths.Many organisms...

 polychaete

Polychaete

The Polychaeta or polychaetes are a class of annelid worms, generally marine. Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. Indeed, polychaetes are sometimes referred to as bristle worms. More than 10,000...

s, bivalves and amphipods

Amphipoda

Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. The name amphipoda means "different-footed", and refers to the different forms of appendages, unlike isopods, where all the legs are alike. Of the 7,000 species, 5,500 are classified...

.