The rock sole (''Lepidopsetta bilineata''), also known as the Pacific rock sole or Southern rock sole is a

flatfish A flatfish is a member of the Ray-finned fish, ray-finned demersal fish Order (biology), suborder Pleuronectoidei, also called the Heterosomata. In many species, both eyes lie on one side of the head, one or the other migrating through or around ...

of the family

Pleuronectidae Pleuronectidae, also known as righteye flounders, are a family of flounders. They are called "righteye flounders" because most species lie on the sea bottom on their left sides, with both eyes on their right sides. The Paralichthyidae are the o ...

. It is a

demersal fish Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes (the demersal zone).Walrond Carl . "Coastal fish - Fish of the open sea floor"Te Ara - the Encyclopedia of New Zealand. Updated 2 March 2009 They oc ...

that lives on sand and gravel bottoms at depths of up to , though it is most commonly found between . Its native habitat is the

temperate In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...

waters of the northern

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the cont ...

, from

Baja California Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

, the

Aleutian Islands The Aleutian Islands ( ; ; , "land of the Aleuts"; possibly from the Chukchi language, Chukchi ''aliat'', or "island")—also called the Aleut Islands, Aleutic Islands, or, before Alaska Purchase, 1867, the Catherine Archipelago—are a chain ...

and southeastern parts of the

Bering Sea The Bering Sea ( , ; rus, Бе́рингово мо́ре, r=Béringovo móre, p=ˈbʲerʲɪnɡəvə ˈmorʲe) is a marginal sea of the Northern Pacific Ocean. It forms, along with the Bering Strait, the divide between the two largest landmasse ...

. It grows up to in length and can weigh up to , and has a maximum recorded lifespan of 22 years.

Taxonomy and nomenclature

Prior to 2000 the

Northern rock sole The northern rock sole (''Lepidopsetta polyxystra'') is a flatfish of the family Pleuronectidae. It is a demersal fish that lives on sand, mud and gravel bottoms at depths of up to , though it is most commonly found between . Its native habitat i ...

and the rock sole, ''Lepidopsetta bilineata'', were considered to be a single species under the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

Lepidopsetta ''Lepidopsetta'' is a genus of righteye flounders native to the North Pacific Ocean North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, a ...

'', but work by Orr & Matarese published in 2000 reorganised the genus into three separate

taxa In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

. As a result of this reclassification and renaming, the rock sole may be referred to as the "southern" rock sole, in order to avoid confusion with the Northern rock sole ''L. polyxystra''.

Description

The rock sole is a right-eyed flounder. Its upper surface is grey to olive to dark brown or black, lighter or darker mottling, and is sometimes marked with yellow or red spots; the underside is light. Its dorsal and anal fins have dark blotches or bars, and near the tail fins may be yellowish. The

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

is convex – rounded or broadly v-shaped. It has a small mouth with fleshy lips, and teeth are more strongly developed on the underside. The rock sole is common from the eastern Bering Sea to central California. They can grow to an overall length of 63.5 cm (25 in).Miller and Lea's Guide to the Coastal Marine Fishes of California (pg. 345)

Role in ecosystem

The rock sole occupies a moderately high

trophic level The trophic level of an organism is the position it occupies in a food web. Within a food web, a food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the ...

in the

food chain A food chain is a linear network of links in a food web, often starting with an autotroph (such as grass or algae), also called a producer, and typically ending at an apex predator (such as grizzly bears or killer whales), detritivore (such as ...

Diet

The diet of the rock soles consists mainly of

zoobenthos Benthos (), also known as benthon, is the community of organisms that live on, in, or near the bottom of a sea, river, lake, or stream, also known as the benthic zone.mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

brittle star Brittle stars, serpent stars, or ophiuroids (; ; referring to the serpent-like arms of the brittle star) are echinoderms in the class Ophiuroidea, closely related to starfish. They crawl across the sea floor using their flexible arms for locomot ...

marine worm Any worm that lives in a ocean, marine environment (biophysical), environment is considered a sea or marine worm. Marine worms are found in several different phylum (biology), phyla, including the Platyhelminthes, Nematoda, Annelida (segmented ...

s and other fish.

Predators

Rock soles are eaten by marine mammals and other fish, including

shark Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the ...

Alaska pollock The Alaska pollock or walleye pollock (''Gadus chalcogrammus'') is a marine fish species of the cod genus ''Gadus'' and family Gadidae. It is a semi-pelagic Shoaling and schooling, schooling fish widely distributed in the North Pacific Ocean, No ...

yellowfin sole The yellowfin sole (''Limanda aspera'') is a flatfish of the family Pleuronectidae. It is a demersal fish that lives on soft, sandy bottoms at depths of up to , though it is most commonly found at depths of around . Its native habitat is the temp ...

Pacific halibut The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the continen ...

and

Pacific cod The Pacific cod (''Gadus macrocephalus)'' is a species of ray-finned fish in the family Gadidae. It is a bottom-dwelling fish found in the northern Pacific Ocean, mainly on the continental shelf and upper slopes, to depths of about . It can grow ...

Reproduction

Rock soles reach reproductive maturity at between 4 and 7 years old, and

spawn Spawn or spawning may refer to: * Spawning, the eggs and sperm of aquatic animals Arts, entertainment and media * Spawn (character), a fictional character in the comic series of the same name and in the associated franchise ** ''Spawn: Armageddon' ...

in winter through to early spring. Eggs are demersal and stick to the surface on which they are laid; hatching takes from 6 to 25 days.

Commercial fishing

The rock sole is fished commercially, and forms an important part of two

trawl Trawling is an industrial method of fishing that involves pulling a fishing net through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch di ...

fisheries Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life or, more commonly, the site where such enterprise takes place ( a.k.a., fishing grounds). Commercial fisheries include wild fisheries and fish farm ...

in the Bering Sea and

Gulf of Alaska The Gulf of Alaska ( Tlingit: ''Yéil T'ooch’'') is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the ...

. Although it was

overfished Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in the ...

in the 1960s stocks have recovered, and the

biomass Biomass is a term used in several contexts: in the context of ecology it means living organisms, and in the context of bioenergy it means matter from recently living (but now dead) organisms. In the latter context, there are variations in how ...

of rock sole in the Bering Sea and Aleutian Islands population is now estimated to be very high, at twice the level required to support

maximum sustainable yield In population ecology and economics, maximum sustainable yield (MSY) is theoretically, the largest yield (or catch) that can be taken from a species' stock over an indefinite period. Fundamental to the notion of sustainable harvest, the concept o ...

. In 2008 the estimated rock sole biomass in the Gulf of Alaska fishery was some 161,617 tons, compared to catches ranging from 1,468 tons in 2004 to 4,260 tons in 2007. Alaska accounts for the majority of the worldwide harvest of this fish, catching over 52,000 tons of rock sole in 2008. Rock sole fishing off the coast of the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

is managed by the Pacific Fishery Management Council and the North Pacific Fishery Management Council, two of eight

U.S. Regional Fishery Management Councils The eight U.S. regional fishery management councils are the primary forums for developing conservation and management measures for U.S. marine fishery, fisheries. The regional councils recommend management measures for fisheries in the Exclusive E ...

References

{{Authority control

rock sole The rock sole (''Lepidopsetta bilineata''), also known as the Pacific rock sole or Southern rock sole is a flatfish of the family Pleuronectidae. It is a demersal fish that lives on sand and gravel bottoms at depths of up to , though it is most c ...

Fish of the Pacific Ocean Western North American coastal fauna Commercial fish

Taxa named by William Orville Ayres