The European plaice (''Pleuronectes platessa''), commonly referred to as simply plaice, is a species of marine

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 ...

in the genus Pleuronectes 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 ...

Description

The European plaice is characterized, on their dorsal side, by their dark green to dark brown skin, blotched with conspicuous, but irregularly distributed, orange spots. The ventral side is pearly white. The skin is smooth with small scales. They are able to adapt their colour somewhat to match that of their surroundings, but the orange spots always remain visible. The skin lacks any prickles. The outline of adults is oval. The head is rather small and is less than 25% of the total length. The pointed mouth is terminal and fairly small with its

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

reaching just below the right eye. Both eyes are located at the right side of the body. The bony ridge behind the eyes is another characteristic for this species. The

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelia ...

curves slightly above the

pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

. The dorsal fin reaches the eye. The dorsal and anal fins are distant from the caudal fin. The

anal 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 o ...

contains 48 to 59 soft rays and is preceded by a spine. The

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

has 65 to 79 soft rays, the pectoral fin 10 to 11, and the ventral fin six. European plaice can live up to 20 years and will reach its maximum size at about 50 to 70 cm but individuals up to 78 cm and 5.7 kg have been observed.

Distribution and habitat

European plaice is a common flatfish which inhabits sandy and muddy bottoms of the European shelf, usually at depths between 10 and 200 m. It is found from the

Barents Sea The Barents Sea ( , also ; , ; ) is a marginal sea of the Arctic Ocean, located off the northern coasts of Norway and Russia and divided between Norwegian and Russian territorial waters.World Wildlife Fund, 2008. It was known earlier among Russi ...

down to the

Iberian peninsula The Iberian Peninsula ( ), also known as Iberia, is a peninsula in south-western Europe. Mostly separated from the rest of the European landmass by the Pyrenees, it includes the territories of peninsular Spain and Continental Portugal, comprisin ...

and around

Iceland Iceland is a Nordic countries, Nordic island country between the Atlantic Ocean, North Atlantic and Arctic Oceans, on the Mid-Atlantic Ridge between North America and Europe. It is culturally and politically linked with Europe and is the regi ...

and the

Faroe Islands The Faroe Islands ( ) (alt. the Faroes) are an archipelago in the North Atlantic Ocean and an autonomous territory of the Danish Realm, Kingdom of Denmark. Located between Iceland, Norway, and the United Kingdom, the islands have a populat ...

. It is often reported in ichthyological check lists for the

Mediterranean Sea The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Eur ...

but this is likely to be misidentified specimens of

European flounder The European flounder (''Platichthys flesus'') is a flatfish of European coastal waters from the White Sea in the north to the Mediterranean and the Black Sea in the south. It has been introduced into the United States and Canada accidentally th ...

. Adult fish are generally found in deeper waters whereas young fish are found in shallow waters e.g. estuaries and sandy coasts. Plaice tend to burrow in the sediment during the day and remain stationary for long periods to avoid predators and ambush prey.

Diet

It is active at night and feeds on

polychaetes Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are m ...

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

and

bivalves Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed by a calcified exoskeleton consis ...

. Young plaice (between 1 and 2 years old) tend to consume mainly

shrimp A shrimp (: shrimp (American English, US) or shrimps (British English, UK)) is a crustacean with an elongated body and a primarily Aquatic locomotion, swimming mode of locomotion – typically Decapods belonging to the Caridea or Dendrobranchi ...

Lifecycle

The main spawning grounds in the North Sea are located in the

Southern Bight Southern Bight, also known as the Flanders Bight, and (in Dutch) the Hoofden, is the southern bight of the North Sea bounded by the coasts of the Netherlands, Belgium, France and Great Britain. The Southern Bight is south west of the German Bight ...

and in the eastern

English Channel The English Channel, also known as the Channel, is an arm of the Atlantic Ocean that separates Southern England from northern France. It links to the southern part of the North Sea by the Strait of Dover at its northeastern end. It is the busi ...

. Plaice are determinate spawners in which

fecundity Fecundity is defined in two ways; in human demography, it is the potential for reproduction of a recorded population as opposed to a sole organism, while in population biology, it is considered similar to fertility, the capability to produc ...

is determined before the onset of spawning. Females mature, i.e. are able to spawn, at ages from 3 to 7 years. However, in the

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

, most females mature at 3 years.

Ovary The ovary () is a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/ oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are end ...

development begins around late August to September with the spawning being from December to May. Each female releases eggs in batches every 3 to 5 days for around a month. The eggs hatch after about two weeks and drift passively in the

plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...

. The

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e drift in the plankton and

metamorphose Metamorphosis is a biological process by which an animal physically developmental biology, develops including birth, birth transformation or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through ...

after about 8 to 10 weeks, dependent on temperature, at which time they settle in the intertidal zone of sandy beaches. The larvae exhibit what is sometimes called semiactive tidal transport. As the larvae cannot swim against the prevailing currents, they make use of their ability to alter their vertical position in the water column to ensure they are transported to suitable habitat. On incoming or flood tides (water level is rising), the larvae move up into the water column and are thus transported towards land. On the outgoing or ebb tides (water level is falling), the larvae move down the water column and are not transported away from the intertidal by the tidal currents. When the larvae have reached a suitable site for settlement, the metamorphosis to the asymmetric body shape takes place. This can take up to 10 days. Recently transformed juveniles settle onto shallow intertidal beaches. The very youngest juveniles will, for a period of up to a week, strand themselves in very shallow pools on the intertidal once the tide has receded. The reasons for this behaviour are not clear. During the first year of life (when the fish are called 0+ group), the juveniles will stay in these shallow intertidal habitats for up to 7 months (depending on latitude and/or temperature), before migrating to deeper waters. Some of these fish will return the next year (when they are I+ group) and even fewer when they are II+ group; however, the majority of juveniles do not return after they have migrated during their first year.

Fisheries

European plaice are generally caught as part of a mixed flatfish fishery or in other

groundfish 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 ...

fisheries. The most common gears used in these fisheries are beam trawls, otter trawls and Danish seine. It is also caught in other fishing gears such as bottom set

gillnets Gillnetting is a fishing method that uses gillnets: vertical panels of netting that hang from a line with regularly spaced floaters that hold the line on the surface of the water. The floats are sometimes called "corks" and the line with corks is ...

, longlines and hand lines. The majority of landings of European plaice are caught in the

. Total landings peaked in 1985–1990 when approximately 200 thousand tonnes were landed, current landings are generally less than 120 thousand tonnes. After a period of time in the 1980s and 1990s where landings exceeded management advice for several stocks, the fishing pressure has been reduced and the status of the stocks has improved and all the stocks are considered to be within safe biological limits as defined by ICES.

As a food

Plaice is sometimes used as the fish in

fish and chips Fish and chips is a hot dish consisting of batter (cooking), battered and fried fish, served with French fries, chips. Often considered the national dish of the United Kingdom, fish and chips originated in England in the 19th century. Today, ...

, in countries where the dish is popular.Seafish. On Plate. Fish & chips
In North German and

Danish cuisine Danish cuisine originated from the peasant population's own local produce and was enhanced by cooking techniques developed in the late 19th century and the wider availability of goods during and after the Second Industrial Revolution, Industrial ...

, plaice is one of the most commonly eaten fishes. Filleted, battered, and pan-fried plaice is popular hot or cold as an

open sandwich An open sandwich, also known as an open-face/open-faced sandwich, bread baser, bread platter or tartine, consists of a single slice of bread or toast with one or more food items on top. It has half the number of slices of bread compared to a ty ...

topping together with

remoulade Rémoulade (; ) is a cold sauce. Although similar to tartar sauce, it is often more yellowish, sometimes flavored with curry, and often contains chopped Pickled cucumber, pickles or piccalilli. It can also contain horseradish, paprika, Anchovies ...

sauce and lemon slices. Battered plaice can also be served hot with

french fries French fries, or simply fries, also known as chips, and finger chips (Indian English), are '' batonnet'' or '' julienne''-cut deep-fried potatoes of disputed origin. They are prepared by cutting potatoes into even strips, drying them, and f ...

and remoulade sauce as a main dish; this fish and chips variant is commonly available as a children's special in Danish restaurants. Breaded frozen plaice, ready to be baked or fried at home, is readily available in supermarkets. Fresh plaice is also oven-baked.

References

* Cooper, J.A. and F. Chapleau (1998). Monophyly and intrarelationships of the family Pleuronectidae (Pleuronectiformes), with a revised classification. ''Fish. Bull., U.S.'' 96(4):686-726. * * (1991). Changes in fecundity of female North Sea plaice (''Pleuronectes platessa'') between three periods since 1900. ''ICES Journal of Marine Science'' 48:253-280. * (1953). ''The plaice'' being the buckland lectures. Publisher Edward Arnold. * (2004). ''Flatfishes: Biology and Exploitation''. Blackwell Publishing.

External links

* Guide to Responsible Sourcing of Plaice - produced by Seafish https://web.archive.org/web/20071008001434/http://www.seafish.org/upload/file/fisheries_management/Plaice%20Factsheet2%20%20final.pdf
Information about plaice
* * {{Taxonbar, from=Q27098 Pleuronectes Commercial fish Fish of the North Sea Fish described in 1758 Taxa named by Carl Linnaeus