Demersal fish live on or near the bottom of the
seaAn ocean is a large body of saline water, and a principal component of the hydrosphere. Approximately 75% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
or
lakeA lake is a terrain feature , a body of liquid on the surface of a world that is localized to the bottom of basin and moves slowly if it moves at all. Another definition is, a body of fresh or salt water of considerable size that is surrounded by land...
s. In coastal waters they are found on or near the
continental shelfThe continental shelf is the extended perimeter of each continent and associated coastal plain, and was part of the continent during the glacial periods, but is undersea during interglacial periods such as the current epoch by relatively shallow seas and gulfs. The continental rise is below the...
, and in deep waters they are found on or near the continental slope or along the continental rise. They are not generally found in the deepest waters, such as
abyssalThe abyssal zone is the abyssopelagic layer of pelagic zone that contains the very deep benthic communities near the bottom of oceans. "Abyss" is from the Greek word meaning "bottomless sea". At depths of 4,000 to 6,000 meters , this zone remains in perpetual darkness and never receives daylight...
depths or on the
abyssal plainAbyssal plains are flat or very gently sloping areas of the deep ocean basin floor. They are among the Earth's flattest and smoothest regions and the least explored. Abyssal plains cover approximately 40% of the ocean floor and reach depths between...
, but they can be found around
seamountA seamount is a mountain rising from the ocean seafloor that does not reach to the water's surface , and thus is not an island. These are typically formed from extinct volcanoes, that rise abruptly and are usually found rising from a seafloor of 1,000–4,000 meters depth...
s and islands. They occupy sea floors and lake beds which can consist of mud, sand, gravel or rocks. The word
demersal comes from the
LatinLatin is an Italic language originally spoken in Latium and Ancient Rome. Through the Roman conquest, Latin spread throughout the Mediterranean and a large part of Europe...
demergere, which means
to sink.
Demersal fish are
bottom feederDemersal fish live on or near the bottom of the sea or lakes. In coastal waters they are found on or near the continental shelf, and in deep waters they are found on or near the continental slope or along the continental rise. They are not generally found in the deepest waters, such as abyssal...
s. They can be contrasted with
pelagic fishPelagic fish live in the water column of coastal, ocean and lake waters, but not on the bottom of the sea or the lake. They can be contrasted with demersal fish, which do live on or near the bottom, and reef fish which are associated with coral reefs....
which live and feed away from the bottom in the open water column. Demersal fish contain little oil (one to four percent), whereas pelagic fish fillets can contain up to 30 percent.
Types
Demersal fish can be divided into two main types:
benthicThe benthic zone is the ecological region at the lowest level of a body of water such as an ocean or a lake, including the sediment surface and some sub-surface layers. Organisms living in this zone are called benthos. They generally live in close relationship with the substrate bottom; many such...
fish which rest on the sea floor, and
benthopelagic fish which float in the water column just above the sea floor.
Benthopelagic fish have
neutral buoyancyNeutral buoyancy is a condition in which a physical body's mass equals the mass it displaces in a surrounding medium. This offsets the force of gravity that would otherwise cause the object to sink...
, so they can float at depth without much effort, while benthic fish are more dense, with negative buoyancy so they can lie on the bottom without any effort. Most demersal fish are benthopelagic.
As with other bottom feeders, a mechanism to deal with substrate is often necessary. With demersal fish the sand is usually pumped out of the mouth through the gill slit. Most demersal fish exhibit a flat ventral region so as to more easily rest their body on the substrate. The exception may be the flatfish, which are laterally depressed but lie on their sides. Also, many exhibit what is termed an "inferior" mouth, which means that the mouth is pointed downwards; this is beneficial as their food is often going to be below them in the substrate. Those bottom feeders with upward-pointing mouths, such as
stargazerThe stargazers are a family Uranoscopidae of perciform fish that have eyes on top of their heads . The family includes about 50 species in 8 genera, all marine and found worldwide in shallow waters....
s, tend to seize swimming prey.
Benthic fish
Benthic fish, sometimes called
groundfishGroundfish are fish that live on, in, or near the bottom of the body of water they inhabit. Some typical saltwater groundfish species are sole, flounder, and halibut....
, stay largely in contact with the sea floor. They either lie-and-wait as
ambush predatorAmbush predators or sit-and-wait predators are carnivorous animals that capture prey by stealth or cunning, not by speed or necessarily by strength. These organisms usually hide motionless and wait for prey to come within striking distance. They are often camouflaged, and may be solitary...
s or move actively over the bottom in search for food. Some benthic fish are capable of burying themselves, such as
flatfishThe flatfish are an order of ray-finned fish, also called the Heterosomata, sometimes classified as a suborder of Perciformes. The name means "side-swimmers" in Greek. In many species both eyes lie on one side of the head, one or the other migrating through and around the head during development...
or
stingrayThe stingrays are a family—Dasyatidae—of rays, cartilaginous fishes related to sharks. They are common in coastal tropical and subtropical marine waters throughout the world, but the family also includes species found in warmer temperate oceans such as Dasyatis thetidis, and species entirely...
.
FlatfishThe flatfish are an order of ray-finned fish, also called the Heterosomata, sometimes classified as a suborder of Perciformes. The name means "side-swimmers" in Greek. In many species both eyes lie on one side of the head, one or the other migrating through and around the head during development...
are an
orderIn scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
of ray-finned benthic fishes which lie flat on the ocean floor. Examples are
flounderFlounder is an ocean-dwelling flatfish species that is located off the Canadian and U.S. east coast of the Northern Atlantic, and the Pacific Ocean, in coastal lagoons and estuaries.-Taxonomy:...
,
soleSole is a type of flatfish of varying families. Generally speaking, they are the members of the family Soleidae, but, outside Europe, the name 'sole' is also applied to various other similar flatfish, especially other members of the sole suborder Soleoidei as well as members of the flounder family...
,
turbotTurbot are flatfish native to marine or brackish waters of the North Atlantic, Black Sea, Baltic Sea and the Mediterranean Sea.-Origin:...
,
plaicePlaice is the common name of four species of flatfishes:* Alaska plaice, Pleuronectes quadrituberculatus* American plaice, Hippoglossoides platessoides* European plaice, Pleuronectes platessa* Scale-eye plaice, Acanthopsetta nadeshnyi...
, and
halibutA halibut is a type of flatfish from the family of the right-eye flounders . This name is derived from haly and butt , alleged to be called so from being commonly eaten on holy-days...
. The adult fish of many species have both eyes on one side of the head. When the fish hatches, one eye is located on each side of its head. But as the fish grows from the larval stage, one eye migrates to the other side of the body as a process of
metamorphosisMetamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation...
. The flatfish then changes its habits, and camouflages itself by lying on the bottom of the ocean floor with both eyes facing upwards. The side on which the eye migrates depends on the species, so some species end up with both eyes on their left side, and others on the right.
Flounder ambush their prey, feeding at soft muddy area of the sea bottom, near bridge piles, docks, artificial and coral reefs. Their diet consists mainly of fish spawn,
crustaceanCrustaceans are a very large group of arthropods, comprising almost 52,000 described species , and are usually treated as a subphylum . They include various familiar animals, such as crabs, lobsters, crayfish, shrimp, krill and barnacles...
s,
polychaeteThe 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 and small fish.
The
great hammerheadThe great hammerhead, Sphyrna mokarran, is the largest species of hammerhead shark, family Sphyrnidae, attaining a maximum length of 6.1 m . It is found in tropical and warm temperate waters worldwide, inhabiting coastal areas and the continental shelf...
swings its head in broad angles over the sea floor to pick up the electrical signatures of stingrays buried in the sand. It then uses its "hammer" to pin down the stingray.
Some fishes don't fit into the above classification. For example, the family of nearly blind spiderfishes, common and widely distributed, feed on benthopelagic zooplankton. Yet they are strictly benthic fish, since they stay in contact with the bottom. Their fins have long rays they use to "stand" on the bottom while they face the current and grab zooplankton as it passes by.
The bodies of benthic fish are adapted for ongoing contact with the sea floor. Swimbladders are usually absent or reduced, and the bodies are usually flattened in one way or another. Following Moyle and Cech (2004) they can be divided into five overlapping body shapes:
| Body types of benthic fish |
| Bottom rovers |
|
Bottom rovers "have a rover-predator-like body , except that the head tends to be flattened, the back humped, and the pectoral fins enlarged. North American catfishLoricariidae is the largest family of catfish , with almost 700 species and new species being described each year. Loricariids originate from fresh water habitats of Costa Rica, Panama, and tropical and subtropical South America. These fish are noted for the bony plates covering their bodies and...
with large mouths at the end of the snout, small armoured catfishLoricariidae is the largest family of catfish , with almost 700 species and new species being described each year. Loricariids originate from fresh water habitats of Costa Rica, Panama, and tropical and subtropical South America. These fish are noted for the bony plates covering their bodies and...
with small mouths beneath the snout, and sturgeonSturgeon is the common name used for some 26 species of fish in the family Acipenseridae, including the genera Acipenser, Huso, Scaphirhynchus and Pseudoscaphirhynchus. The term includes over 20 species commonly referred to as sturgeon and several closely related species that have distinct common...
s, with fleshy protusible lips located well below the snout that are used to suck plant and animal matter off the bottom." |
| Bottom clingers |
|
Bottom clingers "are mainly small fish with flattened heads, large pectoral fins, and structures (usually modified pelvic fins) that enable them to adhere to the bottom. Such structures are handy in swift streams, or intertidal areas with strong currents. The simplest arrangement is possessed by sculpinA Sculpin is a fish that belongs to the Order Scorpaeniformes, Suborder Cottoidei and Superfamily Cottoidea that contains 11 families, 149 genera, and 756 species according to though these totals will likely change as more molecular work is done...
s, which use their small, closely spaced pelvic fins, as antiskid devices. However, other families of fishes, such as gobiesThe gobies form the family Gobiidae, which is one of the largest families of fish, with more than 2,000 species in more than 200 genera. Most are relatively small, typically less than 10 cm in length...
, and clingfishes have evolved suction cups." |
| Bottom hiders |
|
Bottom hiders "are similar in many ways to bottom clingers. but they lack the clinging devices and tend to have more elongate bodies and smaller heads. These forms usually live under rocks or in crevices or lie quietly on the bottom in still waters. The darters Darter may refer to:Animals* Darters or snakebirds, birds of the genus Anhinga* Fishes of several Percidae genera:** Ammocrypta ** Etheostoma ** Percina...
of North American streams are in the category, as are many blennies." |
| Flatfish |
|
Flatfish "have the most extreme morphologies of the bottom fish. FlounderFlounder is an ocean-dwelling flatfish species that is located off the Canadian and U.S. east coast of the Northern Atlantic, and the Pacific Ocean, in coastal lagoons and estuaries.-Taxonomy:...
s are essentially deep-bodied fish which live with one side on the bottom. In these fish, the eye on the downward side migrates during development to the upward side, and the mouth often assumes a peculiar twist to enable bottom feeding. In contrast, skateSkates are cartilaginous fish belonging to the family Rajidae in the superorder Batoidea of rays. There are more than 200 described species in 27 genera.-Description and habitat:...
s and rayRay may refer to:*Batoidea , a superorder of cartilaginous fishes**Rajiformes, "True rays" and skates*Ray , idealized narrow beam of light*Ray or half-line in geometry or physics...
s are flattened dorsoventrally, and mostly move about by flapping their extremely large pectoral fins. Not only is the mouth completely ventral on these fish, the main water intakes for respiration (the spiracleSpiracles are small openings on the surface of some animals that usually lead to respiratory systems.In elasmobranchs , a spiracle is found behind each eye, and is often used to pump water through the gills while the animal is at rest .-Spiracles in insects:Insects and some more advanced spiders...
s) are located on the top of the head." |
| Rattails |
|
Rattail-shaped fish "have bodies that begin with large pointy-snouted heads and large pectoral fins and end and in long pointed rat-like tails. These fish are almost all bottom-dwelling (benthic) inhabitants of the deep sea, but exactly why this peculiar morphology is so popularamong them is poorly understood. The fishes live by scavenging and and preying on benthic invertebrates. Examples are thegrenadiers, brotulaBrotulas are a family, Bythitidae, of ophidiiform fishes, also known as viviparous brotulas as they bear live young. They are found in tropical and subtropical waters throughout the world...
s (pictured), and chimaeraChimaeras are cartilaginous fish in the order Chimaeriformes, known informally as ghost sharks, ratfish , or rabbitfishes...
s." |
Benthopelagic fish
Benthopelagic fish inhabit the water just above the bottom, feeding on
benthosBenthos are the organisms which live on, in, or near the seabed, also known as the benthic zone. They live in or near marine sedimentary environments, from tidal pools along the foreshore, out to the continental shelf, and then down to the abyssal depths....
and
zooplanktonZooplankton are the heterotrophic type of plankton. Plankton are organisms drifting in the water column of oceans, seas, and bodies of fresh water. The name of zooplankton is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
. Most dermersal fish are benthopelagic.
Deep sea benthopelagic teleosts all have swimbladders. The dominate species,
rattailGrenadiers or rattails are generally large, brown to black gadiform marine fish of the family Macrouridae...
s and cusk eels, have considerable biomass. Other species include deep sea
codCod is the common name for the genus Gadus, belonging to the family Gadidae, and is also used in the common name for various other fishes. Cod is a popular food with a mild flavor, low fat content and a dense, flaky white flesh. Cod livers are processed to make cod liver oil, an important source of...
s (
moridsMoridae is a family of cod-like fishes, known as codlings, hakelings, and moras.Morids are marine fishes found throughout the world, and may be found at depths of up to , although most prefer shallower waters...
), deep sea eels,
halosaurHalosaurs are eel-shaped fishes found only at great ocean depths. As the family Halosauridae, halosaurs are one of two families within the order Notacanthiformes; the other being the deep-sea spiny eels. Halosaurs are thought to have a worldwide distribution, with some seventeen species in three...
s and
notacanthNotacanthiformes is an order of deep-sea ray-finned fishes, consisting of the families Halosauridae and Notacanthidae The order is of relatively recent vintage; Fishes of the World lists it as a suborder Notacanthoidei of Albuliformes...
s.
Benthopelagic sharks, like the deep sea
squaloid sharksSqualiformes is an order of sharks that includes about 80 species in seven families.Members of the order have two dorsal fins, which usually possess spines, no anal fin or nictitating membrane, and five gill slits. In most other respects, however, they are quite variable in form and size...
, achieve neutrally buoyancy with the use of large
oil-filled liversShark liver oil is obtained from sharks that are caught for food purposes and are living in cold, deep oceans. The liver oil from sharks has been used by fishermen for centuries as a folk remedy for general health. It is purportedly useful for healing wounds, sores, irritations of the respiratory...
. Sharks adapt well to fairly high pressures. They can often be found on slopes down to about 2000 metres, scavenging on food falls such as dead whales. However, the energy demands of sharks are high, since they need to swim constantly and maintain a large amount of oil for buoyancy. These energy needs cannot be met in the extreme oligotrophic conditions that occur at great depths.
Shallow water stingrays are benthic, and can lie on the bottom because of their negative buoyancy. Deep sea stingrays are benthopelagic, and like the squaloids have very large livers which give them neutral buoyancy.
Benthopelagic fish can be divided into flabby or robust body types. Flabby benthopelagic fishes are like bathypelagic fishes; they have a reduced body mass, and low metabolic rates, expending minimal energy as they lie and wait to
ambushAmbush predators or sit-and-wait predators are carnivorous animals that capture prey by stealth or cunning, not by speed or necessarily by strength. These organisms usually hide motionless and wait for prey to come within striking distance. They are often camouflaged, and may be solitary...
prey. An example of a flabby fish is the cusk-eel
Acanthonus armatus, a predator with a huge head and a body that is 90 percent water. This fish has the largest ears (
otolithAn otolith, , also called statoconium or otoconium is a structure in the saccule or utricle of the inner ear, specifically in the vestibular labyrinth. The saccule and utricle, in turn, together make the otolith organs. They are sensitive to gravity and linear acceleration...
s) and the smallest brain in relation to its body size of all known vertebrates.
Deepwater benthopelagic fish are robust, muscular swimmers that actively cruise the bottom searching for prey. They often live around features, such as
seamountA seamount is a mountain rising from the ocean seafloor that does not reach to the water's surface , and thus is not an island. These are typically formed from extinct volcanoes, that rise abruptly and are usually found rising from a seafloor of 1,000–4,000 meters depth...
s, which have strong currents. Commercial examples are the
orange roughyThe orange roughy, red roughy, or deep sea perch, Hoplostethus atlanticus, is a relatively large deep-sea fish belonging to the slimehead family . The Marine Conservation Society has categorized orange roughy as vulnerable to exploitation...
and
Patagonian toothfishThe Patagonian toothfish, species Dissostichus eleginoides, is a fish found in the cold, temperate waters of the Southern Atlantic, Southern Pacific, Indian, and Southern Oceans on seamounts and continental shelves around most sub‐Antarctic islands.A close relative, the Antarctic toothfish The...
.
Habitats
The edge of the
continental shelfThe continental shelf is the extended perimeter of each continent and associated coastal plain, and was part of the continent during the glacial periods, but is undersea during interglacial periods such as the current epoch by relatively shallow seas and gulfs. The continental rise is below the...
marks the boundary where the shelf gives way to, and then gradually drops into abyssal depths. This edge marks the boundary between coastal, relatively shallow, benthic habitats, and the deep benthic habitats. Coastal demersal fishes live on the bottom of inshore waters, such as bays and estuaries, and further out, on the floor of the
continental shelfThe continental shelf is the extended perimeter of each continent and associated coastal plain, and was part of the continent during the glacial periods, but is undersea during interglacial periods such as the current epoch by relatively shallow seas and gulfs. The continental rise is below the...
. Deep water demersal fish live beyond this edge, mostly down the continental slopes and along the continental rises which drop to the
abyssal plainAbyssal plains are flat or very gently sloping areas of the deep ocean basin floor. They are among the Earth's flattest and smoothest regions and the least explored. Abyssal plains cover approximately 40% of the ocean floor and reach depths between...
s. This is the
continental marginThe continental margin is the zone of the ocean floor that separates the thin oceanic crust from thick continental crust. Continental margins constitute about 28% of the oceanic area....
, constituting about 28% of the total oceanic area. Other deep sea demersal fish can also be found around
seamountA seamount is a mountain rising from the ocean seafloor that does not reach to the water's surface , and thus is not an island. These are typically formed from extinct volcanoes, that rise abruptly and are usually found rising from a seafloor of 1,000–4,000 meters depth...
s and islands.
The term
bathydemersal fish is sometimes used instead of "deep water demersal fish".
Bathydemersal refers to demersal fish which live at depths greater than 200 metres.
The term
epibenthic is also used to refer to organism that live on top of the ocean floor, as opposed to those that burrow into the seafloor substrate. However the terms
mesodemersal,
epidemersal,
mesobenthic and
bathybenthic are not used.
Coastal
Coastal demersal fish are found on or near the seabed of coastal waters between the shoreline and the edge of the
continental shelfThe continental shelf is the extended perimeter of each continent and associated coastal plain, and was part of the continent during the glacial periods, but is undersea during interglacial periods such as the current epoch by relatively shallow seas and gulfs. The continental rise is below the...
, where the shelf drops into the deep ocean. Since the continental shelf is generally less than 200 metres deep, this means that coastal waters are generally epipelagic. The term includes demersal
reef fishReef fish are fish which live amongst or in close relation to coral reefs. Marine fishes are at their most diverse in coral reef ecosystems. However, increasing pollution and destructive fishing practices are threatening the survival of the coral reefs and the associated reef fish.-References:*...
and demersal fish that inhabit estuaries,
inletAn inlet is a narrow body of water between islands or leading inland from a larger body of water, often leading to an enclosed body of water, such as a sound, bay, lagoon or marsh. In sea coasts an inlet usually refers to the actual connection between a bay and the ocean and is often called an...
s and
bayA bay is an area of water mostly surrounded or otherwise demarcated by land. Bays generally have calmer waters than the surrounding sea, due to the surrounding land blocking some waves and often reducing winds....
s.
Young mangrove jacks, a sought after eating and sport fish, dwell in estuaries around
mangroveMangroves are trees and shrubs that grow in saline coastal habitats in the tropics and subtropics – mainly between latitudes N and S. The saline conditions tolerated by various species range from brackish water, through pure seawater , to water of over twice the salinity of ocean seawater,...
roots, fallen trees, rock walls, and any other snag areas where smaller prey reside for protection. When they mature, they migrate into open waters, sometimes hundreds of kilometres from the coast to spawn.
StargazerThe stargazers are a family Uranoscopidae of perciform fish that have eyes on top of their heads . The family includes about 50 species in 8 genera, all marine and found worldwide in shallow waters....
s are found worldwide in shallow waters. They have eyes on top of their heads and a large upward-facing mouth. They bury themselves in sand, and leap upwards to ambush benthopelagic fish and
invertebrateAn invertebrate is an animal without a vertebral column. The group includes 95% of all animal species — all animals except those in the Chordate subphylum Vertebrata ....
s that pass overhead. Some species have a worm-shaped lure growing out of the floor of the mouth, which they wiggle to attract prey. Stargazers are venomous and can deliver
electric shockAn electric shock can occur upon contact of a human body with any source of voltage high enough to cause sufficient current through the muscles or hair. The minimum current a human can feel is thought to be about 1 milliampere ....
s. They have been called "the meanest things in creation."
Other examples of coastal demersal fish are
codCod is the common name for the genus Gadus, belonging to the family Gadidae, and is also used in the common name for various other fishes. Cod is a popular food with a mild flavor, low fat content and a dense, flaky white flesh. Cod livers are processed to make cod liver oil, an important source of...
,
plaicePlaice is the common name of four species of flatfishes:* Alaska plaice, Pleuronectes quadrituberculatus* American plaice, Hippoglossoides platessoides* European plaice, Pleuronectes platessa* Scale-eye plaice, Acanthopsetta nadeshnyi...
,
monkfishMonkfish is the English name of a number of types of fish in the northwest Atlantic, most notably the species of the anglerfish genus Lophius and the angelshark genus Squatina...
and
soleSole is a type of flatfish of varying families. Generally speaking, they are the members of the family Soleidae, but, outside Europe, the name 'sole' is also applied to various other similar flatfish, especially other members of the sole suborder Soleoidei as well as members of the flounder family...
.
Deep water
Deep water demersal fish occupy the
benthic regionsThe benthic zone is the ecological region at the lowest level of a body of water such as an ocean or a lake, including the sediment surface and some sub-surface layers. Organisms living in this zone are called benthos. They generally live in close relationship with the substrate bottom; many such...
beyond the continental margins.
On the continental slope, demersal fishes are common. They are more diverse than coastal demersal fish, since there is more habitat diversity. Further out are the
abyssal plainAbyssal plains are flat or very gently sloping areas of the deep ocean basin floor. They are among the Earth's flattest and smoothest regions and the least explored. Abyssal plains cover approximately 40% of the ocean floor and reach depths between...
s. These flat, featureless regions occupy about 40 percent of the ocean floor. They are covered with
sedimentPelagic sediments, also known as marine sediments, are those that accumulate in the abyssal plain of the deep ocean, far away from terrestrial sources that provide terrigenous sediments; the latter are primarily limited to the continental shelf, and at some point were probably deposited by rivers...
but largely devoid of benthic life (
benthosBenthos are the organisms which live on, in, or near the seabed, also known as the benthic zone. They live in or near marine sedimentary environments, from tidal pools along the foreshore, out to the continental shelf, and then down to the abyssal depths....
). Deep sea benthic fishes are more likely to associate with canyons or rock outcroppings among the plains, where invertebrate communities are established. Undersea mountains (
seamountA seamount is a mountain rising from the ocean seafloor that does not reach to the water's surface , and thus is not an island. These are typically formed from extinct volcanoes, that rise abruptly and are usually found rising from a seafloor of 1,000–4,000 meters depth...
s) can intercept deep sea currents, and cause productive upwellings which support benthic fish. Undersea mountain ranges can separate underwater regions into different ecosystems.
RattailGrenadiers or rattails are generally large, brown to black gadiform marine fish of the family Macrouridae...
s and
brotulaBrotulas are a family, Bythitidae, of ophidiiform fishes, also known as viviparous brotulas as they bear live young. They are found in tropical and subtropical waters throughout the world...
s are common, and other well established families are
eelTrue eels are an order of fish, which consists of four suborders, 19 families, 110 genera and approximately 600 species. Most eels are predators...
s,
eelpoutThe eelpouts are the ray-finned fish family Zoarcidae. As the common name suggests, they are somewhat eel-like in appearance, with elongate bodies, and the dorsal and anal fins continuous with the caudal fin. All of the approximately 220 species are marine, mostly bottom-dwelling, some at great...
s,
hagfishHagfish are marine craniates of the class Myxini, also known as Hyperotreti. Myxini is the only class in the clade Craniata that does not also belong to the subphylum Vertebrata...
es,
greeneyeGreeneyes are deep-sea aulopiform marine fishes in the small family Chlorophthalmidae. Thought to have a circumglobal distribution in tropical and temperate waters, the family contains just 18 species in two genera...
s,
batfishBatfish is a name given to several fishes:* Malthe vespertilio of the Atlantic coast.* The flying gurnard of the Atlantic .* The California batfish or sting ray ....
es and lumpfishes.
The bodies of deep water demersal fishes are muscular with well developed organs. In this way they are closer to mesopelagic fishes than bathypelagic fishes. In other ways, they are more variable.
PhotophoreA photophore is a light-emitting organ which appears as luminous spots on various marine animals, including fish and cephalopods. The organ can be simple, or as complex as the human eye; equipped with lenses, shutters, color filters and reflectors...
s are usually absent, eyes and swimbladders range from absent to well developed. They vary in size, and larger species, greater than one metre, are not uncommon.
Deep sea demersal fish are usually long and narrow. Many are
eelTrue eels are an order of fish, which consists of four suborders, 19 families, 110 genera and approximately 600 species. Most eels are predators...
s or shaped like eels. This may be because long bodies have long
lateral lineIn aquatic organisms , the lateral line is a sense organ used to detect movement and vibration in the surrounding water. Lateral lines are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail...
s. Lateral lines detect low-frequency sounds, and some demersal fishes have muscles that drum such sounds to attract mates. Smell is also important, as indicated by the rapidity with which demersal fish find traps baited with
bait fishBait fish are small fish caught for use as bait to attract large predatory fish, particularly game fish. Species used are typically those that are common and breed rapidly, making them easy to catch and in regular supply. Examples of marine bait fish are anchovies, halfbeaks such as ballyhoo, and...
.
The main diet of deep sea demersal fish is
invertebrateAn invertebrate is an animal without a vertebral column. The group includes 95% of all animal species — all animals except those in the Chordate subphylum Vertebrata ....
s of the deep sea
benthosBenthos are the organisms which live on, in, or near the seabed, also known as the benthic zone. They live in or near marine sedimentary environments, from tidal pools along the foreshore, out to the continental shelf, and then down to the abyssal depths....
and
carrionCarrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters, or scavengers, include Hyenas, Vultures, Canadian Opossum, Tasmanian Devils, Black Bears, Komodo Dragons, Bald Eagles, Raccoons,...
. Smell, touch and lateral line sensitivities seem to be the main sensory devices for locating these.
Like coastal demersal fish, deep sea demersal fish can be divided into benthic fish and benthopelagic fish, where the benthic fish are negatively buoyant and benthopelagic fish are neutrally buoyant.
The availability of plankton for food diminishes rapidly with depth. At 1000 metres, the biomass of plankton is typically about 1 percent of that at the surface, and at 5000 metres about 0.01 percent. Given there is no sunlight, energy enters deep water zones as organic matter. There are three main ways this happens. Firstly, organic matter can move into the zone from the continental landmass, for example, through currents that carry the matter down rivers, then plume along the continental shelf and finally spill down the continental slope. Other matter enters as particulate matter raining down from the overhead water column in the form of
marine snowIn the deep ocean, marine snow is a continuous shower of mostly organic detritus falling from the upper layers of the water column. Its origin lies in activities within the productive photic zone. Consequently, the prevalence of marine snow changes with seasonal fluctuations in photosynthetic...
, or as sinking overhead plant material such as
eelgrassEelgrass may refer to:* Zostera, marine eelgrass* Vallisneria, freshwater eelgrass...
, or as "large particles" such as dead fish and whales sinking to the bottom. A third way energy can arrive is through fish, such as vertically migrating mesopelagic fishes that can enter into the demersal zone as they ascend or descend. The demersal fish and invertebrates consume organic matter that does arrive, break it down and recycle it. A consequence of these energy delivery mechanisms is that the abundance of demersal fish and invertebrates gradually decrease as the distance from continental shorelines increases.
Although deep water demersal fish species are not generally picky about what they eat, there is still some degree of specialisation. For example, different fish have different mouth sizes, which determines the size of the prey they can handle. Some feed mostly on benthopelagic organisms. Others fed mostly on epifauna (invertebrates on top of the seafloor surface, also called
epibenthos), or alternatively on infauna (invertebrates that burrow into the seafloor substrate). Infauna feeders can have considerable sediment in their stomachs. Scavengers, such as
snubnosed eelThe snubnosed eel, Simenchelys parasitica, also known as the pug-nosed eel, slime eel, or snub-nose parasitic eel, is a species of deep-sea eel and the only member of its genus. Some authors classify it as the sole member of the subfamily Simenchelyinae of the family Synaphobranchidae, or...
s and
hagfishHagfish are marine craniates of the class Myxini, also known as Hyperotreti. Myxini is the only class in the clade Craniata that does not also belong to the subphylum Vertebrata...
, also eat infauna as a secondary food source.
Some feed on carrion. Cameras show that when a dead fish is placed on the bottom, vertebrate and invertebrate scavengers appear very quickly. If the fish is large, some scavengers burrow in and eat it from the inside out. Some fish, such as grenadiers, also appear and start feeding on the scavenging inverebrates and amphipods. Other specialization is based on depth distribution. Some of the more abundant upper continental slope fish species, such as
cutthroat eelCutthroat eels are a family, Synaphobranchidae, of eels, the only member of the suborder Synaphobranchoidei. They are found worldwide in temperate and tropical seas....
and
longfinned hakePhycidae is a family of hakes in the order Gadiformes. They are native to the Atlantic Ocean, but the juveniles of some species enter estuaries.Joseph Nelson classifies this family as the subfamily Phycinae of the cod family, Gadidae.-Species:...
, mainly feed on on epipelagic fish. But generally, the most abundant deep water demersal fish species feed on invertebrates.
At great depths, food scarcity and extreme pressure limits the ability of fish to survive. The deepest point of the ocean is about 11,000 metres. Bathypelagic fishes are not normally found below 3,000 metres. It may be that extreme pressures interfere with essential enzyme functions.
The deepest-living fish known, the strictly benthic
Abyssobrotula galatheaeAbyssobrotula galatheae is a species of cusk eel in the family Ophidiidae, and the only species in its genus. It is the deepest-living fish known; one specimen, trawled from a depth of 8,370 m in the Puerto Rico Trench in 1970, holds the record for the deepest fish ever captured...
, eel-like and blind, feeds on benthic invertebrates. A living example was trawled from the bottom of the
Puerto Rico TrenchThe Puerto Rico Trench is an oceanic trench located on the boundary between the Caribbean Sea and the Atlantic Ocean. The trench is associated with a complex transition between the subduction zone to the south along the Lesser Antilles island arc and the major transform fault zone or plate boundary...
in 1970 from a depth of 8,370 metres (27,453 ft).
In 2008, a shoal of 17
hadal snailfishThe hadal snailfish, Pseudoliparis amblystomopsis is a species of snailfish, described by Anatoly Petrovich Andriashev in 1955.In October 2008, a team of researchers from the University of Aberdeen's Oceanlab and the University of Tokyo's Ocean Research Institute discovered a shoal of P....
, a species of deep water
snailfishSnailfishes are scorpaeniform marine fish of the family Liparidae. Widely distributed from the Arctic to Antarctic Oceans including the northern Pacific, the snailfish family contains approximately 23 genera and 195 species. They are closely related to the sculpins of the Cottidae family and the...
, was filmed by a UK-Japan team using remote operated landers at depths of 7.7 km (4.8 miles) in the
Japan TrenchThe Japan Trench is an oceanic trench, a part of the Pacific Ring of Fire, in the floor of the northern Pacific Ocean off northeast Japan. It extends from the Kuril Islands to the Bonin Islands and is at its deepest. It is an extension of the Kuril-Kamchatka Trench to the north and the...
in the Pacific. The fish were 30 centimetres long (12 in), and were darting about, using vibration sensors on their nose to catch shrimps. The team also reported that the appearance of the fish, unlike that of most deep sea fish, was surprisingly "cute", and that they were surprised by how active the fish were at these depths.
Demersal fisheries
Most demersal fish of commercial or recreational interest are coastal, confined to the upper 200 metres. Commercially important demersal food fish species include
flatfishThe flatfish are an order of ray-finned fish, also called the Heterosomata, sometimes classified as a suborder of Perciformes. The name means "side-swimmers" in Greek. In many species both eyes lie on one side of the head, one or the other migrating through and around the head during development...
, such as
flounderFlounder is an ocean-dwelling flatfish species that is located off the Canadian and U.S. east coast of the Northern Atlantic, and the Pacific Ocean, in coastal lagoons and estuaries.-Taxonomy:...
,
soleSole is a type of flatfish of varying families. Generally speaking, they are the members of the family Soleidae, but, outside Europe, the name 'sole' is also applied to various other similar flatfish, especially other members of the sole suborder Soleoidei as well as members of the flounder family...
,
turbotTurbot are flatfish native to marine or brackish waters of the North Atlantic, Black Sea, Baltic Sea and the Mediterranean Sea.-Origin:...
,
plaicePlaice is the common name of four species of flatfishes:* Alaska plaice, Pleuronectes quadrituberculatus* American plaice, Hippoglossoides platessoides* European plaice, Pleuronectes platessa* Scale-eye plaice, Acanthopsetta nadeshnyi...
, and
halibutA halibut is a type of flatfish from the family of the right-eye flounders . This name is derived from haly and butt , alleged to be called so from being commonly eaten on holy-days...
. Also important are
codCod is the common name for the genus Gadus, belonging to the family Gadidae, and is also used in the common name for various other fishes. Cod is a popular food with a mild flavor, low fat content and a dense, flaky white flesh. Cod livers are processed to make cod liver oil, an important source of...
,
hakeThe term hake refers to fish in either of:* family Gadidae * family Merlucciidae .An old European source mentions a hake that was transplanted from the coast of Ireland to Cape Cod...
,
redfishRedfish is a common name for several species of fish. It is most commonly applied to members of the deep-sea genus Sebastes, or the reef dwelling snappers, Lutjanus. It is also applied to the slimeheads or roughies , and the alfonsinos ....
,
haddockThe haddock or offshore hake is a marine fish distributed on both sides of the North Atlantic. Haddock is a popular food fish, widely fished commercially....
,
bassBass is a name shared by many different species of popular gamefish. The term encompasses both freshwater and marine species. All belong to the large order Perciformes, or perch-like fishes, and in fact the word bass comes from Middle English bars, meaning "perch." The collective name for a group...
,
congerConger is a genus of marine congrid eels. It includes some of the largest types of eels, ranging up to 3 m in length."Conger" or "Conger eel" is also the common name of a number of species, including members of this genus.-Species:...
s,
sharkSharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago, before the time of the dinosaurs....
s,
rayRay may refer to:*Batoidea , a superorder of cartilaginous fishes**Rajiformes, "True rays" and skates*Ray , idealized narrow beam of light*Ray or half-line in geometry or physics...
s and
chimaeraChimaeras are cartilaginous fish in the order Chimaeriformes, known informally as ghost sharks, ratfish , or rabbitfishes...
s.
The following table shows the world capture production of some groups of demersal species in tonnes.
| Capture production by groups of species in tonnes |
| Group |
1999 |
2000 |
2001 |
2002 |
2003 |
2004 |
2005 |
Flounders, halibutA halibut is a type of flatfish from the family of the right-eye flounders . This name is derived from haly and butt , alleged to be called so from being commonly eaten on holy-days...
s, soleSole may refer to:* Sole , the bottom of the foot* Sole , the bottom supporting member of the shoe-In business:* Sole proprietorship, a business which legally has no separate existence from its owner...
s |
956 926 |
1 009 253 |
948 427 |
915 177 |
917 326 |
862 162 |
900 012 |
CodCod is the common name for the genus Gadus, belonging to the family Gadidae, and is also used in the common name for various other fishes. Cod is a popular food with a mild flavor, low fat content and a dense, flaky white flesh. Cod livers are processed to make cod liver oil, an important source of...
s, hakeThe term hake refers to fish in either of:* family Gadidae * family Merlucciidae .An old European source mentions a hake that was transplanted from the coast of Ireland to Cape Cod...
s, haddockThe haddock or offshore hake is a marine fish distributed on both sides of the North Atlantic. Haddock is a popular food fish, widely fished commercially....
s |
9 431 141 |
8 695 910 |
9 304 922 |
8 474 044 |
9 385 328 |
9 398 780 |
8 964 873 |
| Miscellaneous demersal fishes |
2 955 849 |
3 033 384 |
3 008 283 |
3 062 222 |
3 059 707 |
3 163 050 |
2 986 081 |
Black sea bassThe black sea bass is an exclusively marine fish. It is a type of Grouper found more commonly in northern than in southern ranges.It inhabits the coasts from Maine to NE Florida and the eastern Gulf of Mexico....
inhabit US coasts from
MaineThe State of Maine is a state in the New England region of the northeastern United States, bordering the Atlantic Ocean to the southeast, New Hampshire to the southwest, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is the northernmost portion of...
to NE
FloridaFlorida is a state located in the southeastern region of the United States, bordering Alabama to the northwest and Georgia to the north. It was the 27th state admitted to the United States...
and the eastern
Gulf of MexicoThe Gulf of Mexico is the ninth largest body of water in the world. Considered a smaller part of the Atlantic Ocean, it is an ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United...
, and are most abundant off the waters of
New YorkNew York is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous. The state is bordered by New Jersey and Pennsylvania to the south, and Connecticut, Massachusetts and Vermont to the east...
. They are found in inshore waters (bays and sounds) and offshore in waters up to a depth of 130 m (425'). They spend most of their time close to the sea floor and are often congregated around bottom formations such as rocks, man-made reefs, wrecks, jetties, piers, and bridge pilings. Black sea bass are sought after recreational and commercial fish, and have been
overfishedOverfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....
.
GrouperGroupers are fish of any of a number of genera in the subfamily Epinephelinae of the family Serranidae, in the order Perciformes.Not all serranids are called groupers; the family also includes the sea basses. The common name grouper is usually given to fish in one of two large genera: Epinephelus...
are often found around reefs. They have stout bodies and large mouths. They are not built for long-distance or fast swimming. They can be quite large, and lengths over a meter and weights up to 100 kg are not uncommon. They swallow prey rather than biting pieces off it. They do not have many teeth on the edges of their jaws, but they have heavy crushing tooth plates inside the
pharynxThe pharynx is the part of the neck and throat situated immediately posterior to the mouth and nasal cavity, and cranial, or superior, to the esophagus, larynx, and trachea.-Functions:...
. They lie in wait, rather than chasing in open water. They are found in areas of hard or consolidated substrate, and use structural features such as ledges, rocks, and coral reefs ( as well as artificial reefs like wrecks and sunken barges) as their habitat.
Their mouth and
gillA gill is an anatomical structure found in many aquatic organisms. It is a respiration organ whose function is the extraction of oxygen from water and the excretion of carbon dioxide...
s form a powerful sucking system that sucks their prey in from a distance. They also use their mouth to dig into sand to form their shelters under big rocks, jetting it out through their gills. Their gill muscles are so powerful that it is nearly impossible to pull them out of their cave if they feel attacked and extend those muscles to lock themselves in. There is some research indicating that roving coral groupers (
Plectropomus pessuliferus) sometimes cooperate with
giant moraysMoray eels are huge cosmopolitan eels of the family Muraenidae. There are approximately 200 species in 15 genera. The typical length of a moray is 1.5 m , with the longest being the slender giant moray, Strophidon sathete, at up to 4 m , and the largest, in terms of total mass being the...
in hunting.
Deepwater benthopelagic fish are robust, muscular swimmers that actively cruise the bottom searching for prey. They often live around features, such as
seamountA seamount is a mountain rising from the ocean seafloor that does not reach to the water's surface , and thus is not an island. These are typically formed from extinct volcanoes, that rise abruptly and are usually found rising from a seafloor of 1,000–4,000 meters depth...
s, which have strong currents. Commercial examples are the
orange roughyThe orange roughy, red roughy, or deep sea perch, Hoplostethus atlanticus, is a relatively large deep-sea fish belonging to the slimehead family . The Marine Conservation Society has categorized orange roughy as vulnerable to exploitation...
and
Patagonian toothfishThe Patagonian toothfish, species Dissostichus eleginoides, is a fish found in the cold, temperate waters of the Southern Atlantic, Southern Pacific, Indian, and Southern Oceans on seamounts and continental shelves around most sub‐Antarctic islands.A close relative, the Antarctic toothfish The...
. Because these fish were once abundant, and because their robust bodies are good to eat, these fish have been commercially harvested.
Conservation status
Major demersal fishery species in the
North SeaThe North Sea is a marginal, epeiric sea on the European continental shelf. The Dover Strait and the English Channel in the south and the Norwegian Sea in the north connect it to the Atlantic Ocean. It is more than long and wide, with an area of around...
such as
codCod is the common name for the genus Gadus, belonging to the family Gadidae, and is also used in the common name for various other fishes. Cod is a popular food with a mild flavor, low fat content and a dense, flaky white flesh. Cod livers are processed to make cod liver oil, an important source of...
,
plaicePlaice is the common name of four species of flatfishes:* Alaska plaice, Pleuronectes quadrituberculatus* American plaice, Hippoglossoides platessoides* European plaice, Pleuronectes platessa* Scale-eye plaice, Acanthopsetta nadeshnyi...
,
monkfishMonkfish is the English name of a number of types of fish in the northwest Atlantic, most notably the species of the anglerfish genus Lophius and the angelshark genus Squatina...
and
soleSole is a type of flatfish of varying families. Generally speaking, they are the members of the family Soleidae, but, outside Europe, the name 'sole' is also applied to various other similar flatfish, especially other members of the sole suborder Soleoidei as well as members of the flounder family...
, are listed by the
ICESIces may refer to:*Ices or frozen desserts, particularly within the United Kingdom*Ices or frozen volatiles in the context of astronomy and planetary science*Ices, the phases of iceICES may stand for:...
as "outside safe biological limits."
- The True Sole solea solea is sufficiently broadly distributed that it is not considered a threatened species; however, overfishing
Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....
in Europe has produced severely diminished populations, with declining catches in many regions. For example, the western English ChannelThe English Channel is an arm of the Atlantic Ocean that separates England from northern France, and joins the North Sea to the Atlantic. It is about long and varies in width from at its widest, to only in the Strait of Dover...
and Irish SeaThe Irish Sea also known as the Mann Sea or Manx Sea, separates the islands of Ireland and Britain. It is connected to the Atlantic Ocean in the south by St George's Channel, and in the north by the North Channel...
sole fisheries face potential collapse according to data in the UK Biodiversity Action PlanThis article is about a conservation biology topic. For other uses of BAP, see BAP .A Biodiversity Action Plan is an internationally recognized program addressing threatened species and habitats and is designed to protect and restore biological systems. The original impetus for these plans derives...
.
- Sole, along with the other major bottom-feeding fish in the North Sea
The North Sea is a marginal, epeiric sea on the European continental shelf. The Dover Strait and the English Channel in the south and the Norwegian Sea in the north connect it to the Atlantic Ocean. It is more than long and wide, with an area of around...
such as codCod is the common name for the genus Gadus, belonging to the family Gadidae, and is also used in the common name for various other fishes. Cod is a popular food with a mild flavor, low fat content and a dense, flaky white flesh. Cod livers are processed to make cod liver oil, an important source of...
, monkfishMonkfish is the English name of a number of types of fish in the northwest Atlantic, most notably the species of the anglerfish genus Lophius and the angelshark genus Squatina...
, and plaicePlaice is the common name of four species of flatfishes:* Alaska plaice, Pleuronectes quadrituberculatus* American plaice, Hippoglossoides platessoides* European plaice, Pleuronectes platessa* Scale-eye plaice, Acanthopsetta nadeshnyi...
, is listed by the ICESIces may refer to:*Ices or frozen desserts, particularly within the United Kingdom*Ices or frozen volatiles in the context of astronomy and planetary science*Ices, the phases of iceICES may stand for:...
as "outside safe biological limits." Moreover, they are growing less quickly now and are rarely older than six years, although they can reach forty. World stocks of large predatory fish and large ground fish such as sole and flounder were estimated in 2003 to be only about 10% of pre-industrial levels. According to the World Wildlife Fund in 2006, "of the nine sole stocks, seven are overfished with the status of the remaining two unknown." Data is insufficient to assess the remaining stocks; however, landings for all stocks are at or near historical lows."
- World stocks of large predatory fish and large ground fish such as sole
Sole is a type of flatfish of varying families. Generally speaking, they are the members of the family Soleidae, but, outside Europe, the name 'sole' is also applied to various other similar flatfish, especially other members of the sole suborder Soleoidei as well as members of the flounder family...
and flounder were estimated in 2003 to be only about 10% of pre-industrial levels, largely due to overfishing. Most overfishing is due to the extensive activities of the fishing industry. Current research indicate that the flounder population could be as low as 15 million due to heavy overfishing and industrial pollution along the Gulf of Mexico surrounding the coast of Texas.
- Seafood Watch
Seafood Watch is one of the best known sustainable seafood advisory lists, and has influenced similar programs around the world. It is a program designed to raise consumer awareness about the importance of buying seafood from sustainable sources...
have placed on their list of seafood that sustainabilitySustainability, in a broad sense, is the capacity to endure. In ecology, the word describes how biological systems remain diverse and productive over time...
-minded consumers should avoid the following demersal fish: sturgeonSturgeon is the common name used for some 26 species of fish in the family Acipenseridae, including the genera Acipenser, Huso, Scaphirhynchus and Pseudoscaphirhynchus. The term includes over 20 species commonly referred to as sturgeon and several closely related species that have distinct common...
(imported wild), Chilean seabass, codCod is the common name for the genus Gadus, belonging to the family Gadidae, and is also used in the common name for various other fishes. Cod is a popular food with a mild flavor, low fat content and a dense, flaky white flesh. Cod livers are processed to make cod liver oil, an important source of...
(Atlantic, imported Pacific) , flounderFlounder is an ocean-dwelling flatfish species that is located off the Canadian and U.S. east coast of the Northern Atlantic, and the Pacific Ocean, in coastal lagoons and estuaries.-Taxonomy:...
(Atlantic), halibutA halibut is a type of flatfish from the family of the right-eye flounders . This name is derived from haly and butt , alleged to be called so from being commonly eaten on holy-days...
(Atlantic), soleSole is a type of flatfish of varying families. Generally speaking, they are the members of the family Soleidae, but, outside Europe, the name 'sole' is also applied to various other similar flatfish, especially other members of the sole suborder Soleoidei as well as members of the flounder family...
(Atlantic), (grouperGroupers are fish of any of a number of genera in the subfamily Epinephelinae of the family Serranidae, in the order Perciformes.Not all serranids are called groupers; the family also includes the sea basses. The common name grouper is usually given to fish in one of two large genera: Epinephelus...
, monkfishMonkfish is the English name of a number of types of fish in the northwest Atlantic, most notably the species of the anglerfish genus Lophius and the angelshark genus Squatina...
, orange roughyThe orange roughy, red roughy, or deep sea perch, Hoplostethus atlanticus, is a relatively large deep-sea fish belonging to the slimehead family . The Marine Conservation Society has categorized orange roughy as vulnerable to exploitation...
, demersal sharkSharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago, before the time of the dinosaurs....
, red snapperThe red snapper, Lutjanus campechanus, is a reef fish found in the Gulf of Mexico and the southeastern Atlantic coast of the United States. The original name in Latin American Spanish is Huachinango or Pargo....
and tilapiaTilapia is the common name for nearly a hundred species of cichlid fish from the tilapiine cichlid tribe. Tilapia inhabit a variety of fresh water habitats including shallow streams, ponds, rivers, lakes and estuaries. Most tilapia are omnivorous with a preference for aquatic vegetation and detritus...
(Asia farmed).
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