The snake pipefish (''Entelurus aequoreus'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of pipefish, from the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Syngnathidae, native to the northeastern

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

where they are generally found amongst algae close in to shore. It is the largest species of pipefish recorded in European waters and has spread into arctic waters in the early 2000s.

Description

The snake pipefish has a very long, elongated and slender body which has a smooth skin and rounded cross-section and which is distinguished from other

sympatric In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sh ...

pipefishes by the near lack of bony rings. It has a long head, with a thin dark stripe in its sides, with a long, concave snout and a very small, protractile mouth. The long based dorsal fin has 37-47 short rays while the

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

is minute and there are no

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

s or

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

s. They are pale brown or yellowish-green in colour with each of the 28-31 rings on the body marked out by pale blue rings with dark margins. The opening to the gills has been reduced to a pore in the membrane above the

opercle The operculum is a series of bones found in bony fish and chimaeras that serves as a facial support structure and a protective covering for the gills; it is also used for respiration and feeding. Anatomy The opercular series contains four bon ...

and the gill membranes are fused to the body and the isthmus. They can grow to total lengths of in males and in females, although they are more commonly around and respectively. The juveniles of less than 70 mm in length have membranous pectoral fins which disappear as they mature.

Distribution

The snake pipefish occurs in the north eastern Atlantic from Iceland and Norway to the

Azores ) , motto =( en, "Rather die free than subjected in peace") , anthem= ( en, "Anthem of the Azores") , image_map=Locator_map_of_Azores_in_EU.svg , map_alt=Location of the Azores within the European Union , map_caption=Location of the Azores wi ...

, into the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and from ...

. In the early 2000s it expanded its range northwards as far as

Svalbard Svalbard ( , ), also known as Spitsbergen, or Spitzbergen, is a Norwegian archipelago in the Arctic Ocean. North of mainland Europe, it is about midway between the northern coast of Norway and the North Pole. The islands of the group range ...

and the

Barents Sea The Barents Sea ( , also ; no, Barentshavet, ; russian: Баренцево море, Barentsevo More) is a marginal sea of the Arctic Ocean, located off the northern coasts of Norway and Russia and divided between Norwegian and Russian territo ...

. Abstract It is not found in the Mediterranean Sea.

Habitat and biology

The snake pipefish occurs in more open and deeper water than other species of pipefish, with a depth range of and it lives among kelp and other types of deep water sea weeds, as well as sea grass such as ''

Zostera marina ''Zostera marina'' is a flowering vascular plant species as one of many kinds of seagrass, with this species known primarily by the English name of eelgrass with seawrack much less used, and refers to the plant after breaking loose from the submer ...

'', but some individuals both young and large adults have been caught in

pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or wa ...

waters. Its colour and patterning provides good

camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the ...

in such habitats. The colonisation of the Waddensee sand flats by the invasive Japanese seaweed '' Sargassum muticum'' has facilitated an increase of snake pipefish in that area. They breed in mid summer when the males and females pair up. They are

ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop insi ...

, the female attaches over 1,000 fertilised eggs, each about in diameter, to a layer of sticky mucus in a groove on the male's belly where they remain until they hatch. Following their birth the fry are pelagic until they attain a length of . The adults feed on small crustaceans and larval fish which are caught by being sucked into the mouth. It was noted when the populations of this species increased in the 2000s that some species of sea bird began to feed on the pipefish but found them rather indigestible due to their bony structure. Among those,

auk An auk or alcid is a bird of the family Alcidae in the order Charadriiformes. The alcid family includes the murres, guillemots, auklets, puffins, and murrelets. The word "auk" is derived from Icelandic ''álka'', from Old Norse ''alka'' (a ...

s and terns tried to feed these pipefish to their young as their more normal diet of

sand-eel Sand eel or sandeel is the common name used for a considerable number of species of fish. While they are not true eels, they are eel-like in their appearance and can grow up to in length. Many species are found off the western coasts of Europe ...

s, had declined. However, the pipefish have limited nutritional value compared to the oily-fleshed sand-eels and many chicks choked on their hard, rather indigestible bodies.

Etymology

The generic name ''Entelurus'' is derived from the Greek ''entelès'' which means "complete" and ''oura'' which means "tail" referring to the long tail which stretches out from the anus and his hardly differentiated from the body while the

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

is from the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

''aequoreus'' which means "marine".

References

External links

* {{Taxonbar, from=Q1548395 snake pipefish Fish of the North Atlantic Fish of the North Sea Fauna of the British Isles snake pipefish snake pipefish