The rock gunnel (''Pholis gunnellus''), or butterfish, is a species of marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

belonging to the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Pholidae ''Pholidae'' is a Family (biology), family of marine ray-finned fishes, known as gunnels, in the Scorpaeniformes, scorpaeniform suborder Zoarcoidei. These are fishes of the littoral zone and are mainly found in North Pacific Ocean, with two speci ...

, the gunnels. This species is found in the coastal waters of the North Atlantic Ocean and in the Atlantic part of the Arctic Ocean.

Taxonomy

The rock gunnel was first formally described in 1758 as ''Blennius gunnellus'' in the 10th edition of the ''

Systema Naturae ' (originally in Latin written ' with the Orthographic ligature, ligature æ) is one of the major works of the Sweden, Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the syste ...

'' by

Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

with the type locality given as the Atlantic. In 1777 by the Italian

naturalist Natural history is a domain of inquiry involving organisms, including animals, fungi, and plants, in their natural environment, leaning more towards observational than experimental methods of study. A person who studies natural history is cal ...

Giovanni Antonio Scopoli Giovanni Antonio Scopoli (sometimes Latinisation of names, Latinized as Johannes Antonius Scopolius) (3 June 1723 – 8 May 1788) was an Italians, Italian physician and natural history, naturalist. His biographer Otto Guglia named him the "first ...

proposed 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 ...

Pholis ''Pholis'' is a genus of marine ray-finned fish belonging to the family Pholidae, the gunnels. These fishes are found in shallow coastal waters of the North Pacific, Arctic and North Atlantic Oceans. Taxonomy ''Pholis'' was first proposed as a g ...

'' and Linnaeus's Blennius gunnellus was later designated to be its

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

. 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 ...

''gunnellis'' is a latinisation of an

English English usually refers to: * English language * English people English may also refer to: Culture, language and peoples * ''English'', an adjective for something of, from, or related to England * ''English'', an Amish ter ...

, possibly originating in

Cornwall Cornwall (; or ) is a Ceremonial counties of England, ceremonial county in South West England. It is also one of the Celtic nations and the homeland of the Cornish people. The county is bordered by the Atlantic Ocean to the north and west, ...

, local name for this species, gunnel.

Description

The rock gunnel is often mistaken for an

eel Eels are ray-finned fish belonging to the order Anguilliformes (), which consists of eight suborders, 20 families, 164 genera, and about 1000 species. Eels undergo considerable development from the early larval stage to the eventual adult stage ...

due to its flattened, elongated body. Fully grown adults can reach 30 cm in length. A long dorsal fin spans the body from just behind the head, supported by soft spiny rays. Its anal fin begins roughly midway along the body. The head is rather small with its lower jaw protruding and mouth turned upwards. Coloration is highly variable, ranging from hues of yellow-green to brown to crimson. A row of 9–13 dark spots, each surrounded by a pale ring, lines the dorsal fin.Campbell, A.C. 1984. ''The Country Life Guide to the Seashore and Shallow Seas of Britain and Europe.'' Country Life Books. The butterfish has a maximum published

standard length Fish measurement is the measuring of individual fish and various parts of fish anatomy, their anatomies, for data used in many areas of ichthyology, including Taxonomy (biology), taxonomy and fishery biology. Overall length Standard length (SL) is ...

of .

Distribution and habitat

The rock gunnel is found in the coastal waters of North America and Europe. It ranges from

Labrador Labrador () is a geographic and cultural region within the Canadian province of Newfoundland and Labrador. It is the primarily continental portion of the province and constitutes 71% of the province's area but is home to only 6% of its populatio ...

and

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

Delaware Bay Delaware Bay is the estuary outlet of the Delaware River on the northeast seaboard of the United States, lying between the states of Delaware and New Jersey. It is approximately in area, the bay's freshwater mixes for many miles with the saltw ...

in the West Atlantic, and from the

Kanin Peninsula The Kanin Peninsula () is a large peninsula in Nenets Autonomous Okrug, Russia. Geography It is surrounded by the White Sea to the west and by the Barents Sea to the north and east. Shoyna (also spelled Shoina) is one of the few communities o ...

to the

Bay of Biscay The Bay of Biscay ( ) is a gulf of the northeast Atlantic Ocean located south of the Celtic Sea. It lies along the western coast of France from Point Penmarc'h to the Spanish border, and along the northern coast of Spain, extending westward ...

in the East Atlantic. Within its range it is found from the intertidal zone to depths of over 100 m. The rock gunnel uses habitat sheltered by rocks and

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

both above and below the waterline, likely to protect it from its natural predators, which include seabirds, fish, and marine mammals.

Behavior

The rock gunnel may remain above the waterline at low tide, sheltered beneath rocks and algae, and can breathe air if necessary. They are frequently encountered on rocky shorelines, and splash around noticeably when uncovered. Within its North American range, the rock gunnel disappears from the intertidal during winter, likely to avoid freezing air temperatures. Their diet is made up of small crustaceans,

polychaete Polychaeta () is a paraphyletic class of generally marine Annelid, annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called c ...

s, mollusks and the eggs of fish. The female lays the eggs in a large mass on the seabed and this is closely guarded until the larvae hatch. The butterfish

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' ...

s from November to January, the female laying between 80 and 200 eggs in a ball-like mass placed beneath a stone or in the empty shell of a bivalve.

References

External links

* http://www.luontoportti.com/suomi/en/kalat/rock-gunnel * {{Taxonbar, from=Q640454 Rock gunnel Fish described in 1758 Taxa named by Carl Linnaeus