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

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or hor ...

belonging to 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 ...

Pholidae ''Pholidae'' is a family of marine ray-finned fishes, known as gunnels, in the scorpaeniform suborder Zoarcoidei. These are fishes of the littoral zone and are mainly found in North Pacific Ocean, with two species found in the North Atlantic Ocea ...

, 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 ligature æ) is one of the major works of the Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the system, now known as binomial nomen ...

'' by

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

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

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

proposed the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 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 species that contains the biological type specimen ...

. 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: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ide ...

, possibly originating in

Cornwall Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...

, 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, 19 families, 111 genera, and about 800 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 their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish m ...

of .

Distribution and habitat

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

Labrador , nickname = "The Big Land" , etymology = , subdivision_type = Country , subdivision_name = Canada , subdivision_type1 = Province , subdivision_name1 ...

and

Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is t ...

Delaware Bay Delaware Bay is the estuary outlet of the Delaware River on the northeast seaboard of the United States. It is approximately in area, the bay's freshwater mixes for many miles with the saltwater of the Atlantic Ocean. The bay is bordered inlan ...

in the West Atlantic, and from the

Kanin Peninsula The Kanin Peninsula () is a large peninsula in Nenets Autonomous Okrug, Russia. It is surrounded by the White Sea to the west and by the Barents Sea to the north and east. Shoyna is one of the few communities on the peninsula. Fauna For cetacea ...

to the

Bay of Biscay The Bay of Biscay (), known in Spain as the Gulf of Biscay ( es, Golfo de Vizcaya, eu, Bizkaiko Golkoa), and in France and some border regions as the Gulf of Gascony (french: Golfe de Gascogne, oc, Golf de Gasconha, br, Pleg-mor Gwaskogn), ...

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 (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

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 (biology), class of generally marine invertebrate, marine annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that ...

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: * Spawn (biology), 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: Ar ...

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