''Pholidae'' is a

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 ...

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 ...

es, known as gunnels, in the scorpaeniform suborder Zoarcoidei. These are fishes of the

littoral zone The littoral zone, also called litoral or nearshore, is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely flood ...

and are mainly found in North Pacific Ocean, with two species found in the North Atlantic Ocean and Arctic Ocean.

Taxonomy

Pholidae was first put forward as a family in 1893 by the American zoologist Theodore Gill. The 5th edition of ''

Fishes of the World ''Fishes of the World'' is a standard reference for the systematics of fishes. It was first written in 1976 by the American ichthyologist Joseph S. Nelson (1937–2011). Now in its fifth edition (2016), the work is a comprehensive overview of t ...

'' classifies this family within the

suborder Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized ...

Zoarcoidei Zoarcoidei is a suborder of marine ray-finned fishes belonging to the Order (biology), order Perciformes. The suborder includes the wolffishes, Pholidae, gunnels and eelpouts. The suborder includes about 400 species. These fishes are predominantl ...

, within the order Scorpaeniformes. Other authorities classify this family in the

infraorder Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between Family_(biology), family and Class_(biology), class. In biological classification, the order is a taxonomic rank used in the classific ...

Zoarcales within the suborder Cottoidei of the

Perciformes Perciformes (), also called the Acanthopteri, is an order or superorder of ray-finned fish in the clade Percomorpha. ''Perciformes'' means " perch-like". Among the well-known members of this group are perches and darters ( Percidae), and als ...

because removing the Scorpaeniformes from the Perciformes renders that taxon non

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

Etymology and spelling

Pholidae is derived from the name of the

type genus In biological taxonomy, the type genus (''genus typica'') is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearin ...

''Pholis'' which is an

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

name for a fish that hides in a hole, the name dating at least as far in history as

Aristotle Aristotle (; 384–322 BC) was an Ancient Greek philosophy, Ancient Greek philosopher and polymath. His writings cover a broad range of subjects spanning the natural sciences, philosophy, linguistics, economics, politics, psychology, a ...

. The family has been spelled as Pholididae, and this is grammatically correct, but Article 29 of the

International Code of Zoological Nomenclature The International Code of Zoological Nomenclature (ICZN) is a widely accepted Convention (norm), convention in zoology that rules the formal scientific name, scientific naming of organisms treated as animals. It is also informally known as the I ...

permits the use of Pholidae.

Characteristics

Pholidae, the gunnels, have elongate, compressed bodies which resemble that of

blennies Blennies (from the Greek and , mucus, slime) are a diverse clade of ray-finned fish in the suborder Blennioidei of the percomorph order Blenniiformes. They inhabit marine, brackish, and occasionally freshwater habitats, and generally share simi ...

. There is a single continuous

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 ...

, which has a base that is roughly double the length to that of 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 ...

, the dorsal fin extends from the head to the

caudal 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 only ...

. The dorsal fin contains between 73 and 100 stiff spines while the anal fin has between 1 and 3 spines and 32 to 53 soft rays. The anal fin and the dorsal fin are joined to the rounded caudal fin. Some species have no

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 ...

s but where they are present they are very small. The

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins (the other being the laterally positioned pectoral fins). The pelvic fins are homologous to the hi ...

s are also small, if present, and very simple with a single spine and a single soft ray. There is a single pair of nostrils. The body is covered with very small, difficult to see, cycloid scales which are covered in mucus. the sensory canals on the head have pores which are open to the outside. 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 ...

runs along the middle of the flanks and is made up of a row of superficial neuromasts. The teeth are small and conical. The gill membranes have a wide joining and they are separate from the isthmus. There are no ribs. They are camouflaged fishes with coloration which can be yellow and brown to red or green, frequently they are marked with spots, blotches, and bands. The largest species is the penpoint gunnel (''Apodichthys flavidus''} which attains a maximum published total length of while the smallest is ''

Pholis nea ''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 ...

'' which has a maximum published total length of .

Distribution, habitat and biology

Pholidae gunnels are predominantly found in the North Pacific Ocean off the western coasts of North America and the eastern coasts of Asia, except for two species in the genus ''Pholis'' which are found in the Arctic and North Atlantic Oceans. They are mostly found in rocky intertidal and nearby shallow waters below the tide line, particularly in areas of

kelp Kelps are large brown algae or seaweeds that make up the order (biology), order Laminariales. There are about 30 different genus, genera. Despite its appearance and use of photosynthesis in chloroplasts, kelp is technically not a plant but a str ...

and other seaweeds. They frequently hide under rocks and in rock pools in the intertidal zone. Their diet is made up of small crustaceans and molluscs.

References

* {{Taxonbar, from=Q1018093 Zoarcoidei Taxa named by Theodore Gill