The Myctophiformes are an

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

of ray-finned fishes consisting of two families of deep-sea

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

fish, most notably the highly abundant lanternfishes (Myctophidae). The

blackchin The Neoscopelidae (blackchins or neoscopelids) are a small family of deep-sea fish closely related to the lanternfish. They are found in tropical and subtropical marine waters worldwide. They can be distinguished from the lanternfish only by a f ...

s (Neoscopelidae) contain six species in three genera, while the bulk of the family belongs to the Myctophidae, with over 30 genera and some 252 species.Nelson (2006): p.223 The

scientific name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

ultimately derives from Ancient Greek ''myktér'' (μυκτήρ, "nose") + ''óphis'' (ὄφῖς, "serpent") + Latin ''forma'' ("external form"), the Greek part in reference to the long, slender, and heavy-headed shape of these fishes.

Description and ecology

These smallish fishes inhabit the pelagic and benthopelagic zones of the deep sea. They are laterally compressed and usually have photophores (light organs). The eyes are large, in some decidedly huge, and generally directed straight sideways. The mouth also quite large and located at the tip of the snout; its gape extends to below the eyes or even beyond. They have an adipose fin. The

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two en ...

has eight

ray Ray may refer to: Fish * Ray (fish), any cartilaginous fish of the superorder Batoidea * Ray (fish fin anatomy), a bony or horny spine on a fin Science and mathematics * Ray (geometry), half of a line proceeding from an initial point * Ray (g ...

s in most myctophiforms, and the number of

branchiostegal ray This glossary of ichthyology is a list of definitions of terms and concepts used in ichthyology, the study of fishes. A B C ...

s is usually higher than six and lower than 12.

Systematics

The two families of the Myctophiformes are: * Myctophidae – lanternfishes *

Neoscopelidae The Neoscopelidae (blackchins or neoscopelids) are a small family of deep-sea fish closely related to the lanternfish. They are found in tropical and subtropical marine waters worldwide. They can be distinguished from the lanternfish only by a f ...

– blackchins The

Myctophiformes is

anatomical Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having it ...

ly similar to the

grinner Aulopiformes is a diverse order of marine ray-finned fish consisting of some 15 extant and several prehistoric families with about 45 genera and over 230 species. The common names grinners, lizardfishes and allies, or aulopiforms are sometimes u ...

s (Aulopiformes), but their

pharyngobranchial Branchial arches, or gill arches, are a series of bony "loops" present in fish, which support the gills. As gills are the primitive condition of vertebrates, all vertebrate embryos develop pharyngeal arches, though the eventual fate of these arc ...

s and

retractor muscle Retractor may refer to: * Retractor (medical), a medical instrument * Retractor (memory), a person * Retractor (chess), type of a chess problem * Retractor muscle Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate ...

s are more plesiomorphic. It was also allied with the more advanced spiny- rayed

Teleostei Teleostei (; Ancient Greek, Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts ), is, by far, the largest class (biology), infraclass in the class Actinopterygii, the ray-finned fishes, containing 96% of a ...

(e.g.

Paracanthopterygii Paracanthopterygii is a superorder of fishes. Members of this group are called paracanthopterygians. It includes five orders: * † Sphenocephaliformes * Percopsiformes ( trout-perches & allies) * Zeiformes (dories) * Stylephoriformes ( Tube ...

) as " Ctenosquamata". These

apomorph In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...

ically have a fifth upper pharyngeal toothplate and a third internal levator muscle to move it, and

molecular A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioche ...

data also support the long-held view that these two lineages are at least closely related. Other sources ally them with the Lampriformes, which are often placed in a monotypic

superorder Order ( la, ordo) 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 ...

"Lampridiomorpha". In a similar fashion, separation of the Myctophiformes in superorder "Scopelomorpha" has been proposed. The Aulopiformes, though, are usually considered to be closer or even among the Protacanthopterygii, one of the core groups of moderately advanced teleosts. As modern taxonomy tries to avoid a profusion of small taxa, and the delimitation of the Euteleostei (Protacanthopterygii ''

sensu stricto ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular co ...

'' and their allies) versus "Ctenosquamata" such as the

remains uncertain, the

systematics Biological systematics is the study of the diversification of living forms, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees (synonyms: cladograms, phylogenetic tre ...

and taxonomy of the Myctophiformes among the teleosts are in need of further study.Nelson (2006): p.223, Diogo (2008)

Timeline of genera

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Early Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early ...

from: -99.6 till: -65.5 color:latecretaceous text:

Late Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, ...

from: -65.5 till: -55.8 color:paleocene text: Paleo. from: -55.8 till: -33.9 color:eocene text: Eo. from: -33.9 till: -23.03 color:oligocene text: Oligo. from: -23.03 till: -5.332 color:miocene text: Mio. from: -5.332 till: -2.588 color:pliocene text:

Pl. PL, P.L., Pl, or .pl may refer to: Businesses and organizations Government and political * Partit Laburista, a Maltese political party * Liberal Party (Brazil, 2006), a Brazilian political party * Liberal Party (Moldova), a Moldovan political p ...

from: -2.588 till: -0.0117 color:pleistocene text:

from: -0.0117 till: 0 color:holocene text: H. bar:eratop from: -145.5 till: -65.5 color:cretaceous text: Cretaceous from: -65.5 till: -23.03 color:paleogene text:

Paleogene The Paleogene ( ; British English, also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period, geologic period and system that spans 43 million years from the end of the Cretaceous Period million yea ...

from: -23.03 till: -2.588 color:neogene text:

Neogene The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...

from: -2.588 till: 0 color:quaternary text: Q. PlotData= align:left fontsize:M mark:(line,white) width:5 anchor:till align:left color:latecretaceous bar:NAM1 from: -99.6 till: -70.6 text:

Sardinoides ''Sardinioides'' is an extinct genus of prehistoric ray-finned fish from the Campanian. It is a member of the Myctophiformes order, and considered a sister group to Paleogene and modern neoscopelids and myctophids Lanternfishes (or myctophid ...

color:latecretaceous bar:NAM2 from: -85.8 till: -83.5 text:

Chirothrix ''Cheirothrix'' (meaning "hand hair") is an extinct genus of ray-finned fish. One of the species in this genus is '' Cheirothrix lewisii'', known from the Late Cretaceous of Lebanon Lebanon ( , ar, لُبْنَان, translit=lubnān, ), o ...

color:latecretaceous bar:NAM3 from: -83.5 till: -70.6 text:

Sardinius ''Sardinius'' is an extinct genus of prehistoric 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 ...

color:paleocene bar:NAM4 from: -65.5 till: -55.8 text: Neocassandra color:paleocene bar:NAM5 from: -65.5 till: -55.8 text: Eokrefftia color:eocene bar:NAM6 from: -55.8 till: 0 text:

Diaphus ''Diaphus'' is a genus of lanternfish Lanternfishes (or myctophids, from the Greek μυκτήρ ''myktḗr'', "nose" and ''ophis'', "serpent") are small mesopelagic fish of the large family Myctophidae. One of two families in the order Myct ...

color:eocene bar:NAM7 from: -48.6 till: -23.03 text:

Eomyctophum ''Eomyctophum'' is an extinct genus of prehistoric 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 ...

color:oligocene bar:NAM8 from: -28.4 till: 0 text:

Lobianchia ''Lobianchia'' is a genus of lanternfishes found in the Atlantic Ocean. The generic name was derived from Latin ''lobus'' ("lobe") and Greek αγχόνη (''anchonē'', "noose"). Species There are currently two recognized species in this genus: ...

color:oligocene bar:NAM9 from: -28.4 till: 0 text: Hygophum color:miocene bar:NAM10 from: -23.03 till: 0 text:

Symbolophorus ''Symbolophorus'' is a genus of lanternfishes. It feeds on various small forms of sea life, in particular fish. Some species in this genus are known to exhibit the Stylophthalmine trait in their larval form Species There are currently eight re ...

color:miocene bar:NAM11 from: -23.03 till: 0 text:

Lampanyctus ''Lampanyctus'' is a genus of lanternfishes. Species There are currently 39 recognized species in this genus: * '' Lampanyctus acanthurus'' Wisner, 1974 (Spinytail lampfish) * '' Lampanyctus achirus'' Andriashev, 1962 (Cripplefin Lanternfish ...

color:miocene bar:NAM12 from: -23.03 till: 0 text: Bolinichthyes color:miocene bar:NAM13 from: -15.97 till: 0 text:

Notoscopelus ''Notoscopelus'' is a genus of lanternfishes. Species There are currently six recognized species in this genus: * ''Notoscopelus bolini'' Basil George Nafpaktitis, B. G. Nafpaktitis, 1975 * ''Notoscopelus caudispinosus'' (James Yate Johnson, J. ...

color:miocene bar:NAM14 from: -15.97 till: 0 text: Benthosema color:miocene bar:NAM15 from: -11.608 till: 0 text:

Myctophum ''Myctophum'' is a genus of lanternfishes, some species of which, such as ''M. punctatum'' are noted for having the Stylophthalmine trait in their larval form. Species There are currently 16 recognized species in this genus: * '' Myctophum af ...

color:miocene bar:NAM16 from: -11.608 till: 0 text: Lampichthyes color:miocene bar:NAM17 from: -11.608 till: 0 text: Lampanyctodes color:miocene bar:NAM18 from: -11.608 till: 0 text:

Electrona Electrona may refer to: * ''Electrona'' (fish), a genus of lanternfishes in the family Myctophidae * Electrona, Tasmania, a town in Tasmania, Australia {{disambig ...

color:pliocene bar:NAM19 from: -5.332 till: 0 text:

Triphoturus ''Triphoturus'' is a genus of lanternfishes. Species There are currently three recognized species in this genus: * ''Triphoturus mexicanus'' (Charles Henry Gilbert, C. H. Gilbert, 1890) (Mexican lampfish) * ''Triphoturus nigrescens'' (August Ber ...

color:pliocene bar:NAM20 from: -5.332 till: 0 text:

Tarletonbeania ''Tarletonbeania'' is a genus of lanternfishes found in the Pacific Ocean. Etymology The genus is named after ichthyologist Tarleton H. Bean (1846-1916), of the U.S. National Museum. Species There are currently two recognized species in this ge ...

color:pliocene bar:NAM21 from: -5.332 till: 0 text:

Stenobrachius ''Stenobrachius'' is a genus of lanternfish Lanternfishes (or myctophids, from the Greek μυκτήρ ''myktḗr'', "nose" and ''ophis'', "serpent") are small mesopelagic fish of the large family Myctophidae. One of two families in the order ...

color:pliocene bar:NAM22 from: -5.332 till: 0 text: Scopelopsis color:pliocene bar:NAM23 from: -5.332 till: 0 text: Protomyctophum color:pliocene bar:NAM24 from: -5.332 till: 0 text:

Parvilux ''Parvilux'' is a genus of lanternfish Lanternfishes (or myctophids, from the Greek μυκτήρ ''myktḗr'', "nose" and ''ophis'', "serpent") are small mesopelagic fish of the large family Myctophidae. One of two families in the order Myct ...

color:pliocene bar:NAM25 from: -5.332 till: 0 text:

Lampadena ''Lampadena'' is a genus of lanternfishes. Species There are currently nine recognized species in this genus: * '' Lampadena anomala'' A. E. Parr, 1928 * '' Lampadena chavesi'' Collett, 1905 (Chaves' lanternfish) * '' Lampadena dea'' Fraser-B ...

color:pliocene bar:NAM26 from: -5.332 till: 0 text:

Gymnoscopelus ''Gymnoscopelus'' is a genus of lanternfishes. The name is from the Greek ''gymnos'', "naked" and ''skopelos'', "lanternfish." They can live in extremely cold water; two species, '' Gymnoscopelus nicholsi'' and '' Gymnoscopelus braueri'', have b ...

color:pliocene bar:NAM27 from: -5.332 till: 0 text:

Ceratoscopelus ''Ceratoscopelus'' is a genus of lanternfish Lanternfishes (or myctophids, from the Greek μυκτήρ ''myktḗr'', "nose" and ''ophis'', "serpent") are small mesopelagic fish of the large family Myctophidae. One of two families in the orde ...

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from: -99.6 till: -65.5 color:latecretaceous text:

from: -2.588 till: -0.0117 color:pleistocene text:

from: -0.0117 till: 0 color:holocene text: H. bar:era from: -145.5 till: -65.5 color:cretaceous text: Cretaceous from: -65.5 till: -23.03 color:paleogene text:

from: -23.03 till: -2.588 color:neogene text:

from: -2.588 till: 0 color:quaternary text: Q.

Footnotes

References

* (2008): On the cephalic and pectoral girdle muscles of the deep sea fish ''Alepocephalus rostratus'', with comments on the functional morphology and phylogenetic relationships of the Alepocephaloidei (Teleostei). '' Anim. Biol.'' 58(1): 23-29. * (2006)
Order Myctophiformes
Version of 2006-OCT-09. Retrieved 2009-SEP-28. * (1968–1982): ''

Oxford Latin Dictionary The ''Oxford Latin Dictionary'' (or ''OLD'') is the standard English lexicon of Classical Latin, compiled from sources written before AD 200. Begun in 1933, it was published in fascicles between 1968 and 1982; a lightly revised second edition ...

'' (1st ed.). Oxford University Press, Oxford. * (2006): ''

Fishes of the World ''Fishes of the World'' by the American ichthyologist Joseph S. Nelson (1937–2011) is a standard reference for fish systematics. Now in its fifth edition (2016), the work is a comprehensive overview of the diversity and classification of the ...

'' (4th ed.). John Wiley & Sons, Inc. * (1910): ''English-Greek Dictionary - A Vocabulary of the Attic Language''. George Routledge & Sons Ltd., Broadway House, Ludgate Hill, E.C
Searchable JPEG fulltext
* {{Authority control Deep sea fish Ray-finned fish orders