''Linophryne'', the bearded seadevils, is a

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 ...

of marine

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

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 ...

Linophrynidae, the leftvents. These deep sea anglerfishes are found in the Atlantic, Indian and Pacific Oceans.

Taxonomy

''Linophryne'' was first proposed as a

monospecific genus In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

in 1886 by the Norwegian

zoologist Zoology ( , ) is the scientific study of animals. Its studies include the structure, embryology, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. Zoology is one ...

Robert Collett Robert Collett (2 December 1842 – 27 January 1913) was a Norway, Norwegian zoologist. Collett was director and curator of the Natural History Museum at the University of Oslo, Zoological Museum at University of Oslo. Robert Collett was born at ...

when he described ''L. lucifer'' as a new species. Collett gave the type locality of ''L. lucifer'' as off

Madeira Madeira ( ; ), officially the Autonomous Region of Madeira (), is an autonomous Regions of Portugal, autonomous region of Portugal. It is an archipelago situated in the North Atlantic Ocean, in the region of Macaronesia, just under north of ...

at around 36°N, 20°W. 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 genus within the family Linophrynidae, which it places 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 ...

Ceratioidei Ceratioidei, the deep-sea anglerfishes or pelagic anglerfishes, is a suborder of marine ray-finned fishes, one of five suborders in the order Lophiiformes, the anglerfishes. These fishes are found in tropical and temperate seas throughout the wor ...

, the deep sea anglerfishes, within the order Lophiiformes, the anglerfishes.

Etymology

''Linophryne'' prefixes ''linos'', which means "net", an allusion Collett did not explain when he proposed the genus, with ''phryne'', meaning "toad". The prefix may be a reference to the sac like mouth hanging off the trunk, which in the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

contained a

lanternfish Lanternfish (or myctophids, from the Greek language, Greek μυκτήρ ''myktḗr'', "nose" and ''ophis'', "serpent") are small mesopelagic fish of the large family (biology), family Myctophidae. One of two families in the order Myctophiformes, ...

, like a fisherman's keep net. The second part ''phryne'' is commonly used in the names of anglerfish genera. Its use may date as far back 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 ...

and

Cicero Marcus Tullius Cicero ( ; ; 3 January 106 BC – 7 December 43 BC) was a Roman statesman, lawyer, scholar, philosopher, orator, writer and Academic skeptic, who tried to uphold optimate principles during the political crises tha ...

, who referred to anglerfishes as "fishing-frogs" and "sea-frogs," respectively, possibly because of their resemblance to frogs and toads.

Characteristics

''Linophryne'' leftvents are

sexually dimorphic Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

and the

metamorphosed Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causi ...

females can be distinguished from the other leftvent genera by a number of characters. These include the possession of a hyoid

barbel Barbel may refer to: *Barbel (anatomy), a whisker-like organ near the mouth found in some fish (notably catfish, loaches and cyprinids) and turtles *Barbel (fish), a common name for certain species of fish **''Barbus barbus'', a species of cyprini ...

, well-developed spines on the sphenotic bone and the

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

and a single nearly oval bulb on the

esca Esca can refer to: * The esca or illicium, a modified luminescent fin ray found in anglerfish * Esca (grape disease) * the Ezka, a river in the Basque country known as "Esca" in Spanish * ESCA or Electron Spectroscopy for Chemical Analysis, now ...

with a short projection in its middle and has no appendages as well as a low number of fin rays in the

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

and

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 ...

s. The barbel filaments contain globular,

bioluminescent Bioluminescence is the emission of light during a chemiluminescence reaction by living organisms. Bioluminescence occurs in multifarious organisms ranging from marine vertebrates and invertebrates, as well as in some fungi, microorganisms inc ...

organs. The barbels do not contain bacteria like the esca but complex paracrystalline photogenic granules. The esca is

ectoderm The ectoderm is one of the three primary germ layers formed in early embryonic development. It is the outermost layer, and is superficial to the mesoderm (the middle layer) and endoderm (the innermost layer). It emerges and originates from the o ...

al in origin whereas the barbel organs may be derived from the

mesoderm The mesoderm is the middle layer of the three germ layers that develops during gastrulation in the very early development of the embryo of most animals. The outer layer is the ectoderm, and the inner layer is the endoderm.Langman's Medical ...

. The different species are distinguished by

character Character or Characters may refer to: Arts, entertainment, and media Literature * ''Character'' (novel), a 1936 Dutch novel by Ferdinand Bordewijk * ''Characters'' (Theophrastus), a classical Greek set of character sketches attributed to Theoph ...

s of the esca and barbel; males of the genus cannot be differentiated in morphology. Both sexes are pigmented after metamorphosis, being black in color. They have no scales and

gelatinous Gelatin or gelatine () is a translucent, colorless, flavorless food ingredient, commonly derived from collagen taken from animal body parts. It is brittle when dry and rubbery when moist. It may also be referred to as hydrolysis, hydrolyzed col ...

skin. The largest species in the genus is ''L. lucifer'' which 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 .

Species

''Linophryne'' contains 22 recognised species, these are divided into 3 subgenera: * Subgenus ''Linophryne'' Collett, 1886 ** '' Linophryne algibarbata'' Waterman, 1939 ** '' Linophryne arcturi'' Beebe, 1926 ** '' Linophryne argyresca'' Regan & Trewavas, 1932 ** '' Linophryne bicornis'' Parr, 1927 ** '' Linophryne bipennata'' Bertelsen, 1982 ** '' Linophryne coronata'' Parr, 1927 ** '' Linophryne escaramosa'' Bertelsen, 1982 ** '' Linophryne lucifer'' Collett, 1886 ** '' Linophryne macrodon'' Regan, 1925 ** '' Linophryne maderensis''

Maul A maul may refer to any number of large hammers, including: * War hammer, a medieval weapon * Post maul, a type of sledgehammer * Spike maul, railroad hand tool * Splitting maul, heavy wood-splitting tool resembling both axe and hammer People * A ...

, 1961 ** '' Linophryne polypogon'' Regan, 1925 ** '' Linophryne racemifera'' Regan & Trewavas, 1932 ** '' Linophryne sexfilis'' Bertelsen, 1973 ** ''

Linophryne trewavasae ''Linophryne'', the bearded seadevils, is a genus of Marine life, marine Actinopterygii, ray-finned fishes belonging to the Family (biology), family leftvent, Linophrynidae, the leftvents. These Ceratioidei, deep sea anglerfishes are found in the ...

'' Bertelsen, 1978 *Subgenus ''Rhizophryne'' Bertelsen, 1982 ** '' Linophryne andersoni'' Gon, 1992 ** '' Linophryne arborifera'' Regan, 1925 ** '' Linophryne brevibarbata'' Beebe, 1932 ** '' Linophryne densiramus'' S. Imai, 1941 (Thickbranch angler) ** '' Linophryne parini'' Bertelsen, 1980 ** ''

Linophryne pennibarbata ''Linophryne'', the bearded seadevils, is a genus of marine ray-finned fishes belonging to the family Linophrynidae, the leftvents. These deep sea anglerfishes are found in the Atlantic, Indian and Pacific Oceans. Taxonomy ''Linophryne'' was ...

'' Bertelsen, 1980 *Subgenus ''Stephanophryne'' Bertelsen, 1982 ** '' Linophryne indica''

Brauer Brauer or Bräuer is a surname of German origin, meaning "brewer". Notable people with the name include:- * Alfred Brauer (1894–1985), German-American mathematician, brother of Richard * Andreas Brauer (born 1973), German film producer * Arik Bra ...

, 1902 (Headlight angler) ** '' Linophryne quinqueramosus'' Beebe & Crane, 1947

Fossil record

''Linophryne'' is represented in the fossil record by what may be ''L. indica'' was found in Late

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

-aged

Puente Formation The Puente Formation is a Formation (geology), geologic formation in California. It preserves fossils dating back to the middle to upper Miocene epoch of the Neogene Period (geology), period, most of which were deposited in a deepwater environment ...

Los Angeles Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, along with a fossil of the related '' Borophryne apogon'', during the construction of a

metrorail METRORail is the light rail system in Houston, Texas (United States). In , the system had a ridership of , or about per weekday as of . METRORail ranks as the second most-traveled light rail system in the Southern United States and the List ...

Distribution and habitat

''Linophryne'' is found circumglobally in all three equatorial Oceans, up to as far north as Iceland and Greenland in the Atlantic Ocean. They are found at depths between .

Gallery

References

{{Taxonbar, from=Q1957487 Linophrynidae Marine fish genera Taxa named by Robert Collett