Thaumatichthyidae, the wolftrap anglers or wolftrap seadevils, is a small

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 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 ...

, classified within the suborder Ceratioidei, the deep-sea anglerfishes. They have distinctive

upper jaw In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxillar ...

s with movable premaxillaries that can be lowered to form a cage-like trap around the much shorter

lower jaw In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

Taxonomy

''Thaumathichthyidae'' was first proposed as a

monotypic 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 "unisp ...

family in 1912 by the American ichthyologists

Hugh McCormick Smith Hugh McCormick Smith, also H. M. Smith (November 21, 1865 – September 28, 1941) was an American ichthyologist and administrator in the United States Bureau of Fisheries. Biography Smith was born in Washington, D.C. In 1888, he received a Doc ...

and

Lewis Radcliffe Lewis Radcliffe (1880–1950) was a naturalist, malacologist, and ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha ...

, with ''Thaumatichthys'' as its only genus. 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 in 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 ...

of the

anglerfish The anglerfish are ray-finned fish in the order Lophiiformes (). Both the order's common name, common and scientific name comes from the characteristic mode of predation, in which a modified dorsal Fish fin#Ray-fins, fin ray acts as a Aggressiv ...

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Lophiiformes The anglerfish are ray-finned fish in the order Lophiiformes (). Both the order's common and scientific name comes from the characteristic mode of predation, in which a modified dorsal fin ray acts as a lure for prey (akin to a human angler, ...

. Within the Ceratioidei this family is a

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

to the Oneirodidae.

Etymology

Thaumatichthyidae is derived from its

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 ...

, ''Thaumatochthys''. This name is a combination of "thauma", meaning "wonder" or "marvel", and ''ichthys'', the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

word for "fish". The name alludes to the strange shape of '' T. pagidostomus'' with its large head that is almost as long as the rest of the body, the esca and

illicium ''Illicium'' is a genus of flowering plants treated as part of the family Schisandraceae,

being inside the mouth to lure the prey into the huge trap-like mouth.

Genera

Thaumatichthydae has the following two genera classified within it:

Characteristics

Thaumatichthyidae anglerfishes resemble their close relatives the dreamers of the family Oneirodidae. The main differences are that the lower jaw projects well beyond the upper jaw and the upper part of the operculum is bifurcated. In comparison to other Ceratioid anglerfishes the wolftrap anglerfishes do not have the front end of the jawbones join at the midline of the mouth, where there is a wide elastic membrane. They have very long, inwardly hooked premaxillary teeth. They also have tooth-like denticles on the esca. The

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 ...

has between 14 and 20 soft rays while 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 ...

has 9 soft rays, the 3 middle rays being forked. The 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 ...

is for '' Thaumatichthys axeli'', while the smallest is in the case of '' Lasiognathus saccostoma''. Larvae have been recorded at while the largest free-living males are .

Distribution and habitat

Thaumatichthyidae anglerfishes are found at depths down to in the Atlantic and Pacific Oceans. Wolftrap anglers are thought to be unique among deep-sea anglerfish in adults remaining close to the

seabed The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as seabeds. The structure of the seabed of the global ocean is governed by plate tectonics. Most of ...

; specimens are consistently absent from pelagic nets and are typically caught using

bottom trawling Bottom trawling is trawling (towing a trawl, which is a fishing net) along the seafloor. It is also referred to as "dragging". The scientific community divides bottom trawling into benthic trawling and Demersal zone, demersal trawling. Benthic tra ...

. Additionally, benthic prey items were recovered from the stomach of a '' Th. binghami'', the only specimen of this family with stomach contents, being three well preserved '' Benthodytes typica'' measuring .

References

{{Taxonbar, from=Q134427 Ceratioidei Deep sea fish Marine fish families