The Stephanoberyciformes 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 ...

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 h ...

es, consisting of about 68 species, the majority (61) of which belong to the

ridgehead Ridgeheads, also known as bigscales, are a family (Melamphaidae, from the Greek ''melanos'' lackand ''amphi'' y both sides of small, deep-sea stephanoberyciform fish. The family contains approximately 37 species in five genera; their distributio ...

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

(Melamphaidae). The Stephanoberyciformes are mostly uncommon

deep-sea The deep sea is broadly defined as the ocean depth where light begins to fade, at an approximate depth of 200 metres (656 feet) or the point of transition from continental shelves to continental slopes. Conditions within the deep sea are a combin ...

species with little, if any, importance to commercial

fishery Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place (a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, ...

. They share many morphological similarities with the

Beryciformes The Beryciformes are a poorly-understood order of carnivorous ray-finned fishes consisting of 7 families, 30 genera, and 161 species. They feed on small fish and invertebrates. Beyond this, little is known about the biology of most member specie ...

, their sister order. Some sources classify their other close relatives, the whalefishes, as a

superfamily SUPERFAMILY is a database and search platform of structural and functional annotation for all proteins and genomes. It classifies amino acid sequences into known structural domains, especially into SCOP superfamilies. Domains are functional, str ...

herein, named Cetomimoidea. Most taxa traditionally placed here would then be the Stephanoberyciodea. The

families Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

are: * Melamphaidae – ridgeheads (about 61 species) *

Gibberichthyidae The Gibberichthyidae, also known as gibberfishes, are a small family of deep sea stephanoberyciform fish, containing a single genus, ''Gibberichthys'' (from the Latin ''gibba'', "humpbacked" and the Greek ''ichthys'', "fish"), and two species. ...

– gibberfishes (2 species) * Stephanoberycidae – pricklefishes (4 species) * Hispidoberycidae - Bristlyskin (1 species) Common characteristics include a generally rounded body, a toothless

palate The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly s ...

, rather thin

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, t ...

bones, and a missing orbitosphenoid bone (except for '' Hispidoberyx''). The gibberfishes on the other hand appear to be closer to whalefishes such as '' Rondeletia'', as has been proposed time and again. These two groups have - apparently as only living fishes - the mysterious Tominaga's organ (A large mass of globular white tissue, that present anterior to the orbit and posterior and medial to the nostrils and nasal rosette). ''Rondeletia'', meanwhile, is suspected to be very close to the

velvet whalefish file:Bitcoin cufflinks (cropped).JPG, Weave details visible on a purple-colored velvet fabric Velvet is a type of woven tufted textile, fabric in which the cut yarn, threads are evenly distributed, with a short pile (textile), pile, giving it ...

, ''Barbourisia rufa''.Paxton ''et al.'' (2001)

Footnotes

References

* (2006): ''

Fishes of the World ''Fishes of the World'' by the American Ichthyology, 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 classificat ...

'' (4th ed.). * (2001): Larvae and juveniles of the deepsea "whalefishes" ''Barbourisia'' and ''Rondeletia'' (Stephanoberyciformes: Barbourisiidae, Rondeletiidae), with comments on family relationships. ''Records of the Australian Museum'' 53(3): 407-425
PDF fulltext

External links

* {{Taxonbar, from=Q621519 Ray-finned fish orders