Myctophiformes

Myctophiformes
Spotted Lanternfish (Myctophum punctatum)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Subkingdom:	Eumetazoa
Superphylum:	Deuterostomia
Phylum:	Chordata
Subphylum:	Vertebrata
Infraphylum:	Gnathostomata
Superclass:	Osteichthyes
Class:	Actinopterygii
Subclass:	Neopterygii
Infraclass:	Teleostei
Superorder:	Scopelomorpha (disputed)
Order:	Myctophiformes
Families
Myctophidae Neoscopelidae

Myctophiformes is an order of ray-finned fish consisting of two families of deep-sea marine fish, most notably the highly abundant lanternfishes (Myctophidae). The blackchins (Neoscopelidae) contain a handful of species in three genera, while the bulk of the family belongs to the Myctophidae, with over 30 genera and almost 250 species.^[1]

The scientific name means "Ateleopus-shaped", from Ateleopus (the type genus) + the standard fish order suffix "-formes". It 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.^[2]

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 has 8 rays in most myctophiforms, and the number of branchiostegal rays is usually higher than 6 and lower than a dozen.^[1]

Systematics

The two families of the Myctophiformes are:^[3]

• Myctophidae – lanternfishes
• Neoscopelidae – blackchins

The order Myctophiformes is anatomically similar to the grinners (Aulopiformes), but their pharyngobranchials and retractor muscles are more plesiomorphic. It was also allied with the more advanced spiny-rayed Teleostei (e.g. Paracanthopterygii) as "Ctenosquamata". These apomorphically have a fifth upper pharyngeal toothplate and a third internal levator muscle to move it, and molecular data also supports 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 "Lampridiomorpha". In a similar fashion, separation of the Myctophiformes in superorder "Scopelomorpha" has been proposed. The Aulopiformes, meanwhile, 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 and their allies) versus "Ctenosquamata" such as the Paracanthopterygii remains uncertain, the systematics and taxonomy of the Myctophiformes among the teleosts are in need of further study.^[4]

Timeline of genera

Footnotes

1. ^ ^{a b} Nelson (2006): p.223
2. ^ Woodhouse (1910), Glare (1968-1982), FishBase (2006)
3. ^ FishBase (2006)
4. ^ Nelson (2006): p.223, Diogo (2008)

References

• Diogo, Rui (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. doi:10.1163/157075608X303636
• FishBase (2006): Order Myctophiformes. Version of 2006-OCT-09. Retrieved 2009-SEP-28.
• Glare, P.G.W. (ed.) (1968-1982): Oxford Latin Dictionary (1st ed.). Oxford University Press, Oxford. ISBN 0-19-864224-5
• Nelson, Joseph S. (2006): Fishes of the World (4th ed.). John Wiley & Sons, Inc. ISBN 0471250317
• Woodhouse, S.C. (1910): English-Greek Dictionary - A Vocabulary of the Attic Language. George Routledge & Sons Ltd., Broadway House, Ludgate Hill, E.C. Searchable JPEG fulltext
• Sepkoski, Jack (2002). "A compendium of fossil marine animal genera". Bulletins of American Paleontology 364: p.560. http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=611&rank=class. Retrieved 2011-05-17.