Trachichthyiformes

The Trachichthyiformes /træˈkɪkθi.ɪfɔːrmiːz/ are an order of ray-finned fishes in the superorder Acanthopterygii.

Trachichthyiformes Temporal range: Cenomanian–present PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Superorder:	Acanthopterygii
Order:	Trachichthyiformes Moore, 1993[1]
Families
Anoplogastridae Diretmidae Anomalopidae Monocentridae Trachichthyidae

Fossils of this group date back to the Cenomanian.^[2][3]

Member genera include the flashlight fishes, fangtooth fishes, spinyfins, pineconefishes, redfishes, roughies, and slimeheads. A number of member species are caught commercially, most notably the orange roughy.^[4] Some species have bioluminescent bacteria contained in pockets of skin or in light organs near the eyes, including the anomalopids and monocentrids.^[5]

Etymology

The name comes from Ancient Greek τραχύς (trakhús), meaning "rough", ἰχθύς (ikhthús), meaning "fish", and Latin formes, meaning "form".

Phylogeny

A recent phylogeny based on the work of Betancur-Rodriguez et al. 2017 shows Trachichthyiformes as a sister group of Beryciformes in the clade Berycimorpha.^[6]

Acanthopterygii	Berycimorpha Beryciformes Berycoidei Melamphaidae Berycidae Stephanoberycoidei Cetomimidae Rondeletiidae Barbourisiidae Stephanoberycidae Trachichthyiformes Diretmidae Trachichthyoidea Monocentridae Anomalopidae Trachichthyidae Holocentrimorpha Holocentriformes Holocentridae Percomorpha (many orders and families)