Notacanthiformes
Encyclopedia
Notacanthiformes is an order
of deep-sea ray-finned fishes, consisting of the families Halosauridae and Notacanthidae
(spiny eel
s)
The order is of relatively recent vintage; Fishes of the World
lists it as a suborder Notacanthoidei of Albuliformes. The notacanthiforms are much more eel
-like than the albuliforms; for instance, the caudal fin has disappeared.
Fish of the order are found in oceans worldwide, at depths from 120 metres (393.7 ft) to 4900 metres (16,076.1 ft). They are elongated fish, although not as much so as the true eels. They typically feed on slow-moving or sessile animals, such as molluscs, echinoderm
s, and sea anemone
s. Like the true eels, they have a leptocephalus
larva that floats in the surface waters before transforming into an adult. Unusually, the larva can often be larger than the adult.
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
of deep-sea ray-finned fishes, consisting of the families Halosauridae and Notacanthidae
Notacanthidae
The deep-sea spiny eels are a family, Notacanthidae, of fishes found worldwide below , and going as deep as .Their bodies of deep sea spiny eels are greatly elongated, though more tapered than in true eels. The caudal fin is small or nonexistent, while the anal fin is lengthy, as long as half of...
(spiny eel
Spiny eel
The name spiny eel is used to describe members of two different families of fish: the freshwater Mastacembelidae of Asia and Africa, and the marine Notacanthidae. Both are so-named because of their eel-like shape and sturdy fin spines....
s)
The order is of relatively recent vintage; Fishes of the World
Fishes of the World
Fishes of the World by Joseph S. Nelson is a standard reference for fish systematics. Now in its fourth edition, the work is a comprehensive overview of the 25,000-plus species known to science....
lists it as a suborder Notacanthoidei of Albuliformes. The notacanthiforms are much more eel
Eel
Eels are an order of fish, which consists of four suborders, 20 families, 111 genera and approximately 800 species. Most eels are predators...
-like than the albuliforms; for instance, the caudal fin has disappeared.
Fish of the order are found in oceans worldwide, at depths from 120 metres (393.7 ft) to 4900 metres (16,076.1 ft). They are elongated fish, although not as much so as the true eels. They typically feed on slow-moving or sessile animals, such as molluscs, echinoderm
Echinoderm
Echinoderms are a phylum of marine animals. Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone....
s, and sea anemone
Sea anemone
Sea anemones are a group of water-dwelling, predatory animals of the order Actiniaria; they are named after the anemone, a terrestrial flower. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Zoantharia. Anthozoa often have large polyps that allow for digestion of larger...
s. Like the true eels, they have a leptocephalus
Leptocephalus
A leptocephalus is the flat and transparent larva of the eel, marine eels, and other members of the Superorder Elopomorpha. Fishes with a leptocephalus larva stage include the most familiar eels such as the conger, moray eel, and garden eel, and the freshwater eels of the family Anguillidae, plus...
larva that floats in the surface waters before transforming into an adult. Unusually, the larva can often be larger than the adult.