Osteoglossiformes
Encyclopedia
Osteoglossiformes is a relatively primitive order
of ray-finned fish that contains two sub-orders, the Osteoglossoidei
and the Notopteroidei
. All of the living species inhabit freshwater. They are found in South America, Africa, Australia and southern Asia, having first evolved in Gondwana
before that continent broke up.
The mooneyes (Hiodontidae) are often classified here, but may also be placed in a separate order Hiodontiformes
.
Members of the order are notable for having toothed or bony tongues, and for having the forward part of the gastrointestinal tract
pass to the left of the oesophagus and stomach
(for all other fish it passes to the right). In other respects, osteoglossiform fishes vary considerably in size and form; the smallest is Pollimyrus castelnaui, at just 2 centimetre (0.78740157480315 in) long, while the largest, the arapaima
(Arapaima gigas), reaches as much as 2.5 metres (8.2 ft).
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 ray-finned fish that contains two sub-orders, the Osteoglossoidei
Osteoglossoidei
Osteoglossoidei are a sub-order of the group Osteoglossiformes that contains the butteryflyfishes and the arowanas. as well as extinct families....
and the Notopteroidei
Notopteroidei
Notopteroidei is a sub-order of the group Osteoglossiformes that contains the Notopteridae and mormyrids as well as extinct families....
. All of the living species inhabit freshwater. They are found in South America, Africa, Australia and southern Asia, having first evolved in Gondwana
Gondwana
In paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...
before that continent broke up.
The mooneyes (Hiodontidae) are often classified here, but may also be placed in a separate order Hiodontiformes
Hiodontiformes
Hiodontiformes is a relatively new order of fish, consisting of the two living species of the mooneye family Hiodontidae and three genera of extinct types....
.
Members of the order are notable for having toothed or bony tongues, and for having the forward part of the gastrointestinal tract
Gastrointestinal tract
The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....
pass to the left of the oesophagus and stomach
Stomach
The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
(for all other fish it passes to the right). In other respects, osteoglossiform fishes vary considerably in size and form; the smallest is Pollimyrus castelnaui, at just 2 centimetre (0.78740157480315 in) long, while the largest, the arapaima
Arapaima
The arapaima, pirarucu, or paiche is a South American tropical freshwater fish. It is a living fossil and one of the largest freshwater fishes in the world.-Anatomy and morphology:...
(Arapaima gigas), reaches as much as 2.5 metres (8.2 ft).
External links
- Mikko's Phylogeny for Osteoglossiformes
- Osteoglossiforms for aquaria
- Li, Guo-Qing and Wilson, Mark V. H. 1998. Osteoglossomorpha. Bonytongues. Version 6 October 1998. http://tolweb.org/Osteoglossomorpha/15071/1998.10.06 in The Tree of Life Web ProjectTree of Life Web ProjectThe Tree of Life Web Project is an ongoing Internet project providing information about the diversity and phylogeny of life on Earth. This collaborative peer reviewed project began in 1995, and is written by biologists from around the world....