Arowana
Encyclopedia
Arowanas are freshwater
bony fish of the family Osteoglossidae, also known as bonytongues. In this family of fishes, the head is bony and the elongate body is covered by large, heavy scales, with a mosaic pattern of canals. The dorsal and the anal fins have soft rays and are long based, while the pectoral and ventral fins are small. The name "bonytongues" is derived from a toothed bone on the floor of the mouth, the "tongue", equipped with teeth that bite against teeth on the roof of the mouth. The fish can obtain oxygen from air by sucking it into the swim bladder
, which is lined with capillaries like lung tissue
. The arowana is an "obligatory air breather".
(primitive) fish from the lower Tertiary
and are placed in the actinopterygii
d order Osteoglossiformes
. There are ten described living species
: three from South America
, one from Africa
, four from Asia
, and the remaining two from Australia
.
Osteoglossidae is the only exclusively freshwater fish family found on both sides of the Wallace Line
. This may be explained by the theroy that Asian arowana
s (S. formosus) diverged from the Australian Scleropages, S. jardinii and S. leichardti, about 140 million years ago, making it likely that Asian arowanas were carried to Asia
on the Indian subcontinent
.
, often being specialized surface feeders. They are excellent jumpers; it has been reported that Osteoglossum species have been seen leaping more than 6 feet (almost 2 metres) from the water surface to pick off insects and birds from overhanging branches in South America, hence the nickname "water monkeys". Arowana species typically grow to around 2 to 3 feet in captivity.
Several species of osteoglossid exhibit extensive parental care. They build nests and protect the young after they hatch. All species are mouthbrooder
s, the parents holding sometimes hundreds of eggs in their mouths. The young may make several tentative trips outside the parent's mouth to investigate the surroundings before leaving permanently.These fishes are best kept with live or frozen feed and they easily outgrow the tank within a span of 8-10 months. Always preferred in a large type aquarium of at least 150 gallons.
, oscars, plecostomus
, jaguar cichlids, green terror
s, gar
, siamese tigerfish
(datnioides microlepis) and any other semi-aggressive fish that cannot fit in the arowana's mouth.
Australian species are best kept singular in aquaria.
Family Osteoglossidae
o & Teugels, 2003)
‡This species is one of two sometimes called the Australian arowana or Australian bonytongue.
A genetic study shows that the lineage leading to the arapaima and African arowana diverged about 220 million years ago, during the Late Triassic
; the lineage leading to the silver and blackish blue arowanas of South America diverged about 170 million years ago, during the Middle Jurassic
. The lineage leading to the Australian arowanas diverged from that leading to the Asian arowanas about 140 million years ago, during the Early Cretaceous
.
. Other fossils from as far back as the Late Jurassic
or Early Cretaceous
are widely considered to belong to the arowana superorder Osteoglossomorpha
. Osteoglossomorph fossils have been found on all continents except Antarctica. These fossil genera include Brychaetus
, Joffrichthys
, and Phareodus
.
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
bony fish of the family Osteoglossidae, also known as bonytongues. In this family of fishes, the head is bony and the elongate body is covered by large, heavy scales, with a mosaic pattern of canals. The dorsal and the anal fins have soft rays and are long based, while the pectoral and ventral fins are small. The name "bonytongues" is derived from a toothed bone on the floor of the mouth, the "tongue", equipped with teeth that bite against teeth on the roof of the mouth. The fish can obtain oxygen from air by sucking it into the swim bladder
Gas bladder
The swim bladder, gas bladder, fish maw or air bladder is an internal gas-filled organ that contributes to the ability of a fish to control its buoyancy, and thus to stay at the current water depth without having to waste energy in swimming...
, which is lined with capillaries like lung tissue
Lung
The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
. The arowana is an "obligatory air breather".
Classification and distribution
Osteoglossids are basalPrimitive (biology)
Primitive in the sense most relevant to phylogenetics means resembling the first living things and in particular resembling them in the simple nature of their anatomy and behaviour...
(primitive) fish from the lower Tertiary
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
and are placed in the actinopterygii
Actinopterygii
The Actinopterygii or ray-finned fishes constitute a class or sub-class of the bony fishes.The ray-finned fishes are so called because they possess lepidotrichia or "fin rays", their fins being webs of skin supported by bony or horny spines , as opposed to the fleshy, lobed fins that characterize...
d order Osteoglossiformes
Osteoglossiformes
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...
. There are ten described living species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
: three from South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, one from Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, four from Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
, and the remaining two from Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
.
Osteoglossidae is the only exclusively freshwater fish family found on both sides of the Wallace Line
Wallace Line
The Wallace Line separates the ecozones of Asia and Wallacea, a transitional zone between Asia and Australia. West of the line are found organisms related to Asiatic species; to the east, a mixture of species of Asian and Australian origin is present...
. This may be explained by the theroy that Asian arowana
Asian arowana
The Asian arowana comprises several varieties of freshwater fish in the genus Scleropages. Some sources differentiate these varieties into multiple species, while others consider the different strains to belong to a single species, Scleropages formosus...
s (S. formosus) diverged from the Australian Scleropages, S. jardinii and S. leichardti, about 140 million years ago, making it likely that Asian arowanas were carried to Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
on the Indian subcontinent
Indian subcontinent
The Indian subcontinent, also Indian Subcontinent, Indo-Pak Subcontinent or South Asian Subcontinent is a region of the Asian continent on the Indian tectonic plate from the Hindu Kush or Hindu Koh, Himalayas and including the Kuen Lun and Karakoram ranges, forming a land mass which extends...
.
Behavior
Osteoglossids are carnivorousCarnivore
A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging...
, often being specialized surface feeders. They are excellent jumpers; it has been reported that Osteoglossum species have been seen leaping more than 6 feet (almost 2 metres) from the water surface to pick off insects and birds from overhanging branches in South America, hence the nickname "water monkeys". Arowana species typically grow to around 2 to 3 feet in captivity.
Several species of osteoglossid exhibit extensive parental care. They build nests and protect the young after they hatch. All species are mouthbrooder
Mouthbrooder
Mouthbrooding, also known as oral incubation and buccal incubation, is the care given by some groups of animals to their offspring by holding them in the mouth of the parent for extended periods of time. Although mouthbrooding is performed by a variety of different animals, most notably Darwin's...
s, the parents holding sometimes hundreds of eggs in their mouths. The young may make several tentative trips outside the parent's mouth to investigate the surroundings before leaving permanently.These fishes are best kept with live or frozen feed and they easily outgrow the tank within a span of 8-10 months. Always preferred in a large type aquarium of at least 150 gallons.
In the aquarium
Arowanas are solitary fish and only appreciate company while young; adults may show excessive dominance and aggression. Some compatible fish often partnered with this fish are clown knifefish, pacuPacú
Pacu or pacú is the common name of several South American fishes.PACU, Pacu or pacú may also refer to:*Piaractus mesopotamicus , a South American ray-finned fish that is endemic to the Paraguay-Paraná River basin*Tambaqui , known as black pacu, black-finned pacu, giant pacu*Philippine Association...
, oscars, plecostomus
Plecostomus
Hypostomus plecostomus is the scientific name for a type of freshwater tropical Central and South American fish belonging to the family Loricariidae. They are large algae eaters, and to differentiate them from small algae eaters, they are often referred to as plecostomus, often abbreviated as...
, jaguar cichlids, green terror
Green terror
The green terror is a colorful freshwater fish in the cichlid family. The fish originate on the Pacific side of South America in the coastal waters from the Tumbes River in Peru to the Esmeraldas River in Ecuador. Males reach lengths of and females can, too...
s, gar
Gar
In American English the name gar is strictly applied to members of the Lepisosteidae, a family including seven living species of fish in two genera that inhabit fresh, brackish, and occasionally marine, waters of eastern North America, Central America, and the Caribbean islands.-Etymology:In...
, siamese tigerfish
Siamese tigerfish
The Siamese tigerfish is a species of fish from Thailand. It has vertical yellow and black strips running the length of its body, and the dorsal fin has a spiny appearance. .-In the aquarium:...
(datnioides microlepis) and any other semi-aggressive fish that cannot fit in the arowana's mouth.
Australian species are best kept singular in aquaria.
Species
The family contains two subfamilies, Heterotidinae and Osteoglossinae, with all b ut two of the ten extant species being members of the lattr. Species are given with one or more prominent common names. Jardini are the most territorial in the aquarium, exibiting behavior to domFamily Osteoglossidae
- Subfamily Heterotidinae
- Genus ArapaimaArapaimaThe 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:...
- ArapaimaArapaimaThe 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:...
or pirarucu, Arapaima gigas (Cuvier, 1829)
- Arapaima
- Genus Heterotis
- African arowanaAfrican arowanaThe African arowana, Heterotis niloticus, is a member of the arowana family. Despite being called an "Arowana", the African arowana is more closely related to Arapaima gigas, the only other member in the subfamily Heterotidinae...
, Heterotis niloticus (Cuvier, 1829)
- African arowana
- Genus Arapaima
- Subfamily Osteoglossinae
- Genus OsteoglossumOsteoglossumOsteoglossum is a genus of fish in the family Osteoglossidae. The genus contains two species: the silver arowana and the black arowana . They reach almost in length and are restricted to freshwater habitats in tropical South America....
(Cuvier, 1829)- Silver arowanaSilver arowanaThe silver arowana, Osteoglossum bicirrhosum, sometimes spelled arawana, is a freshwater bony fish of the family Osteoglossidae, commonly kept in aquaria...
, Osteoglossum bicirrhosum (Cuvier, 1829) - Black arowanaBlack arowanaThe black arowana, Osteoglossum ferreirai, is a freshwater bony fish of the family Osteoglossidae, commonly kept in aquaria.-Description:...
, Osteoglossum ferreirai Kanazawa,1966
- Silver arowana
- Genus ScleropagesScleropagesSceleropages is a genus of freshwater fishes found in Asia and Australia. Six species are currently recognized. All are carnivorous and have great jumping ability. Most are endangered in the wild to some degree. Scleropages species are highly valued as aquarium fish, particularly by those from...
- Red-tailed golden arowana Scleropages aureus l>(Pouyad, Sudartnatw even a flowerhorn
- Genus Osteoglossum
o & Teugels, 2003)
-
-
- Green arowana or gold crossback arowana, Scleropages formosus (Schlegel & Müller, 1844)
- Gulf saratogaGulf saratogaThe gulf saratoga, Scleropages jardinii, is a freshwater bony fish native to Australia and New Guinea, one of two species of fishes sometimes known as Australian arowanas, the other being the saratoga...
, red saratoga or northern spotted barramundi, Scleropages jardinii ‡ (Saville-Kent, 1892) - Red arowana, super red arowana, or chili red arowana, Scleropages legendrei (Pouyad, Sudarto & Teugels, 2003)
- SaratogaSaratoga (fish)The saratoga, Scleropages leichardti, also known as the spotted bonytongue, spotted saratoga, or southern saratoga, is a freshwater bony fish native to Australia. It belongs to the subfamily Osteoglossinae, or arowanas, a primitive group of teleosts. Like all arowanas, it is a carnivorous...
, silver saratoga or spotted barramundi, Scleropages leichardti ‡ Günther, 1864 - Silver Asian arowana, Scleropages macrocephalus (Pouyad, Sudarto & Teugels, 2003)
-
‡This species is one of two sometimes called the Australian arowana or Australian bonytongue.
A genetic study shows that the lineage leading to the arapaima and African arowana diverged about 220 million years ago, during the Late Triassic
Late Triassic
The Late Triassic is in the geologic timescale the third and final of three epochs of the Triassic period. The corresponding series is known as the Upper Triassic. In the past it was sometimes called the Keuper, after a German lithostratigraphic group that has a roughly corresponding age...
; the lineage leading to the silver and blackish blue arowanas of South America diverged about 170 million years ago, during the Middle Jurassic
Middle Jurassic
The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from 176-161 million years ago. In European lithostratigraphy, rocks of this Middle Jurassic age are called the Dogger....
. The lineage leading to the Australian arowanas diverged from that leading to the Asian arowanas about 140 million years ago, during the Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...
.
Fossil record
At least five extinct genera, known only from fossils, are classified as Osteoglossids; these date back at least as far as the Late CretaceousLate Cretaceous
The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...
. Other fossils from as far back as the Late Jurassic
Late Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 161.2 ± 4.0 to 145.5 ± 4.0 million years ago , which is preserved in Upper Jurassic strata. In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age...
or Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...
are widely considered to belong to the arowana superorder Osteoglossomorpha
Osteoglossomorpha
Osteoglossomorpha is a group of bony fish in the Teleostei.-Notable members:A notable member is the Arapaima , the largest freshwater fish in South America and one of the very largest bony fishes alive. Other notable members include the bizarre freshwater elephantfishes .-Systematics:Most...
. Osteoglossomorph fossils have been found on all continents except Antarctica. These fossil genera include Brychaetus
Brychaetus
Brychaetus is an extinct genus of prehistoric bony fish, known from the Late Cretaceous to the Paleocene. It contains a single species, Brychaetus muelleri Its fossils have been found in Europe, North America, and northern Africa. This freshwater fish had very long, blunt teeth.-See also:*...
, Joffrichthys
Joffrichthys
Joffrichthys is a genus of prehistoric bony fish. This North American genus includes two species, J. symmetropterus and J. triangulpterus. The latter species is known from the Paleocene of the Sentinel Butte Formation of North Dakota.-See also:...
, and Phareodus
Phareodus
Phareodus is a genus of freshwater fish from the Eocene to the Oligocene of Australia and North America.This genus includes at least four species, P. testis and P. encaustus of North America, P. muelleri of Europe, and P. queenslandicus of Australia...
.