The freshwater butterflyfish or African butterflyfish, ''Pantodon buchholzi'', is the only
extant
Extant is the opposite of the word extinct. It may refer to:
* Extant hereditary titles
* Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English
* Extant taxon, a taxon which is not extinct, ...
species in the family
Pantodontidae
Pantodontidae is a family of ray-finned fish in the order Osteoglossiformes. It contains the living freshwater butterflyfish (''Pantodon buchholzi'') of Africa, as well as five extinct species from the Late Cretaceous ( Cenomanian) of Lebanon. ...
within the order
Osteoglossiformes
Osteoglossiformes (Greek: "bony tongues") is a relatively primitive order of ray-finned fish that contains two sub-orders, the Osteoglossoidei and the Notopteroidei. All of at least 245 living species inhabit freshwater. They are found in South ...
. It is not closely related to saltwater
butterflyfish
The butterflyfish are a group of conspicuous tropical marine fish of the family Chaetodontidae; the bannerfish and coralfish are also included in this group. The approximately 129 species in 12 genera are found mostly on the reefs of the Atlant ...
es.
Description and habits
Freshwater butterfly fish are small, no more than in length, with very large
pectoral fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...
s. It has a large and well-vascularized
swim bladder
The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled Organ (anatomy), organ that contributes to the ability of many bony fish (but not cartilaginous fish) to control their buoyancy, and thus to stay at their curren ...
, enabling it to breathe air at the surface of the water. It is carnivorous, feeding primarily on aquatic
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...
s and smaller fishes.
The freshwater butterflyfish is a specialized surface hunter. Its eyes are constantly trained to the surface and its upturned mouth is specifically adapted to capture small prey along the water's surface. If enough speed is built up in the water, a butterflyfish can jump and
glide
Glide may refer to:
* Gliding flight, to fly without thrust
Computing
*Glide API, a 3D graphics interface
*Glide OS, a web desktop
*Glide (software), an instant video messenger
*Glide, a molecular docking software by Schrödinger (company), Schrà ...
a small distance above the surface to avoid predation. It also wiggles its pectoral fins as it glides, with the help of specialized, enlarged pectoral muscles, the ability which earned the fish its common name.
[Berra, Tim M. (2001). ''Freshwater Fish Distribution''. San Diego: Academic Press. ]
When freshwater butterflyfish spawn, they produce a mass of large floating eggs at the surface. Fertilisation is believed to be internal. Eggs hatch in about seven days.
Distribution
Freshwater butterflyfish are found in the slightly acidic, standing bodies of water in West Africa. They require a year-round temperature of . They are found in slow- to no-current areas with high amounts of surface foliage for cover. They are commonly seen in
Lake Chad
Lake Chad (french: Lac Tchad) is a historically large, shallow, endorheic lake in Central Africa, which has varied in size over the centuries. According to the ''Global Resource Information Database'' of the United Nations Environment Programme, ...
, the
Congo Basin
The Congo Basin (french: Bassin du Congo) is the sedimentary basin of the Congo River. The Congo Basin is located in Central Africa, in a region known as west equatorial Africa. The Congo Basin region is sometimes known simply as the Congo. It con ...
, throughout lower
Niger
)
, official_languages =
, languages_type = National languages[Cameroon
Cameroon (; french: Cameroun, ff, Kamerun), officially the Republic of Cameroon (french: République du Cameroun, links=no), is a country in west-central Africa. It is bordered by Nigeria to the west and north; Chad to the northeast; the C ...](_blank)
,
Ogooue, and upper
Zambezi
The Zambezi River (also spelled Zambeze and Zambesi) is the fourth-longest river in Africa, the longest east-flowing river in Africa and the largest flowing into the Indian Ocean from Africa. Its drainage basin covers , slightly less than hal ...
. They have also been seen in the
Niger Delta
The Niger Delta is the delta of the Niger River sitting directly on the Gulf of Guinea on the Atlantic Ocean in Nigeria. It is located within nine coastal southern Nigerian states, which include: all six states from the South South geopolitical ...
, lower Ogooue, and in the lower
Cross River.
In the aquarium
Freshwater butterflyfish are kept in large aquaria, although a single specimen should be kept as the only top-level fish, as they can be aggressive to their own kind and others at surface level. The tops of the tanks must be tightly closed because of their jumping habits. They do better in a tank with live plants, especially ones that float near the surface, providing hiding places to reduce stress. They require a
pH of 6.9–7.1, and a
KH of 1–10. In aquaria, freshwater butterflyfish can grow to 5 in. They should not be kept with fin-eating or aggressive fish. They eat any fish small enough to fit in their mouths, so they should be maintained with bottom-dwelling fish or top- and mid-dwelling fish too large in size to be bothered by them. They generally will not eat prepared food, and do best on a diet of live or possibly canned crickets and other insects, as well as live, gut-loaded feeder fish (
goldfish
The goldfish (''Carassius auratus'') is a freshwater fish in the family Cyprinidae of order Cypriniformes. It is commonly kept as a pet in indoor aquariums, and is one of the most popular aquarium fish. Goldfish released into the wild have ...
should be avoided). They prefer still water, so filtration should not be too powerful.
See also
*
Flying and gliding animals
A number of animals are capable of aerial locomotion, either by powered flight or by gliding. This trait has appeared by evolution many times, without any single common ancestor. Flight has evolved at least four times in separate animals: inse ...
*
List of freshwater aquarium fish species
A vast number of aquatic species have successfully adapted to live in the freshwater aquarium. This list gives some examples of the most common species found in home aquariums.
Catfish
Characins and other characiformes
...
References
Bibliography
*
*
*
Innes, Dr William T., ''Exotic Aquarium Fishes'', Innes Publishing Co. Philadelphia, 1935
{{Taxonbar, from=Q260106
Osteoglossiformes
Freshwater fish of Africa
Fish described in 1877
Taxa named by Wilhelm Peters