Freshwater butterflyfish
Encyclopedia
The freshwater butterflyfish or African butterflyfish, Pantodon buchholzi, is the only species in the family Pantodontidae within the Order Osteoglossiformes
. It is not closely related to saltwater butterflyfish
es.
, enabling it to breathe air at the surface of the water. They are carnivorous, feeding primarily on aquatic insect
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 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.
When freshwater butterflyfish spawn, they produce a mass of large floating eggs at the surface. Fertilisation is believed to be internal. Eggs hatch in approximately seven days.
, the Congo Basin
, throughout Lower Niger
, Cameroon
, Ogooue, and Upper Zambezi
. They have also been seen in the Niger
Delta, Lower Ogun, and in the Lower Cross River
.
of at least 20 gallons (75.7 l), although a single specimen could be maintained in an aquarium as small as 10 gallons (37.9 l)if no other fish are kept with it. The tops of the tanks have to be tightly closed because of their jumping habits. They also prefer 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 4 inches. Freshwater Butterflyfish should not be kept with fin-eating or aggressive fishes. They are aggressive towards other top-dwelling fishes and will 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 it. 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 should be avoided). They prefer still water, so filtration should not be too powerful.
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...
. It is not closely related to saltwater butterflyfish
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. Found mostly on the reefs of the Atlantic, Indian and Pacific Oceans, there are approximately 120 species in 10 genera...
es.
Description and habits
Freshwater butterfly fish are small, no more than 13 centimetres (5.1 in) in length, with very large pectoral fins. It has a large and well-vascularized swim bladderGas 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...
, enabling it to breathe air at the surface of the water. They are carnivorous, feeding primarily on aquatic insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
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 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.
When freshwater butterflyfish spawn, they produce a mass of large floating eggs at the surface. Fertilisation is believed to be internal. Eggs hatch in approximately 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 73-86°F. Butterflyfish are found in slow to no current areas with high amounts of surface foliage for cover. They are commonly seen in Lake ChadLake Chad
Lake Chad is a historically large, shallow, endorheic lake in Africa, whose size has varied over the centuries. According to the Global Resource Information Database of the United Nations Environment Programme, it shrank as much as 95% from about 1963 to 1998; yet it also states that "the 2007 ...
, the Congo Basin
Congo Basin
The Congo Basin is the sedimentary basin that is the drainage of the Congo River of west equatorial Africa. The basin begins in the highlands of the East African Rift system with input from the Chambeshi River, the Uele and Ubangi Rivers in the upper reaches and the Lualaba River draining wetlands...
, throughout Lower Niger
Niger
Niger , officially named the Republic of Niger, is a landlocked country in Western Africa, named after the Niger River. It borders Nigeria and Benin to the south, Burkina Faso and Mali to the west, Algeria and Libya to the north and Chad to the east...
, Cameroon
Cameroon
Cameroon, officially the Republic of Cameroon , is a country in west Central Africa. It is bordered by Nigeria to the west; Chad to the northeast; the Central African Republic to the east; and Equatorial Guinea, Gabon, and the Republic of the Congo to the south. Cameroon's coastline lies on the...
, Ogooue, and Upper Zambezi
Zambezi
The Zambezi is the fourth-longest river in Africa, and the largest flowing into the Indian Ocean from Africa. The area of its basin is , slightly less than half that of the Nile...
. They have also been seen in the Niger
Niger
Niger , officially named the Republic of Niger, is a landlocked country in Western Africa, named after the Niger River. It borders Nigeria and Benin to the south, Burkina Faso and Mali to the west, Algeria and Libya to the north and Chad to the east...
Delta, Lower Ogun, and in the Lower Cross River
Cross River (Nigeria)
Cross River is the main river in southeastern Nigeria and gives its name to Cross River State.It originates in Cameroon, where it takes the name of the Manyu River....
.
In the aquarium
Freshwater Butterflyfish are kept as pets in an aquariumAquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
of at least 20 gallons (75.7 l), although a single specimen could be maintained in an aquarium as small as 10 gallons (37.9 l)if no other fish are kept with it. The tops of the tanks have to be tightly closed because of their jumping habits. They also prefer a tank with live plants, especially ones that float near the surface, providing hiding places to reduce stress
Stress (medicine)
Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...
. They require a pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
of 6.9-7.1, and a KH of 1-10. In aquaria, Freshwater Butterflyfish can grow to 4 inches. Freshwater Butterflyfish should not be kept with fin-eating or aggressive fishes. They are aggressive towards other top-dwelling fishes and will 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 it. 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 should be avoided). They prefer still water, so filtration should not be too powerful.