Gray bichir
Encyclopedia
The Senegal Bichir, Polypterus senegalus, also known as the Gray Bichir and Cuvier's Bichir, is sometimes called the "dinosaur eel" at many local pet chains - a misnomer, as the creature is not an eel
. It is a fish, a prototypical species
of the Polypterus
genus
, meaning most of its features are held across the genus.
runs along most of the body until it meets the caudal fin. The pectoral fins attach just behind and below the gill
openings and are the primary means of locomotion, providing a slow, graceful appearance. P. senegalus is smaller than its brethren, reaching about 35.5 cm (14").
The head is small and lizard-like with a gaping mouth and small eye
s on either side. Since its eyesight is poor the bichir primarily hunts by smell. External nostril
s protrude from the nose of the fish to enable this.
The fish has a pair of primitive lung
s instead of a swim bladder, allowing it to periodically gulp air from the surface of the water. In the aquarium bichirs can be observed dashing to the surface for this purpose. Provided the skin remains moist, the creature can remain out of the water for near indefinite periods of time.
This bichir's skin serves as a particularly effective armor.
P. senegalus senegalus
Maximum size:
In wild: 20"
Captivity: 12"
Description: Uniform brownish-grey to olive colour on dorsal surface, ventral surface whitish. No banding on adults, very young juveniles show three horizontal bands. Upper jaw slightly longer than lower jaw. 8-11 dorsal finlets.
P. senegalus meridionalis
Maximum size:
In the wild: 28"
Captivity: 14"
Description: Uniform olive-grey colouration. 9-10 dorsal spines. Jaws appromiately equal length. P. senegalus meridionalis is also thought to be a regional variant of Polypterus senegalus senegalus
and in captivity
will take any live or dead animal that can be swallowed or broken apart and then swallowed. The only thing preventing a bichir from emptying an aquarium
of smaller fish is its speed; the pectoral fins only allow for slow cruising, and while it can achieve amazing bursts of speed, it can't catch fish of average speed. Given enough time, any fish that can fit in the bichir's mouth will be eaten; this fish should not be kept with any other fish smaller than three inches.
Bichirs require a lot of floor space; the height of the tank doesn't matter. You should note that since these specimens can grow over 12" long, they should be kept in a 50+ gallon
tank. There should be a gap of air in the tank allowing the bichir to gulp air, the tank can't be full of water. Bichirs are escape artists. Without a secure lid on an aquarium, the fish will eventually escape, and go quite a long distance before drying out and dying.
Bichirs will also take dry foods such as shrimp
pellets and occasionally cichlid pellets as well as flakes. They will readily accept frozen bloodworms, blackworms, and other frozen foods. They will also accept earthworms. Take care to wash the worms after collecting them, and make sure no pesticide
s have been recently spread.
Eel
Eels are an order of fish, which consists of four suborders, 20 families, 111 genera and approximately 800 species. Most eels are predators...
. It is a fish, a prototypical 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...
of the Polypterus
Polypterus
Polypterus is a genus of freshwater fish in the bichir family of order Polypteriformes. The type species is the Nile bichir . Fishes in this genus live in various areas in Africa...
genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
, meaning most of its features are held across the genus.
Appearance
The body is long and about as deep as it is wide. A serrated dorsal finDorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
runs along most of the body until it meets the caudal fin. The pectoral fins attach just behind and below the gill
Gill
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
openings and are the primary means of locomotion, providing a slow, graceful appearance. P. senegalus is smaller than its brethren, reaching about 35.5 cm (14").
The head is small and lizard-like with a gaping mouth and small eye
Eye
Eyes are organs that detect light and convert it into electro-chemical impulses in neurons. The simplest photoreceptors in conscious vision connect light to movement...
s on either side. Since its eyesight is poor the bichir primarily hunts by smell. External nostril
Nostril
A nostril is one of the two channels of the nose, from the point where they bifurcate to the external opening. In birds and mammals, they contain branched bones or cartilages called turbinates, whose function is to warm air on inhalation and remove moisture on exhalation...
s protrude from the nose of the fish to enable this.
The fish has a pair of primitive lung
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...
s instead of a swim bladder, allowing it to periodically gulp air from the surface of the water. In the aquarium bichirs can be observed dashing to the surface for this purpose. Provided the skin remains moist, the creature can remain out of the water for near indefinite periods of time.
This bichir's skin serves as a particularly effective armor.
Subspecies
There are believed to be three subspecies of Polypterus senegalus, these are Polypterus senegalus senegalus, Polypterus senegalus meridionalis and a further unnamed species.P. senegalus senegalus
Maximum size:
In wild: 20"
Captivity: 12"
Description: Uniform brownish-grey to olive colour on dorsal surface, ventral surface whitish. No banding on adults, very young juveniles show three horizontal bands. Upper jaw slightly longer than lower jaw. 8-11 dorsal finlets.
P. senegalus meridionalis
Maximum size:
In the wild: 28"
Captivity: 14"
Description: Uniform olive-grey colouration. 9-10 dorsal spines. Jaws appromiately equal length. P. senegalus meridionalis is also thought to be a regional variant of Polypterus senegalus senegalus
Captivity
Bichirs are predatory fishFish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
and in captivity
Captivity (animal)
Animals that live under human care are in captivity. Captivity can be used as a generalizing term to describe the keeping of either domesticated animals or wild animals. This may include for example farms, private homes and zoos...
will take any live or dead animal that can be swallowed or broken apart and then swallowed. The only thing preventing a bichir from emptying an aquarium
Aquarium
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 smaller fish is its speed; the pectoral fins only allow for slow cruising, and while it can achieve amazing bursts of speed, it can't catch fish of average speed. Given enough time, any fish that can fit in the bichir's mouth will be eaten; this fish should not be kept with any other fish smaller than three inches.
Bichirs require a lot of floor space; the height of the tank doesn't matter. You should note that since these specimens can grow over 12" long, they should be kept in a 50+ gallon
Gallon
The gallon is a measure of volume. Historically it has had many different definitions, but there are three definitions in current use: the imperial gallon which is used in the United Kingdom and semi-officially within Canada, the United States liquid gallon and the lesser used United States dry...
tank. There should be a gap of air in the tank allowing the bichir to gulp air, the tank can't be full of water. Bichirs are escape artists. Without a secure lid on an aquarium, the fish will eventually escape, and go quite a long distance before drying out and dying.
Bichirs will also take dry foods such as shrimp
Shrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
pellets and occasionally cichlid pellets as well as flakes. They will readily accept frozen bloodworms, blackworms, and other frozen foods. They will also accept earthworms. Take care to wash the worms after collecting them, and make sure no pesticide
Pesticide
Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...
s have been recently spread.
External links
- Fish scales may point to armor of the future
- Dinosaur eel inspires bulletproof armor
- Care information for Senegal Bichir at The Aquarium Wiki