Oxydoras
Encyclopedia
Oxydoras is a genus
of catfish
es (order
Siluriformes) of the family
Doradidae
. This genus includes three species, O. kneri, O. niger, and O. sifontesi.
basin. O. niger is found in the Amazon
, São Francisco
, and Essequibo River
basins, and is also possibly in the Orinoco River basin. O. sifontesi inhabits the Orinoco River basin.
s (20 lb
). O. niger gets even heavier, with a maximum published weight of 11.0 kilogram
s (24 lb).
s, crustacean
s, mollusks, other invertebrate
s and some vegetable material. O. niger feeds on detritus
, chironomid
and ephemeropteran larva
e, and crustaceans.
O. niger occurs over mud in streams and lakes. It is known from temperatures ranging from 24–29.8°C (75–85.6°F), pH
range of 5–9, and an alkalinity
range of 42–142. O. niger is known to form schools.
fish species. In the hobby, it goes by many names, including black talking catfish, mother of snails catfish, ripsaw catfish, and black doradid. This species grows to a large size and are often bought by unsuspecting aquarists when small. They will rapidly outgrow smaller tanks, so the aquarium should be as large as possible. O. niger is especially light shy and should be provided with sheltered areas to hide. These fish are peaceful, although fish that are too small are risky. This specices readily accepts prepared foods
. O. niger has not been bred under aquarium conditions.
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...
of catfish
Catfish
Catfishes are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...
es (order
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...
Siluriformes) of the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Doradidae
Doradidae
Doradidae is a family of catfishes also known as thorny catfishes or talking catfishes. These fish are native to South America, primarily in Brazil, Peru, and the Guianas.Doradids are omnivorous.-Taxonomy:...
. This genus includes three species, O. kneri, O. niger, and O. sifontesi.
Distribution
O. kneri originates from Paraná RiverParaná River
The Paraná River is a river in south Central South America, running through Brazil, Paraguay and Argentina for some . It is second in length only to the Amazon River among South American rivers. The name Paraná is an abbreviation of the phrase "para rehe onáva", which comes from the Tupi language...
basin. O. niger is found in the Amazon
Amazon River
The Amazon of South America is the second longest river in the world and by far the largest by waterflow with an average discharge greater than the next seven largest rivers combined...
, São Francisco
São Francisco River
The São Francisco is a river in Brazil. With a length of , it is the longest river that runs entirely in Brazilian territory, and the fourth longest in South America and overall in Brazil...
, and Essequibo River
Essequibo River
The Esequibo River is the largest river in Guyana, and the largest river between the Orinoco and Amazon. Rising in the Acarai Mountains near the Brazil-Guyana border, the Essequibo flows to the north for 1,010 km through forest and savanna into the Atlantic Ocean.-Geography:There are countless...
basins, and is also possibly in the Orinoco River basin. O. sifontesi inhabits the Orinoco River basin.
Description
Oxydoras species are relatively large, reaching between 70–100 centimetres (28–40 in) in length. O. kneri has a maximum published weight of 9,000 gramGram
The gram is a metric system unit of mass....
s (20 lb
Pound (mass)
The pound or pound-mass is a unit of mass used in the Imperial, United States customary and other systems of measurement...
). O. niger gets even heavier, with a maximum published weight of 11.0 kilogram
Kilogram
The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...
s (24 lb).
Ecology
O. kneri is omnivorous, feeding mainly on insectInsect
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, crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, mollusks, other invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s and some vegetable material. O. niger feeds on detritus
Detritus
Detritus is a biological term used to describe dead or waste organic material.Detritus may also refer to:* Detritus , a geological term used to describe the particles of rock produced by weathering...
, chironomid
Chironomidae
Chironomidae are a family of nematoceran flies with a global distribution. They are closely related to the Ceratopogonidae, Simuliidae, and Thaumaleidae...
and ephemeropteran larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e, and crustaceans.
O. niger occurs over mud in streams and lakes. It is known from temperatures ranging from 24–29.8°C (75–85.6°F), 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...
range of 5–9, and an alkalinity
Alkalinity
Alkalinity or AT measures the ability of a solution to neutralize acids to the equivalence point of carbonate or bicarbonate. The alkalinity is equal to the stoichiometric sum of the bases in solution...
range of 42–142. O. niger is known to form schools.
In the aquarium
O. niger is a popular 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...
fish species. In the hobby, it goes by many names, including black talking catfish, mother of snails catfish, ripsaw catfish, and black doradid. This species grows to a large size and are often bought by unsuspecting aquarists when small. They will rapidly outgrow smaller tanks, so the aquarium should be as large as possible. O. niger is especially light shy and should be provided with sheltered areas to hide. These fish are peaceful, although fish that are too small are risky. This specices readily accepts prepared foods
Fish food
Aquarium fish feed is plant or animal material intended for consumption by pet fish kept in aquariums or ponds. Fish foods normally contain macro nutrients, trace elements and vitamins necessary to keep captive fish in good health. Approximately 80% of fishkeeping hobbyists feed their fish...
. O. niger has not been bred under aquarium conditions.