The biara (''Rhaphiodon vulpinus'') is a South American
piscivorous
A piscivore () is a carnivorous animal that primarily eats fish. Fish were the diet of early tetrapod evolution (via water-bound amphibians during the Devonian period); insectivory came next; then in time, the more terrestrially adapted rept ...
fish
A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...
in the
dogtooth characin family. It belongs to the
monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...
genus ''Rhaphiodon'', although some minor differences in
morphometrics and colour are known from across its large range.
It is found in the
Amazon
Amazon most often refers to:
* Amazon River, in South America
* Amazon rainforest, a rainforest covering most of the Amazon basin
* Amazon (company), an American multinational technology company
* Amazons, a tribe of female warriors in Greek myth ...
,
Orinoco
The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers approximately 1 million km2, with 65% of it in Venezuela and 35% in Colombia. It is the List of rivers by discharge, f ...
, and
Río de la Plata Basin
The Río de la Plata basin (, ), more often called the River Plate basin in scholarly writings, sometimes called the Platine basin or Platine region, is the Hydrography, hydrographical area in South America that drains to the Río de la Plata. I ...
s, as well as rivers of the
Guianas
The Guianas, also spelled Guyanas or Guayanas, are a geographical region in north-eastern South America. Strictly, the term refers to the three Guianas: Guyana, Suriname, and French Guiana, formerly British Guiana, British, Surinam (Dutch colo ...
.
It occurs in a wide range of freshwater habitats such as main river channels,
flooded forests, lakes and reservoirs.
Some populations are migratory.[
]
Description
It reaches up to in weight.[ Although it reportedly can reach up to in ]standard length
Fish measurement is the measuring of individual fish and various parts of fish anatomy, their anatomies, for data used in many areas of ichthyology, including Taxonomy (biology), taxonomy and fishery biology.
Overall length
Standard length (SL) is ...
,[ the largest confirmed were 63-64 cm (about 2 ft 1 in)] Like other dogtooth characins, the biara has very long pointed canine teeth, but it is easily separated from its relatives by its very elongated and streamlined body shape.[
]
Diet
Like its relatives, the biara feeds almost entirely on other fish, which are speared by the long canines.[ In a study of the stomach content of 100 biaras, the majority were empty. The remaining had prey fish that were 30–50% of the length of the biara itself, and only a single contained another prey type, a ]mayfly
Mayflies (also known as shadflies or fishflies in Canada and the upper Midwestern United States, as Canadian soldiers in the American Great Lakes region, and as up-winged flies in the United Kingdom) are aquatic insects belonging to the orde ...
larvae.[
]
Reproduction
In a study observing the reproductive biology of the biara species in the Tocantins River of Brazil, it was found that the prime reproductive period takes place in November. The high-water conditions of the environment correlate to the increase of reproductive rate.
Aquarium trade
The biara occasionally makes its way into the aquarium trade, but it requires a very large tank.[
]
References
Cynodontidae
Fish of South America
Taxa named by Johann Baptist von Spix
Taxa named by Louis Agassiz
Fish described in 1829
{{Characiformes-stub