''Brachyplatystoma'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

catfish Catfish (or catfishes; order Siluriformes or Nematognathi) 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 three largest species alive, ...

from the family Pimelodidae. As the occasionally used common name goliath catfishes indicates, this genus includes some of the largest species of catfish, including the

piraíba ''Brachyplatystoma filamentosum'', the piraíba or kumakuma, is a species of large catfish of the family Pimelodidae and genus Brachyplatystoma that is native to Amazon and Orinoco River basins and fluvials in Guianas and northeastern Brazil. Di ...

, ''B. filamentosum'', which reaches up to the region of in length. ''Brachyplatystoma'' are found in the

Amazon Amazon most often refers to: * Amazons, a tribe of female warriors in Greek mythology * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon River, in South America * Amazon (company), an American multinational technolog ...

and

Orinoco The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers , with 76.3 percent of it in Venezuela and the remainder in Colombia. It is the fourth largest river in the wor ...

basins, and other tropical freshwater and

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estua ...

habitats in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sou ...

. Some species are migratory. These fish are important as food fish and, to some extent,

aquarium An aquarium (plural: ''aquariums'' or ''aquaria'') is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aq ...

fish.

Taxonomy

''Brachyplatystoma'' originates from

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

''brachys'', ''platys'', and ''stoma'', which mean ''short'', ''flat'', and ''mouth'' respectively. This genus was described in 1862 by

Pieter Bleeker Pieter Bleeker (10 July 1819 – 24 January 1878) was a Dutch medical doctor, ichthyologist, and herpetologist. He was famous for the ''Atlas Ichthyologique des Indes Orientales Néêrlandaises'', his monumental work on the fishes of East Asia ...

. The type species is ''B. vaillantii''. The subgenus ''Malacobagrus'' is applied to ''B. capapretum'', ''B. filamentosum'', ''B. rousseauxii'', and the

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

species ''B. promagdalena'', which only is known from

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

remains. ''Brachyplatystoma'' and its

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 "unispe ...

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

'' Platynematichthys'' are the only genera in the tribe Brachyplatystomatini. These two genera are characterized by two synapomorphies; these include a

gas bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled organ that contributes to the ability of many bony fish (but not cartilaginous fish) to control their buoyancy, and thus to stay at their current water depth wit ...

divided into an

anterior Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Th ...

portion and a triangular posterior portion, as well as a

ventral Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

crest under the

cleithrum The cleithrum (plural cleithra) is a membrane bone which first appears as part of the skeleton in primitive bony fish, where it runs vertically along the scapula. Its name is derived from Greek κλειθρον = "key (lock)", by analogy with "cla ...

, the main bone supporting the

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 se ...

s. The genus ''Brachyplatystoma'' was previously not

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gr ...

; to correct this, the genera ''Merodontotus'' and ''Goslinia'' are now both included under ''Brachyplatysoma''. Furthermore, a new species was described in 2005, which brings the species count to seven

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. ''B. capapretum'' is sister to ''B. filamentosum''. ''B. flavicans'' is not actually a species of ''Brachyplatystoma''; this name is a commonly used synonym of '' Zungaro zungaro''.

Anatomy and appearance

''Brachyplatystoma'' all exhibit long maxillary barbels that extend past the

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...

in all species, but may even extend to the

caudal 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 se ...

. The caudal fin of adult ''Brachyplatystoma'' fish is moderately to deeply forked. ''Brachyplatystoma'' have specialized pelagic young with greatly elongated barbels and fin filaments, and strongly ornamented pectoral spines. This genus is characterized by two

synapomorphies In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to ha ...

. One of these is modified jaw muscles. The other, more obvious trait, is only found in juveniles and subadults, in which the upper and lower

rays Ray may refer to: Fish * Ray (fish), any cartilaginous fish of the superorder Batoidea * Ray (fish fin anatomy), a bony or horny spine on a fin Science and mathematics * Ray (geometry), half of a line proceeding from an initial point * Ray (gra ...

of the

are extended into long filaments. ''B. vaillantii'' is the

sister species In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

to all other ''Brachyplatystoma'', marked by differences in the

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...

, jaw, and other bones. The subgenus ''Malacobagrus'' is characterized by their derived

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

Weberian apparatus The Weberian apparatus is an anatomical structure that connects the swim bladder to the auditory system in fishes belonging to the superorder Ostariophysi. When it is fully developed in adult fish, the elements of the apparatus are sometimes co ...

, a subquadrangular

gill cover The operculum is a series of bones found in bony fish and chimaeras that serves as a facial support structure and a protective covering for the gills; it is also used for respiration and feeding. Anatomy The opercular series contains four bon ...

(as opposed to triangular in other species), and pectoral spine. As mentioned, one of the characteristics of this genus are extended caudal fin filaments and very long barbels on younger fish. In most of the species these filaments are not as elongated in adults, though they are retained in ''B. tigrinum'', ''B. juruense'', and ''B. platynemum'', and the filaments are often severed by other fish or in accidents. Many ''Brachyplatystoma'' exhibit

countershading Countershading, or Thayer's law, is a method of camouflage in which an animal's coloration is darker on the top or upper side and lighter on the underside of the body. This pattern is found in many species of mammals, reptiles, birds, fish ...

, in which the

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal c ...

surface is darker, and then fades to a lighter belly. In most species, this is consistent throughout life, though there are some exceptions. Juvenile ''B. capapretum'' and ''B. filamentosum'' exhibit dorsal and lateral spots which mostly disappear in the adult form. Juvenile ''B. juruense'' and ''B. tigrinum'' exhibit lateral spots that expand to form vertical stripes as the fish matures. ''B. capapretum'', described in 2005, was previously misidentified as ''B. filamentosum''. These two species are closely related. However, these species differ in

premaxillary The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has b ...

dentition, juvenile and adult coloration, and adult maxillary barbel length and caudal fin shape. These two species exhibit spotted juvenile stages, though in ''B. capapretum'' these spots are much larger than the eye, while in ''B. filamentosum'' these spots are about the same size as the eye. Also, the cross section of the

caudal peduncle 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 see ...

is rounded in these two species, as opposed to a deeper, thinner cross section in other ''Brachyplatystoma'' species. The adult ''B. capapretum'' has a very dark or even black dorsum (its species name is derived from

Portuguese Portuguese may refer to: * anything of, from, or related to the country and nation of Portugal ** Portuguese cuisine, traditional foods ** Portuguese language, a Romance language *** Portuguese dialects, variants of the Portuguese language ** Portu ...

which means ''black cape''), as opposed to the lighter dorsal surface of ''B. filamentosum''. ''Brachyplatystoma'' includes some of the largest species of

ian catfish, including the Piraíba, ''B. filamentosum'', which reaches up to about in length and in weight. Even the most modest species reach about 60 cm (23 inches) The other species range in size from about . ''B. filamentosum'' and ''B. rousseauxii'' have a mysterious "

milk Milk is a white liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals (including breastfed human infants) before they are able to digest solid food. Immune factors and immune-modulat ...

gland In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland). Structure De ...

at the anterior upper part of their pectoral fins. Its function is unknown, but in

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the ...

this fish is known as ''lechero'', which means ''milkman''. The world record recognized by IGFA for ''Brachyplatystoma filamentosum'' belongs to the Brazilian, Jorge Masullo de Aguiar with 155 kg. Pimelodidae Brachyplatystoma sp (juv)

Distribution and habitat

Fish of this genus are found in the

, and

The Guyanas The Guianas, sometimes called by the Spanish loan-word ''Guayanas'' (''Las Guayanas''), is a region in north-eastern South America which includes the following three territories: * French Guiana, an overseas department and region of France * ...

. The genus does not occur west or north of the

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

or in the

Venezuelan Coastal Range The Venezuelan Coastal Range ( es, Cordillera de la Costa or ), also known as Venezuelan Caribbean Mountain System ( es, Sistema Montañoso Caribe) is a mountain range system and one of the eight natural regions of Venezuela, that runs along the ...

. These fish generally inhabit areas that have a soft substrate, such as mud or sand. The fossil catfish ''B. promagdalena'' has been found in

in an area now drained by the

Magdalena River The Magdalena River ( es, Río Magdalena, ; less commonly ) is the main river of Colombia, flowing northward about through the western half of the country. It takes its name from the biblical figure Mary Magdalene. It is navigable through much of ...

, where ''Brachyplatystoma'' species are currently absent; during the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

, this area had been drained by the Amazon and Orinoco system.

Ecology

These fish are mainly piscivorous. Stomach contents of ''B. filamentosum'' have been claimed to sometimes contain

monkey Monkey is a common name that may refer to most mammals of the infraorder Simiiformes, also known as the simians. Traditionally, all animals in the group now known as simians are counted as monkeys except the apes, which constitutes an incomple ...

s and it may even prey on humans. Some of the species of ''Brachyplatystoma'' migrate long distances for

reproduction Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual or ...

. This is known in ''B. vaillantii'', ''B. platynemum'', and ''B. rousseauxii'', but data about the migratory habits of other species are scant. This migration is associated with white-water rivers, as black water does not contain enough food for migrating Pimelodids. Maturation is timed to the increase in river level. Migration begins as the river level begins to rise with the coming of the

rainy season The rainy season is the time of year when most of a region's average annual rainfall occurs. Rainy Season may also refer to: * ''Rainy Season'' (short story), a 1989 short horror story by Stephen King * "Rainy Season", a 2018 song by Monni * '' ...

. ''B. rousseauxii'' has the longest reproductive migration of any freshwater fish; from the mouth of the

, migration may stretch , a trip which may last five to six months, before they spawn in the western tributaries of the Amazon. It is hypothesized that ''B. rousseauxii'' is homing, that is, it will return to the tributary in which it was born. Before spawning, the

stomach The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...

s of these fish are empty, due to high digestive efficiency. The young are carried downstream until they reach

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environme ...

. Juveniles and subadults are commonly found in these habitats. They may even live in brackish waters at this time. They will live in these estuaries and river mouths for about three years here before entering the lower reaches of the river. At this still immature stage, they may form groups or school. This is the first record of young, migratory fish in the Amazon basin.

Relationship to humans

''Brachyplatystoma'' are important food fish. In the

Amazon Basin The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries of Boli ...

, thousands of

metric ton The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton (United States ...

s of fish from this genus are caught for both local consumption as well as exportation. These fish are usually caught with the use of longlines or drift nets. They are also captured by

harpoon A harpoon is a long spear-like instrument and tool used in fishing, whaling, sealing, and other marine hunting to catch and injure large fish or marine mammals such as seals and whales. It accomplishes this task by impaling the target ani ...

as well as

rope A rope is a group of yarns, plies, fibres, or strands that are twisted or braided together into a larger and stronger form. Ropes have tensile strength and so can be used for dragging and lifting. Rope is thicker and stronger than similarl ...

s with large

fish hook A fish hook or fishhook, formerly also called angle (from Old English ''angol'' and Proto-Germanic ''*angulaz''), is a hook used to catch fish either by piercing and embedding onto the inside of the fish mouth (angling) or, more rarely, by impal ...

s at the end. ''B. filamentosum'' is a major fishery, and ''B. rousseauxii'' has become the most important species in the Amazon River basin. ''B. rousseauxii'' and ''B. vaillantii'' constitute a significant percentage of Amazonian food fish. Based on a review by

IBAMA Brazilian Institute of the Environment and Renewable Natural Resources ( pt, Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis, IBAMA) is the Brazilian Ministry of the Environment's administrative arm. IBAMA supports anti-d ...

, ''B. vaillantii'' was by far the most caught fish by weight in the

Brazilian Amazon Brazilian commonly refers to: * Something of, from or relating to Brazil * Brazilian Portuguese, the dialect of the Portuguese language used mostly in Brazil * Brazilians, the people (citizens) of Brazil, or of Brazilian descent Brazilian may als ...

in 1998, ''B. rousseauxii'' the fourth most caught and ''B. filamentosum'' the sixth (''

Semaprochilodus ''Semaprochilodus'' is a genus of South American freshwater fish in the family Prochilodontidae. They have sometimes been included in the genus '' Prochilodus'' instead. Of the six species, three are from the Amazon Basin, two from the Orinoco ...

'' spp. second, ''

Prochilodus nigricans ''Prochilodus nigricans'', or black prochilodus, is a species of prochilodontid fish from the Amazon Basin in South America. It supports major fisheries; according to IBAMA, it is the third most caught taxon in the Brazilian Amazon by weight, a ...

'' third and ''

Brycon ''Brycon'' is a genus of fish in the family Characidae found in freshwater habitats in Central and South America, ranging from southern Mexico to northern Argentina. Despite not being closely related to true trout, they are sometimes called ...

'' spp. fifth).Araujo-Lima, C.A.R.M.; and M.L. Ruffino (2003). Migratory Fishes of the Brazilian Amazon. Pp. 233—302 in: Carolsfeld, J.; B. Harvey; C. Ross; and A. Baer (editors). Migratory Fishes of South America. The flesh of ''Brachyplatystoma'' is considered to be of excellent quality. Human activities are a concern in that they may disrupt these fishes. Dams may impede the migration of these fish both to and from their spawning sites.

Gold prospecting Gold prospecting is the act of searching for new gold deposits. Methods used vary with the type of deposit sought and the resources of the prospector. Although traditionally a commercial activity, in some developed countries placer gold prosp ...

may also frighten these large catfishes in the areas where they spawn. Deforestation can also affect the upriver spawning habitats. Because these fish may migrate back to their original tributary, overfishing in a certain area may reduce a whole genetic group. In some areas, catches have been diminishing due to

overfishing Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in t ...

. ''B. rousseauxii'' is known to be overfished, and this same situation may apply to other ''Brachyplatystoma''. Catch rates of ''B. filamentosum'' have decreased drastically from 1977. Conversely, there have been recorded incidents where large ''B. filamentosum'' have preyed on humans. In one account documented on the television series ''

River Monsters ''River Monsters'' is a British and United States, American wildlife Documentary film, documentary Television show, television programme produced for Animal Planet by Icon Films of Bristol, United Kingdom. It is hosted by extreme Angling, ang ...

'', a local fisherman was found having been swallowed head-first up to his waist by one of these catfish, though neither the fish nor the fisherman survived the encounter.

In the aquarium

''Brachyplatystoma'' are generally uncommon in the

fishkeeping Fishkeeping is a popular hobby, practiced by aquarists, concerned with keeping fish in a home aquarium or garden pond. There is also a piscicultural fishkeeping industry, serving as a branch of agriculture. Origins of fishkeeping Fish hav ...

trade. The large size of many of these fish prohibit them from being maintained in anything but the largest of aquaria, or in public aquariums. ''B. tigrinum'' is a highly prized fish in the

hobby, and is one of the most expensive fish in this family. These fish should be kept in well-oxygenated aquarium with a high current. Due to their large size, the aquarium should also be spacious and any tankmates must be large enough not to be eaten. The aquarium should not be brightly lit, and hiding places should be available. Breeding is unreported in captivity. Due to the similarity between ''B. tigrinum'' and ''B. juruense'', the latter is often known as the False Zebra Shovelnose or False Tigrinus (as ''B. tigrinum'' was previously known as ''Merodontotus tigrinus'').

Species

There are currently seven recognized species in this genus (common name shown in second parentheses): *Subgenus ''Brachyplatystoma'': ** '' Brachyplatystoma juruense'' (

Boulenger Boulenger is a surname. Notable people with the surname include: * Benjamin Boulenger (born 1990), French footballer * Edward George Boulenger (1888–1946), British zoologist, director of aquarium at London Zoo * George Albert Boulenger (1858– ...

, 1898) (Zebra catfish, Juruense catfish, Gold Zebra Pim, False Tigrinus) ** '' Brachyplatystoma platynemum''

, 1898 (Slobbering catfish) ** '' Brachyplatystoma tigrinum'' ( Britski, 1981) (Tigerstriped catfish, Zebra shovelnose, Royal tiger shovelnose) ** ''

Brachyplatystoma vaillantii ''Brachyplatystoma vaillantii'', the Laulao catfish or piramuta, is a species of catfish Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resembl ...

'' (

Valenciennes Valenciennes (, also , , ; nl, label=also Dutch, Valencijn; pcd, Valincyinnes or ; la, Valentianae) is a commune in the Nord department, Hauts-de-France, France. It lies on the Scheldt () river. Although the city and region experienced a ...

, 1840) (Laulao catfish, Piramutaba) * Subgenus ''Malacobagrus'' ** '' Brachyplatystoma capapretum'' Lundberg & Akama, 2005 ** '' Brachyplatystoma filamentosum'' ( Lichtenstein, 1819) (Kumakuma, Piraíba, Filhote) ** ''

Brachyplatystoma rousseauxii ''Brachyplatystoma rousseauxii'', the gilded catfish or dourada, is a species of catfish of the family Pimelodidae The Pimelodidae, commonly known as the long-whiskered catfishes, are a family of catfishes ( order Siluriformes). Taxonomy The ...

'' ( Castelnau, 1855) (Gilded Catfish, Dourada (litt. ''golden'' in

. A name also used for several other unrelated species, e.g. '' Sparus aurata'')) One fossil species is known: *

† A dagger, obelisk, or obelus is a typographical mark that usually indicates a footnote if an asterisk has already been used. The symbol is also used to indicate death (of people) or extinction (of species). It is one of the modern descendan ...

'' Brachyplatystoma promagdalena'' Lundberg, 2005 – only known from fossils of

origin.

References

External links

* Richter, Enrico
Groß - größer - am größten: Raubwelse der Gattung Brachyplatystoma
{{Taxonbar, from=Q1917902 Pimelodidae Fish of South America Fauna of the Amazon Catfish genera Taxa named by Pieter Bleeker Freshwater fish genera