Pseudoplatystoma
Encyclopedia
Pseudoplatystoma is a genus
of several South America
n catfish
species of family
Pimelodidae
. The three species are known by a number of different common name
s. They inhabit the major rivers of north-eastern Argentina
, Paraguay
, Peru
, Bolivia
, Uruguay
and Brazil
. They prefer the main channels and tend to stay at maximum depth. They have robust bodies, and are important food fish.
assemblage of catfishes.
P. fasciatum was the first species to be described, under the name Siluris fasciatus, by Carolus Linnaeus
. In 1829, P. corruscans was described under the name Platystoma corruscans, and over a decade later P. tigrinum was described as Platystoma tigrinum. It was not until 1862 that Pseudoplatystoma was described and these species transferred to it, with P. fasciatum as type species
.
Unrecognized species of Pseudoplatystoma have been included under the names P. fasciatum and P. tigrinum for decades. This genus traditionally contained only three species until 2007; there are currently eight species in this genus. P. punctifer, P. orinocoense, P. magdaleniatum, and P. reticulatum were formerly recognized as P. fasciatum, but are now recognized as distinct species. P. metaense is also now recognized as a distinct species from P. tigrinum.
Two clade
s are recognized within the genus. One is the P. fasciatum clade which includes P. fasciatum, P. punctifer, P. orinocoense, P. magdaleniatum, P. reticulatum, and P. corruscans. Within this clade, P. fasciatum and P. punctifer are sister species
, and P. orinocoense is sister to the clade formed by these two species. The other, the P. tigrinum clade, includes only P. tigrinum and P. metaense. They are differentiated by anatomical characters.
The intergeneric relationships of this genus are well established. This genus forms a monophyletic
group with Sorubim
, Sorubimichthys, Hemisorubim, and Zungaro. Of these genera, Hemisorubim is most closely related to Pseudoplatystoma.
, Orinoco, Paraná
, São Francisco
, Magdalena
, Rupununi, Essequibo
, and Suriname River
. They have not been reported from the Pacific basin. P. fasciatum inhabits the Guyana region, including the Essequibo and Suriname rivers and their tributaries, in the countries of Guyana
, Suriname
, and French Guiana
. P. tigrinum is found in the Amazon River in Brazil
, Colombia
, Ecuador
, Peru
, and Venezuela
. P. corruscans originates from the Paraná River and São Francisco River in the countries of Argentina
, Brazil, Paraguay
, and Uruguay
. P. orinocoense is named for and endemic to the Orinoco River of Venezuela. P. punctifer lives in the Amazon River in Bolivia
, Brazil, Colombia, Ecuador, Peru, and Venezuela. P. metaense is distributed in the Orinoco River in Colombia and Venezuela; it is named for the Meta River
, the type locality
, a tributary of the Orinoco River. P. magdaleniatum is named for and endemic to the Magdalena River drainage, including the Cauca River
of Colombia. P. reticulatum inhabits the central Amazon and Paraná River in Argentina, Bolivia, Brazil, Paraguay, and Uruguay.
Pseudoplatystoma species live in a diverse range of habitats such as great rivers, lakes, side channels, floating meadows, and flooded forests. P. fasciatum is found in river beds and sometimes in flooded forests. Though it is biologically similar to P. tigrinum, this fish seems to favor shadier streams. P. tigrinum occurs in estuarine
zones, mainly upstream of the first rapids up to the basin's headwaters. They live in the main bed of slow or fast zones, and the juveniles particularly live in flooded forests.
process
extending backward to contact the predorsal
plate, and a very long fontanel.
After gonad
al maturation, females tend to grow faster than males. They have a large, depressed head with an expandable mouth. The eyes and teeth are small. They have dorsal and pectoral fin spines; in P. fasciatum, there is also an additional, smaller, dorsal spinelet preceding the dorsal spine. They exhibit typical barbel
s of catfish, the maxillary barbels sometimes being quite long, especially in juveniles.
P. fasciatum has 10–11 dark vertical bars that are relatively wider than other species of the Amazon, and there are fewer white vertical bars than dark ones; the pectoral fins and pelvic fins are darker with few or no spots; and the skull is at least 1/6 narrower than other species. It reaches a maximum of 90 centimetre
s (35 in
) TL
.
P. tigrinum is distinguished by the presence of loop–like bands connecting to, or extending to, dorsal region and continuing onto other side of body; loop–like bars form cells. The adipose fin also has some loop-like bands and spots, but there are no discrete dark spots on the sides of the body. It reaches a maximum size of 130 cm (51 in) TL.
P. corruscans has a body covered by large spots in six to eight eight rows with 4–13 pale vertical bars. The adipose fin contains 5–10 or no spots, the caudal fin has few spots. It reaches a maximum size of 114 cm (45 in) TL.
P. orinocoense has straight, vertical bars on its body longer than those of P. faciatum and P. punctifer that extend to or connect dorsally. The bars of the anterior region extend below the dusky dorsolateral area. There are usually no spots below the lateral line
, though some individuals may have two or three. It has a maximum recorded length of 49 cm (19 in) TL.
P. punctifer has straight, dark, vertical bars with pale short lines; these bars do not connect across the dorsum on the opposite side. There are free discrete spots on below the laterla line. The adipose fin has fewer spots (6–8) than P. fasciatum (10–11). It reaches a maximum length of 140 cm (55 in) TL.
P. metaense has dark spots randomly distributed over the dusky region of its body; also, there are no more than five straight dark vertical bars on the side of the body. The adipose fin has fewer spots (5–7) than in P. tigrinum (8–10). The pectoral and pelvic fins are pale without any dusky pigmentation. It has a maximum recorded length of about 53 cm (21 in) TL.
P. magdaleniatum has wide, straight, dark vertical bars on its sides. There are no loops on the nape
and associated areas. The pectoral fin has no spots, the dorsal fin has few or no spots, and the adipose has 6–7 large spots. It has a maximum recorded length of 100 cm (39 in).
P. reticulatum is named for its pattern; it has loop-like dark bars forming a reticulating pattern, never straight as in P. fasciatum, P. orinocoense, and P. punctifer. It has dark, loop–like bars join those in the dorsal region of the body forming distinct cells. It also has longer loop–like dark bars, extending far below the lateral line. The head shows either spots or loops. The anal fin is always with spots. The lower jaw is pointed. It has a maximum recorded length of about 60 cm (24 in) TL.
Juvenile Pseudoplatystoma are quite different in appearance from adults. These fishes' juvenile coloration differs from their adult coloration, and the patterning is different. In the juvenile, the fish is dark on its back with an obvious boundary between the white of its sides and belly; also, the fish lacks stripes of P. fasciatum and P. tigrinum, but has spots instead. The adult colour is brown-olive, with about 13 or 14 dark transverse bands reaching up to the belly, which is white with a few dark spots.
fish. P. orinocense and P. tigrinum make short migrations. At the end of the dry season, P. tigrinum can migrate at the same time as its prey, and then return at the end of the rainy season.
The migration of P. corruscans is heavily tied to flooding. As the rainfall occurs, there is the greates reproductive activity, highest rate of development of gonad
s, and the most amount of energy spent in migration.
es, cichlid
s, loricariids
, and characins. They may consume on other fish such as sábalo
s, Prochilodus lineatus, and boga
s, Leporinus obtusidens. Opportunistic feeders, they may also feed on crustacean
s such as crab
s or shrimp
s.
and Marmoré
rivers. These fish are being overexploited
in their range, and it is possible that uncontrolled fishing has led to the disappearance of Pseudoplatystoma species in some local tributaries of the Amazon, Orinoco, and Magdalena. In the Argentine province of Entre Ríos
alone, about 27,000 tonne
s of Pseudoplatystoma sp. are obtained every year, comprising 70 to 80% of the total capture there, mostly concentrated on the fishing area near the city of Victoria
, opposite Rosario
, Santa Fe
.
The capture of P. corruscans has declined greatly due to changes in their environment. This fish has a high commercial value due to the excellent quality of its meat, its high marketability, and its marked participation in commercial fishing. Spawning of this fish can be induced with hormone
s and there is high potential for commercial production.
P. fasciatum and P. tigrinum are often found in public aquariums.
and South America; however, they are usually at a size too small for certain identification, but more than one species may be imported. These species appear in the aquarium
hobby, where they are most often sold under the name "tiger shovelnose" or "tiger shovelnose catfish". These fish prove to be hardy. However, the large adult size is problematic for both matters of housing as well as finding suitable tankmates that will not be consumed. With the appetite these fish have, finding enough good food may present some difficulty.
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 several South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
n 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...
species of 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...
Pimelodidae
Pimelodidae
Pimelodidae, commonly known as the long-whiskered catfishes, is a family of catfishes .-Taxonomy:Pimelodidae has undergone much revision. Currently, the family contains about 30 genera and about 90 recognized and known but unnamed species...
. The three species are known by a number of different common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
s. They inhabit the major rivers of north-eastern Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
, Paraguay
Paraguay
Paraguay , officially the Republic of Paraguay , is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to the east and northeast, and Bolivia to the northwest. Paraguay lies on both banks of the Paraguay River, which runs through the center of the...
, Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
, Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
, Uruguay
Uruguay
Uruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...
and Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
. They prefer the main channels and tend to stay at maximum depth. They have robust bodies, and are important food fish.
Common names
In their native waters, these fish may be called Surubí in guaraní. This name is also used in some Spanish speaker countries. In Peruvian Spanish is called Doncella or Zúngaro. P. corruscans may be called moleque or pintado. They often are referred to in the vernacular as Bagre rayado or Pintadillo (tiger catfish or tiger–shovelnose). P. corruscans, P. fasciatum, and P. tigrinum are also known as Spotted Sorubim, Barred Sorubim, and Tiger Sorubim, respectively. This genus contains the fish commonly known as the tiger shovelnose catfish in the aquarium hobby, though the species in this genus are relatively easy to confuse.Taxonomy
Pseudoplatystoma is a monophyleticMonophyly
In common cladistic usage, a monophyletic group is a taxon which forms a clade, meaning that it contains all the descendants of the possibly hypothetical closest common ancestor of the members of the group. The term is synonymous with the uncommon term holophyly...
assemblage of catfishes.
P. fasciatum was the first species to be described, under the name Siluris fasciatus, by Carolus Linnaeus
Carolus Linnaeus
Carl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
. In 1829, P. corruscans was described under the name Platystoma corruscans, and over a decade later P. tigrinum was described as Platystoma tigrinum. It was not until 1862 that Pseudoplatystoma was described and these species transferred to it, with P. fasciatum as type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
.
Unrecognized species of Pseudoplatystoma have been included under the names P. fasciatum and P. tigrinum for decades. This genus traditionally contained only three species until 2007; there are currently eight species in this genus. P. punctifer, P. orinocoense, P. magdaleniatum, and P. reticulatum were formerly recognized as P. fasciatum, but are now recognized as distinct species. P. metaense is also now recognized as a distinct species from P. tigrinum.
Two clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
s are recognized within the genus. One is the P. fasciatum clade which includes P. fasciatum, P. punctifer, P. orinocoense, P. magdaleniatum, P. reticulatum, and P. corruscans. Within this clade, P. fasciatum and P. punctifer are sister species
Cladistics
Cladistics is a method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants . For example, birds, dinosaurs, crocodiles, and all descendants of their most recent common ancestor form a clade...
, and P. orinocoense is sister to the clade formed by these two species. The other, the P. tigrinum clade, includes only P. tigrinum and P. metaense. They are differentiated by anatomical characters.
The intergeneric relationships of this genus are well established. This genus forms a monophyletic
Monophyly
In common cladistic usage, a monophyletic group is a taxon which forms a clade, meaning that it contains all the descendants of the possibly hypothetical closest common ancestor of the members of the group. The term is synonymous with the uncommon term holophyly...
group with Sorubim
Sorubim
Sorubim is a small genus of Pimelodid catfish originating from tropical South America. A number of characteristics allows the differentiation of each species in the genus...
, Sorubimichthys, Hemisorubim, and Zungaro. Of these genera, Hemisorubim is most closely related to Pseudoplatystoma.
Distribution and habitat
The distribution of Pseudoplatystoma species includes the great river basins of South America: the AmazonAmazon 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...
, Orinoco, Paraná
Paraná 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...
, 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...
, Magdalena
Magdalena River
The Magdalena River is the principal 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 its lower reaches, in spite of the shifting sand bars at the mouth of its delta, as...
, Rupununi, Essequibo
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...
, and Suriname River
Suriname River
The Suriname River is 480 km long and flows through the country Suriname. Its sources are located in the Guiana Highlands on the border between the Wilhelmina Mountains and the Eilerts de Haan Mountains...
. They have not been reported from the Pacific basin. P. fasciatum inhabits the Guyana region, including the Essequibo and Suriname rivers and their tributaries, in the countries of Guyana
Guyana
Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...
, Suriname
Suriname
Suriname , officially the Republic of Suriname , is a country in northern South America. It borders French Guiana to the east, Guyana to the west, Brazil to the south, and on the north by the Atlantic Ocean. Suriname was a former colony of the British and of the Dutch, and was previously known as...
, and French Guiana
French Guiana
French Guiana is an overseas region of France, consisting of a single overseas department located on the northern Atlantic coast of South America. It has borders with two nations, Brazil to the east and south, and Suriname to the west...
. P. tigrinum is found in the Amazon River in Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
, Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
, Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
, and Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
. P. corruscans originates from the Paraná River and São Francisco River in the countries of Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
, Brazil, Paraguay
Paraguay
Paraguay , officially the Republic of Paraguay , is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to the east and northeast, and Bolivia to the northwest. Paraguay lies on both banks of the Paraguay River, which runs through the center of the...
, and Uruguay
Uruguay
Uruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...
. P. orinocoense is named for and endemic to the Orinoco River of Venezuela. P. punctifer lives in the Amazon River in Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
, Brazil, Colombia, Ecuador, Peru, and Venezuela. P. metaense is distributed in the Orinoco River in Colombia and Venezuela; it is named for the Meta River
Meta River
The Meta River is formed in the Meta Department, Colombia by the confluence of the Humea, Guatiquía and Guayuriba rivers. It flows east-northeastward across the Llanos Orientales plains of Colombia through an ancient fault...
, the type locality
Biological type
In biology, a type is one particular specimen of an organism to which the scientific name of that organism is formally attached...
, a tributary of the Orinoco River. P. magdaleniatum is named for and endemic to the Magdalena River drainage, including the Cauca River
Cauca River
The Cauca River is a river in Colombia that lies between the Occidental and Central cordilleras. Born in southwestern Colombia near the city of Popayán, it joins the Magdalena River near Pinillos in Bolívar Department, and the combined river eventually flows out into the Caribbean Sea. It has a...
of Colombia. P. reticulatum inhabits the central Amazon and Paraná River in Argentina, Bolivia, Brazil, Paraguay, and Uruguay.
Pseudoplatystoma species live in a diverse range of habitats such as great rivers, lakes, side channels, floating meadows, and flooded forests. P. fasciatum is found in river beds and sometimes in flooded forests. Though it is biologically similar to P. tigrinum, this fish seems to favor shadier streams. P. tigrinum occurs in estuarine
Estuary
An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....
zones, mainly upstream of the first rapids up to the basin's headwaters. They live in the main bed of slow or fast zones, and the juveniles particularly live in flooded forests.
Physical characteristics
Pseudoplatystoma species are all large, boldly striped or spotted catfishes. They are familiar due to their distinctively marked color patterns. They are also recognized due to a depressed head, an occipitalOcciput
The occiput is the anatomical term for the posterior portion of the head, in insects the posterior part of those head capsule.-Clinical significance:Trauma to the occiput can cause a basilar skull fracture....
process
Process (anatomy)
In anatomy, a process is a projection or outgrowth of tissue from a larger body. The vertebra has several kinds of processes,such as: transverse process, prezygapophysis, postzygapophysis.-Examples:Examples of processes include:...
extending backward to contact the predorsal
Dorsum (biology)
In anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...
plate, and a very long fontanel.
After gonad
Gonad
The gonad is the organ that makes gametes. The gonads in males are the testes and the gonads in females are the ovaries. The product, gametes, are haploid germ cells. For example, spermatozoon and egg cells are gametes...
al maturation, females tend to grow faster than males. They have a large, depressed head with an expandable mouth. The eyes and teeth are small. They have dorsal and pectoral fin spines; in P. fasciatum, there is also an additional, smaller, dorsal spinelet preceding the dorsal spine. They exhibit typical barbel
Barbel (anatomy)
A barbel on a fish is a slender, whiskerlike tactile organ near the mouth. Fish that have barbels include the catfish, the carp, the goatfish, sturgeon, the zebrafish and some species of shark...
s of catfish, the maxillary barbels sometimes being quite long, especially in juveniles.
P. fasciatum has 10–11 dark vertical bars that are relatively wider than other species of the Amazon, and there are fewer white vertical bars than dark ones; the pectoral fins and pelvic fins are darker with few or no spots; and the skull is at least 1/6 narrower than other species. It reaches a maximum of 90 centimetre
Centimetre
A centimetre is a unit of length in the metric system, equal to one hundredth of a metre, which is the SI base unit of length. Centi is the SI prefix for a factor of . Hence a centimetre can be written as or — meaning or respectively...
s (35 in
Inch
An inch is the name of a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot...
) TL
Fish measurement
Fish measurement refers to the measuring of the length of individual fish and of various parts of their anatomy. These data are used in many areas of ichthyology, including taxonomy and fisheries biology.-Overall length:...
.
P. tigrinum is distinguished by the presence of loop–like bands connecting to, or extending to, dorsal region and continuing onto other side of body; loop–like bars form cells. The adipose fin also has some loop-like bands and spots, but there are no discrete dark spots on the sides of the body. It reaches a maximum size of 130 cm (51 in) TL.
P. corruscans has a body covered by large spots in six to eight eight rows with 4–13 pale vertical bars. The adipose fin contains 5–10 or no spots, the caudal fin has few spots. It reaches a maximum size of 114 cm (45 in) TL.
P. orinocoense has straight, vertical bars on its body longer than those of P. faciatum and P. punctifer that extend to or connect dorsally. The bars of the anterior region extend below the dusky dorsolateral area. There are usually no spots below the lateral line
Lateral line
The lateral line is a sense organ in aquatic organisms , used to detect movement and vibration in the surrounding water. Lateral lines are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail...
, though some individuals may have two or three. It has a maximum recorded length of 49 cm (19 in) TL.
P. punctifer has straight, dark, vertical bars with pale short lines; these bars do not connect across the dorsum on the opposite side. There are free discrete spots on below the laterla line. The adipose fin has fewer spots (6–8) than P. fasciatum (10–11). It reaches a maximum length of 140 cm (55 in) TL.
P. metaense has dark spots randomly distributed over the dusky region of its body; also, there are no more than five straight dark vertical bars on the side of the body. The adipose fin has fewer spots (5–7) than in P. tigrinum (8–10). The pectoral and pelvic fins are pale without any dusky pigmentation. It has a maximum recorded length of about 53 cm (21 in) TL.
P. magdaleniatum has wide, straight, dark vertical bars on its sides. There are no loops on the nape
Nape
The nape is the back of the neck. In technical anatomical/medical terminology, the nape is referred to by the word nucha, which also gives the adjective corresponding to "nape" in English, "nuchal"....
and associated areas. The pectoral fin has no spots, the dorsal fin has few or no spots, and the adipose has 6–7 large spots. It has a maximum recorded length of 100 cm (39 in).
P. reticulatum is named for its pattern; it has loop-like dark bars forming a reticulating pattern, never straight as in P. fasciatum, P. orinocoense, and P. punctifer. It has dark, loop–like bars join those in the dorsal region of the body forming distinct cells. It also has longer loop–like dark bars, extending far below the lateral line. The head shows either spots or loops. The anal fin is always with spots. The lower jaw is pointed. It has a maximum recorded length of about 60 cm (24 in) TL.
Juvenile Pseudoplatystoma are quite different in appearance from adults. These fishes' juvenile coloration differs from their adult coloration, and the patterning is different. In the juvenile, the fish is dark on its back with an obvious boundary between the white of its sides and belly; also, the fish lacks stripes of P. fasciatum and P. tigrinum, but has spots instead. The adult colour is brown-olive, with about 13 or 14 dark transverse bands reaching up to the belly, which is white with a few dark spots.
Reproduction
Pseudoplatystoma are all migratoryFish migration
Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres...
fish. P. orinocense and P. tigrinum make short migrations. At the end of the dry season, P. tigrinum can migrate at the same time as its prey, and then return at the end of the rainy season.
The migration of P. corruscans is heavily tied to flooding. As the rainfall occurs, there is the greates reproductive activity, highest rate of development of gonad
Gonad
The gonad is the organ that makes gametes. The gonads in males are the testes and the gonads in females are the ovaries. The product, gametes, are haploid germ cells. For example, spermatozoon and egg cells are gametes...
s, and the most amount of energy spent in migration.
Diet
These fish are nocturnal hunters. They are primarily piscivorous, feeding on fish such as electric knifefishGymnotiformes
The Gymnotiformes are a group of teleost bony fishes commonly known as the Neotropical or South American knifefishes. They have long bodies and swim using undulations of their elongated anal fin...
es, cichlid
Cichlid
Cichlids are fishes from the family Cichlidae in the order Perciformes. Cichlids are members of a group known as the Labroidei along with the wrasses , damselfish , and surfperches . This family is both large and diverse. At least 1,300 species have been scientifically described, making it one of...
s, loricariids
Loricariidae
Loricariidae is the largest family of catfish , with almost 700 species and new species being described each year. Loricariids originate from fresh water habitats of Costa Rica, Panama, and tropical and subtropical South America. These fish are noted for the bony plates covering their bodies and...
, and characins. They may consume on other fish such as sábalo
Prochilodus lineatus
Prochilodus lineatus is a South American species of ray-finned fish that inhabits the basin of the Paraná River and the Paraguay River in the Argentine Mesopotamia and Paraguay, the Pilcomayo River in Bolivia, and the Paraíba do Sul River in Brazil...
s, Prochilodus lineatus, and boga
Leporinus obtusidens
Leporinus obtusidens is a South American species of ray-finned fish that inhabits the basins of the Paraná River and the Río de la Plata, the Uruguay River, and the São Francisco River...
s, Leporinus obtusidens. Opportunistic feeders, they may also feed on 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 such as crab
Crab
True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
s or 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...
s.
Relationship to humans
Pseudoplatystoma are of considerable economic value; all are sold in open fish markets throughout South America. They are important food fish for human consumption. P. fasciatum has a succulent yellowish flesh that is without bones. P. tigrinum is the most important catfish in gill-net fisheries of GuaporéGuaporé
Guaporé may refer to:*Guaporé River in Brazil/Bolivia*Guaporé, Rio Grande do Sul in Brazil*The former name of Rondônia...
and Marmoré
Mamoré Province
Mamoré is a province in the Beni Department, Bolivia.-References:...
rivers. These fish are being overexploited
Overfishing
Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....
in their range, and it is possible that uncontrolled fishing has led to the disappearance of Pseudoplatystoma species in some local tributaries of the Amazon, Orinoco, and Magdalena. In the Argentine province of Entre Ríos
Entre Ríos Province
Entre Ríos is a northeastern province of Argentina, located in the Mesopotamia region. It borders the provinces of Buenos Aires , Corrientes and Santa Fe , and Uruguay in the east....
alone, about 27,000 tonne
Tonne
The tonne, known as the metric ton in the US , often put pleonastically as "metric tonne" to avoid confusion with ton, is a metric system unit of mass equal to 1000 kilograms. The tonne is not an International System of Units unit, but is accepted for use with the SI...
s of Pseudoplatystoma sp. are obtained every year, comprising 70 to 80% of the total capture there, mostly concentrated on the fishing area near the city of Victoria
Victoria, Entre Ríos
Victoria is a city in the southwest of the province of Entre Ríos, Argentina. It is located on the eastern shore of the Paraná River, opposite Rosario, Santa Fe, to which it is connected since 2003 by the Rosario-Victoria Bridge .The site of a 1750 defeat of a native uprising and an 1810 oratory to...
, opposite Rosario
Rosario
Rosario is the largest city in the province of Santa Fe, Argentina. It is located northwest of Buenos Aires, on the western shore of the Paraná River and has 1,159,004 residents as of the ....
, Santa Fe
Santa Fe Province
The Invincible Province of Santa Fe, in Spanish Provincia Invencible de Santa Fe , is a province of Argentina, located in the center-east of the country. Neighboring provinces are from the north clockwise Chaco , Corrientes, Entre Ríos, Buenos Aires, Córdoba, and Santiago del Estero...
.
The capture of P. corruscans has declined greatly due to changes in their environment. This fish has a high commercial value due to the excellent quality of its meat, its high marketability, and its marked participation in commercial fishing. Spawning of this fish can be induced with hormone
Hormone
A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...
s and there is high potential for commercial production.
P. fasciatum and P. tigrinum are often found in public aquariums.
In the aquarium
Juvenile Pseudoplatystoma are marked as ornamental fish in both NorthNorth America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
and South America; however, they are usually at a size too small for certain identification, but more than one species may be imported. These species appear in the 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...
hobby, where they are most often sold under the name "tiger shovelnose" or "tiger shovelnose catfish". These fish prove to be hardy. However, the large adult size is problematic for both matters of housing as well as finding suitable tankmates that will not be consumed. With the appetite these fish have, finding enough good food may present some difficulty.