''Batrochoglanis'' is a small

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

catfish Catfish (or catfishes; order (biology), order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Catfish are common name, named for their prominent barbel (anatomy), barbels, which resemble a cat's whiskers, though not ...

es (

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Siluriformes) of the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Pseudopimelodidae The Pseudopimelodidae are a small family (about 40 species) of catfishes known as the bumblebee catfishes or dwarf marbled catfishes. Some of these fish are popular aquarium fish. Taxonomy This family was formerly a subfamily of Pimelodidae. Pse ...

Species

There are currently five recognized species in this genus: * '' Batrochoglanis acanthochiroides'' (Güntert, 1942) * '' Batrochoglanis melanurus'' Shibatta & Pavanelli, 2005 * '' Batrochoglanis raninus'' (

Valenciennes Valenciennes (, also , , ; ; or ; ) is a communes of France, commune in the Nord (French department), Nord Departments of France, department, Hauts-de-France, France. It lies on the Scheldt () river. Although the city and region experienced ...

, 1840) * '' Batrochoglanis transmontanus'' ( Regan, 1913) * '' Batrochoglanis villosus'' (

Eigenmann Eigenmann () is a surname. Notable persons with that surname include: * Andi Eigenmann (born 1990), Filipino actress * Carl H. Eigenmann (1863–1927), German–American ichthyologist, husband of Rosa Eigenmann * Eduardo de Mesa Eigenmann, birth n ...

, 1912)

Distribution

''Batrochoglanis'' species are known and distributed throughout 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 ...

basin, rivers of the

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

ian and

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

n Pacific coast, the northern region of South America, and the

Paraguay River The Paraguay River (''Ysyry Paraguái'' in Guarani language, Guarani, ''Rio Paraguai'' in Portuguese language, Portuguese, ''Río Paraguay'' in Spanish language, Spanish) is a major river in south-central South America, running through Brazil, Bol ...

basin. ''B. acanthochiroides'' is distributed in the

Catatumbo River The Catatumbo River () is a river rising in northern Colombia, flowing into Lake Maracaibo in Venezuela. The Catatumbo River is approximately long. It forms a part of the international boundary between the two countries. The river flows through ...

basin of the

Maracaibo Maracaibo ( , ; ) is a city and municipality in northwestern Venezuela, on the western shore of the strait that connects Lake Maracaibo to the Gulf of Venezuela. It is the largest city in Venezuela and is List of cities in Venezuela by population ...

basin. ''B. melanurus'' is only known from its type locality in the

basin of Brazil. ''B. raninus'' is found in the Amazon River basin,

Guyana Guyana, officially the Co-operative Republic of Guyana, is a country on the northern coast of South America, part of the historic British West Indies. entry "Guyana" Georgetown, Guyana, Georgetown is the capital of Guyana and is also the co ...

, and

French Guiana French Guiana, or Guyane in French, is an Overseas departments and regions of France, overseas department and region of France located on the northern coast of South America in the Guianas and the West Indies. Bordered by Suriname to the west ...

. ''B. transmontanus'' originates from Baudó,

San Juan San Juan, Spanish for Saint John (disambiguation), Saint John, most commonly refers to: * San Juan, Puerto Rico * San Juan, Argentina * San Juan, Metro Manila, a highly urbanized city in the Philippines San Juan may also refer to: Places Arge ...

, Patía and

Durango Durango, officially the Free and Sovereign State of Durango, is one of the 31 states which make up the Political divisions of Mexico, 32 Federal Entities of Mexico, situated in the northwest portion of the country. With a population of 1,832,650 ...

river basins. ''B. villosus'' is found in the

Demerara River The Demerara River is a river in eastern Guyana that rises in the central rainforests of the country and flows to the north for 346 kilometres until it reaches the Atlantic Ocean. Georgetown, Guyana's largest seaport and capital, is situated on ...

of the Essequibo basin,

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 Amazon River basins.

Description

Species of this genus have rounded, wider than deep bodies; large heads, rounded in dorsal view;

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins (the other being the laterally positioned pectoral fins). The pelvic fins are homologous to the hi ...

s originating at vertical line through the end of the

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

; short

caudal peduncle Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

s, with

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

procurrent rays close to

adipose Adipose tissue (also known as body fat or simply fat) is a loose connective tissue composed mostly of adipocytes. It also contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, Blood vessel, vascular endothel ...

and

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

s; emarginated caudal fins, with rounded lobes, or completely rounded; incomplete lateral lines, sometimes surpassing the adipose-fin end, but never reaching the caudal fin. Three color patterns of the caudal fin in ''Batrochoglanis'' species are known. The first pattern, in ''B. raninus'', ''B. transmontanus'' and ''B. acanthochiroides'', is a light caudal fin, with a dark band on the posterior third. The second pattern, in ''B. villosus'', is a light caudal fin, with dark dots irregularly distributed. The third pattern, found in ''B. melanurus'', has the caudal fin completely dark. The coloration pattern is useful for separating species, but apparently does not allow inferences about

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

relationships to be safely made, since this character is widespread in this family. ''B. acanthochiroides'', the largest species, grows to 80.0 centimetres (31 in) TL. ''B. melanurus'' has a maximum length of 13.7 cm (5.39 in) SL. ''B. raninus'' reaches a length of 20.0 (7.87 in) SL. ''B. transmontanus'' grows to a length of 25.0 cm (9.84 in) TL. ''B. villosus'' reaches a length of 14.8 cm (5.83 in) TL.

Ecology

''B. transmontanus'' is recorded to live in rivers. ''B. raninus'' commonly occurs in creeks as well as in rivers. It is found in very shady, deep zones of rivers where the current is slow, the bottom is shady, and the gravel is covered with plant debris. During the day, ''B. raninus'' lies hidden under branches or rocks. It hunts by stalking, swallowing prey within its range. When young, ''B. raninus'' feeds on micro-

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s and aquatic

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e, then shifts its diet to fishes of notable size.

References

{{Taxonbar, from=Q4869611 Pseudopimelodidae Fish of South America Fish of the Amazon basin Catfish genera Taxa named by Theodore Gill Freshwater fish genera