''Platystacus '' is a genus of banjo catfish in the family

Aspredinidae The Aspredinidae are a small South American family (biology), family of catfishes (order (biology), order Siluriformes) also known as the banjo catfishes, with about 43 species. Distribution Aspredinids are found throughout the major tropical ri ...

. It is

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 ...

, being represented by the single

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

''Platystacus cotylephorus'', commonly known as the banded banjo . The genus ''Platystacus'' is the

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 ...

to a

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

containing '' Aspredo'' and '' Aspredinichthys''. ''P. cotylephorus'' originates from coastal waters and lower portions of rivers of northern South America, from Venezuela to northern Brazil. This species grows up to about SL and is distinguished from all other aspredinids by having 4+5 caudal fin rays. They are further distinguished from its close relatives by the absence of accessory maxillary barbels and the presence of well developed rows of unculiferous tubercles. ''P. cotylephorus'' is usually found in

brackish water 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 estuary ...

s on the soft bottoms of shallow, turbid water near to the mouths of rivers. reportedly it migrates into

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

, though

spawning Spawn is the Egg cell, eggs and Spermatozoa, sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of freely releasing eggs and sperm into a body of water (fresh or marine); the physical act is ...

is believed to take place in brackish water. This species has an unusual mode of reproduction in which the eggs are attached to the underside of the female who carries them around with her until they hatch.

References

External links

* Aspredinidae Catfish of Brazil Freshwater fish of Venezuela Taxa named by Marcus Elieser Bloch Fish described in 1794 Monotypic freshwater fish genera Catfish genera {{catfish-stub