''Hoplomyzon'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

banjo catfish The Aspredinidae are a small South American family of catfishes ( order Siluriformes) also known as the banjo catfishes, with about 43 species. Distribution Aspredinids are found throughout the major tropical rivers of South America (e.g., Magd ...

es that are native to

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

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 southe ...

. ''Hoplomyzon'' species are small, armoured aspredinids, growing up to 32 millimetres (1.3 in) SL in ''H. sexpapilostoma''. Members of this genus are distinguished from all other aspredinids by having each

premaxilla 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 ...

with two bony knobs superficially covered by fleshy

papilla Papilla (Latin, 'nipple') or papillae may refer to: In animals * Papilla (fish anatomy), in the mouth of fish * Basilar papilla, a sensory organ of lizards, amphibians and fish * Dental papilla, in a developing tooth * Dermal papillae, part of ...

e, the dorsal and ventral armor plates not overlapping, and 2–3 sets of paired pre- anal-fin plates. They also have the maxillary barbels adnate with the head and the

pectoral Pectoral may refer to: * The chest region and anything relating to it. * Pectoral cross, a cross worn on the chest * a decorative, usually jeweled version of a gorget * Pectoral (Ancient Egypt), a type of jewelry worn in ancient Egypt * Pectoralis ...

spine less than one-quarter of the fish's standard length.

Species

There are currently four described species in this genus: * '' Hoplomyzon atrizona'' G. S. Myers, 1942 * '' Hoplomyzon cardosoi'' Carvalho, Reis & Friel, 2017 * '' Hoplomyzon papillatus'' D. J. Stewart, 1985 * '' Hoplomyzon sexpapilostoma'' Taphorn & Marrero, 1990 There are also at least two

undescribed species In taxonomy, an undescribed taxon is a taxon (for example, a species) that has been discovered, but not yet formally described and named. The various Nomenclature Codes specify the requirements for a new taxon to be validly described and named. U ...

, including a blind and unpigmented species.

References

External links

* Aspredinidae Fish of South America Fish of the Amazon basin Fish of Ecuador Fish of Venezuela Catfish genera Taxa named by George S. Myers {{catfish-stub