''Xyliphius'' is a

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 ...

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., Magda ...

es from

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

. This genus appears to be widespread in the Magdalena,

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 ...

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 ...

, and

Paraguay Paraguay, officially the Republic of Paraguay, is a landlocked country in South America. It is bordered by Argentina to the Argentina–Paraguay border, south and southwest, Brazil to the Brazil–Paraguay border, east and northeast, and Boli ...

Paraná River The Paraná River ( ; ; ) is a river in south-central South America, running through Brazil, Paraguay, and Argentina for some ."Parana River". Encyclopædia Britannica. Encyclopædia Britannica Online. Encyclopædia Britannica Inc., 2012. Web. ...

systems where they are most common in deeper waters. ''Xyliphius'' includes moderately sized aspredinids, ranging from 8.8–14.7

centimetre upright=1.35, Different lengths as in respect to the electromagnetic spectrum, measured by the metre and its derived scales. The microwave is in-between 1 meter to 1 millimeter. A centimetre (International spelling) or centimeter (American ...

s (3.5–5.8 in) SL. Species of this genus are distinguished from all other aspredinids by having highly reduced

eye An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

s, toothless

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 mammals h ...

e, a row of fleshy

papilla Papilla (Latin, 'nipple') or papillae may refer to: In animals * Papilla (fish anatomy), in the mouth of fish * Papilla (worms), small bumps on the surface of certain worms * Basilar papilla, a sensory organ of lizards, amphibians and fish * ...

e projecting anteriorly off the lower lip, flattened unculi and unculiferous

tubercle In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal. In plants A tubercle is generally a wart-like projectio ...

s flattened. These species also have the openings of the anterior nares with papillae and no dark saddles on the body.

Species

There are currently seven described species in this genus: * '' Xyliphius anachoretes'' C. A. A. de Figueiredo & Britto, 2010 * '' Xyliphius barbatus'' Alonso de Arámburu & Arámburu, 1962 * '' Xyliphius kryptos'' Taphorn & Lilyestrom, 1983 * '' Xyliphius lepturus'' Orcés-V. ( es), 1962 * '' Xyliphius lombarderoi'' F. J. J. Risso & E. N. P. de Risso, 1964 * '' Xyliphius magdalenae'' C. H. Eigenmann, 1912 * '' Xyliphius melanopterus'' Orcés-V. ( es), 1962

References

Aspredinidae Catfish genera Freshwater fish genera Catfish of South America Freshwater fish of South America Taxa named by Carl H. Eigenmann {{catfish-stub