''Pygidianops'' is a genus of pencil catfishes native to South America.

Species

There are currently four recognized species in this genus: * '' Pygidianops amphioxus'' de Pinna & Kirovsky, 2011 * '' Pygidianops cuao'' Schaefer,

Provenzano Provenzano is an Italian surname. It may refer to: *Anthony Provenzano (1917–1988), New York mobster * Bernardo Provenzano (1933–2016), member of the Sicilian Mafia *Carmen Provenzano (1942–2005), Canadian politician * Chris Provenzano, Ameri ...

, de Pinna & Baskin, 2005 * ''

Pygidianops eigenmanni ''Pygidianops'' is a genus of pencil catfishes native to South America. Species There are currently four recognized species in this genus: * ''Pygidianops amphioxus'' Mário Cesar Cardoso de Pinna, de Pinna & Alexandre Lantelme Kirovsky, Kirovsk ...

Myers Myers as a surname has several possible origins, e.g. Old French ("physician"), Old English ("mayor"), and Old Norse ("marsh"). People *Abram F. Myers (born 1889), chair of the Federal Trade Commission and later general counsel and board chai ...

, 1944 * '' Pygidianops magoi'' Schaefer,

, de Pinna & Baskin, 2005

Distribution

''P. eigenmanni'' is from the Rio Negro basin in Brazil. ''P. cuao'' is known only from

Cuao River Cuao River is a river of Venezuela. It is part of the Orinoco River basin. See also *List of rivers of Venezuela This is a list of rivers in Venezuela. By drainage basin This list is arranged by drainage basin, with respective tributaries inden ...

drainage basin. ''P. magoi'' is known only from lower

Orinoco The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers , with 76.3 percent of it in Venezuela and the remainder in Colombia. It is the fourth largest river in the wor ...

mainstem between Ciudad Bolívar and Barrancas in Venezuela.

Description

Species of ''Pygidianops'' share the extreme reduction of pigmentation, loss of the dorsal fin, the loss or extreme reduction of pectoral fins, a reduced

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

, and the reduction or complete loss of eyes in some species. These fish are markedly miniaturized, yet retain a relatively well-ossified skeleton comparable in both bone differentiation and degree of calcification to that observed in larger trichomycterids. ''P. cuao'' is distinguished from congeners by the presence of diminutive eyes (vs. eyes absent in both other species), posterior naris absent (vs. nares bilaterally paired), and the presence of a triangular skin flap at mouth corner (vs. skin flap absent). ''P. magoi'' is distinguished from all congeners by the absence of pectoral and anal fins (vs. fins present), posterior naris absent (vs. present, nares bilaterally paired), four laterosensory pores on the head (vs. six), and by the presence of 9–10 caudal fin rays (vs. 12–13). With all of its fins lost except the caudal fin, ''P. magoi'' represents the most extreme fin loss among ostariophysans. ''P. eigenmanni'' lacks eyes but has its anal and pectoral fins.

References

{{Taxonbar, from=Q7262999 Trichomycteridae Fish of South America Fish of Brazil Fish of Venezuela Freshwater fish genera Catfish genera Taxa named by George S. Myers