''Aphanotorulus emarginatus'' is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the

Amazon River The Amazon River (, ; es, Río Amazonas, pt, Rio Amazonas) in South America is the largest river by discharge volume of water in the world, and the disputed longest river system in the world in comparison to the Nile. The headwaters of t ...

basin. The species reaches 15 cm (5.9 inches) in total length. It is known to be a facultative air-breather. ''A. emarginatus'' was originally described as '' Hypostomus emarginatus'' by

Achille Valenciennes Achille Valenciennes (9 August 1794 – 13 April 1865) was a French zoologist. Valenciennes was born in Paris, and studied under Georges Cuvier. His study of parasitic worms in humans made an important contribution to the study of parasitology. ...

in 1840, although it was transferred to the genus '' Squaliforma'' (now considered invalid) after the genus' designation by I. J. H. Isbrücker, I. Seidel, J. Michels, E. Schraml, and A. Werner in 2001. In 2004, Jonathan W. Armbruster classified the species within ''Hypostomus'' instead of ''Squaliforma''. In 2016, following a review of '' Isorineloricaria'' and ''

Aphanotorulus ''Aphanotorulus'' is a genus of armored catfishes native to the Amazon, Orinoco, Essequibo and Jaguaribe basins in South America.Ray, C.K. & Armbruster, J.W. (2016): The genera ''Isorineloricaria'' and ''Aphanotorulus'' (Siluriformes: Loricar ...

'' by C. Keith Ray and Armbruster (both of

Auburn University Auburn University (AU or Auburn) is a public land-grant research university in Auburn, Alabama. With more than 24,600 undergraduate students and a total enrollment of more than 30,000 with 1,330 faculty members, Auburn is the second largest uni ...

), the species was reclassified as a member of ''Aphanotorulus'', although

FishBase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

still lists the species as ''Squaliforma emarginata''. A. emarginatus appears in the aquarium trade, where it is typically referred to either as the red-fin thresher pleco or by one of five associated L-numbers, which are L-011, L-035, L-108, and L-116.

References

Loricariidae Fish of the Amazon basin Fish described in 1840 {{Loricariidae-stub