''Guyanancistrus longispinis'' is a species of catfish in the family Loricariidae that is of disputed classification. It is native to South America, where it occurs in the Oyapock basin in French Guiana. It is typically seen in shallow

rapids Rapids are sections of a river where the river bed has a relatively steep gradient, causing an increase in water velocity and turbulence. Rapids are hydrological features between a ''run'' (a smoothly flowing part of a stream) and a ''cascade''. ...

with rocky substrates and moderate levels of illumination. It is known to occur alongside the species '' Guyanancistrus brevispinis'', '' Harttia fowleri'', and ''

Crenicichla ternetzi ''Crenicichla ternetzi'' is a species of cichlid Cichlids are fish from the family Cichlidae in the order Cichliformes. Cichlids were traditionally classed in a suborder, the Labroidei, along with the wrasses ( Labridae), in the order Percif ...

'', as well as members of the genus '' Ancistrus''. The species reaches 10.4 cm (4.1 inches) in

standard length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish m ...

and may be a facultative air-breather. ''Guyanancistrus longispinis'' was initially described as a species of ''

Lasiancistrus ''Lasiancistrus'' is a genus of suckermouth armored catfishes. They are native to South America and Panama. Taxonomy ''Lasiancistrus'' was first described as a subgenus of ''Ancistrus'' in 1904, including ''A. heteracanthus'', ''A. pictus'', '' ...

'' in 1983. It was subsequently transferred to '' Guyanancistrus'', then to ''

Pseudancistrus ''Pseudancistrus'' is a genus of suckermouth armored catfishes native to South America. Taxonomy ''Pseudancistrus'' is a genus in the tribe Ancistrini of the subfamily Hypostominae. It was described by Pieter Bleeker in 1862, and redescribed by ...

'', where it is still listed by sources such as

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.

. Despite this reclassification, a 2018 taxonomic review of ''Guyanancistrus'' recognized ''G. longispinis'' as a valid member of the genus.

References

{{Taxonbar, from=Q6410526 Hypostominae Fish described in 1983 Fish of French Guiana