Species of catfish
 ;templatestyles src="Template:Taxobox/core/styles.css" / ;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 with rocky substrates and moderate levels of illumination. It is known to occur alongside the species "Guyanancistrus brevispinis", "Harttia fowleri", and "Crenicichla ternetzi", as well as members of the genus "Ancistrus". The species reaches 10.4 cm (4.1 inches) in standard length and may be a facultative air-breather.
"Guyanancistrus longispinis" was initially described as a species of "Lasiancistrus" in 1983. It was subsequently transferred to "Guyanancistrus", then to "Pseudancistrus", where it is still listed by sources such as FishBase. Despite this reclassification, a 2018 taxonomic review of "Guyanancistrus" recognized "G. longispinis" as a valid member of the genus.
References.
 ;templatestyles src="Reflist/styles.css" / ;