{{Short description|Species of fish}} {{Speciesbox | image = Acanthicus adonis1.jpg | status = LC | status_system = IUCN3.1 | status_ref = <ref name = iucn>{{cite iucn|author=Salvador, G.N. |year=2023 |title= ''Acanthicus adonis'' |article-number= e.T164512501A164512505 |doi=10.2305/IUCN.UK.2023-1.RLTS.T164512501A164512505.en |access-date=5 March 2024}}</ref> | taxon = Acanthicus adonis | authority = Isbrücker & Nijssen, 1988<ref name = "Cof genus">{{Cof genus|genus=Acanthicus|access-date=24 May 2026}}</ref> }}
'''''Acanthicus adonis''''', the '''adonis pleco''' or '''polka dot lyre-tail pleco''', is a species of freshwater ray-finned fish belonging to the family Loricariidae, the suckermouth armoured catfishes, and the subfamily Hypostominae, the suckermouth catfishes.<ref name=PlanetCatfish>PlanetCatfish: ''[https://www.planetcatfish.com/common/species.php?species_id=277 Acanthicus adonis.]'' Retrieved 17 May 2013</ref><ref name=fishbase>{{FishBase |genus= Acanthicus|species= adonis| month = December| year = 2011}}</ref> This species is found in South America.
==Taxonomy== ''Acanthicus adonis'' was first formally described in 1988 by the Dutch ichthyologists Isaäc J. H. Isbrücker and Han Nijssen with its type locality given as Cametá on the Tocantins River at 0°14'S, 49°30.5'W in the Brazilian state of Pará.<ref name = "Cof genus"/> ''Eschmeyer's Catalog of Fishes'' classified the genus ''Acanthicus'' in the subfamily Hypostominae, the suckermouth catfishes, within the suckermouth armored catfish family Loricariidae.<ref name = "Cof family">{{Cof family|family=Hypostominae|access-date=24 May 2026}}</ref>
Individuals resembling the species have also been recorded from Amazonian Peru.<ref name=Chamon2016>Chamon, C.C. (2016): Redescription of ''Acanthicus hystrix'' Agassiz, 1829 (Siluriformes: Loricariidae), with comments on the systematics and distribution of the genus. Zootaxa, 4088 (3): 395–408.</ref><ref name=SeriouslyFish>{{cite web| title=''Acanthicus adonis'' | url=https://www.seriouslyfish.com/species/acanthicus-adonis/ | publisher=SeriouslyFish | access-date=31 October 2017}}</ref>
==Etymology== ''Acanthicus adonis'' is classified in the genus ''Acanthicus'' which is derived from the Greek ''akánthinos'', meaning "thorny", alluding to entire upper surface of the head of ''A. hystrix'', the type species, being armed with long erectile odontodes. The specific name, ''adonis'', is from Greek mythology, where Adonis was a handsome young man loved by the goddess Aphrodite, here referring to the attractive spotted juvenile colour pattern.<ref name = ETYFish>{{cite web |url=https://etyfish.org/hypostominae/ |title=Family LORICARIIDAE: Subfamily HYPOSTOMINAE Kner 1853 (Suckermouth Catfishes or Plecos) |date=18 January 2026 |access-date=24 May 2026 |author=Christopher Scharpf |work=The ETYFish Project Fish Name Etymology Database |publisher=Christopher Scharpf}}</ref>
==Appearance== ''Acanthicus adonis'' is among the largest armored catfish species and reaches a length of {{convert|1|m|ft|abbr=on}}.<ref name=PlanetCatfish/><ref name=SeriouslyFish/>
It is dark brown to black with numerous white spots as a juvenile. As the fish matures, the spots become less numerous and smaller, often disappearing entirely in large adults.<ref name=PlanetCatfish/><ref name=SeriouslyFish/> Its close relative ''A. hystrix'' always lack white spots, regardless of age.<ref name=Chamon2016/><ref name="Chamon2011">{{cite thesis|url=https://www.teses.usp.br/teses/disponiveis/41/41133/tde-13072012-101458/publico/CArine_Chamon.pdf|title=Revisão taxonômica e relações filogenéticas do grupo Acanthicus (Siluriformes, Loricariidae)|author=Chamon, C.C.|year=2011|publisher=São Paulo State University|doi=10.11606/T.41.2012.tde-13072012-101458|degree=PhD }}</ref> In contrast, ''A. adonis'' lacks the vermiculated pattern often (but not always) found on the underparts of ''A. hystrix''.<ref name=Chamon2016/><ref name=Chamon2011/>
==Distribution and habitat== Acanthicus adonis is found in South America where it has been recorded from the Tocantins River basin in Brazil, in the Solimões River at the triple border between Brazil, Colombia and Peru, and in the Yujo River basin, part of the Ucayali River basin, in Peru. This catfish is found in white and clear water rivers where it is a demersal species.<ref name = iucn/> These fish are opportunistic omnivores.<ref name=PlanetCatfish/>
==Utilisation== ''Acanthicus adonis'' is occasionally seen in the aquarium trade, but its massive adult size and territorially aggressive behavior means that a very large tank is required.<ref name=SeriouslyFish/><ref name=PlanetCatfish/>
== References == {{Commons category}} {{Reflist}}
{{Taxonbar|from=Q520259}}
adonis Category:Fish of the Amazon basin Category:Fish of the Tocantins River basin Category:Suckermouth catfish of Brazil Category:Fish described in 1988
{{Hypostominae-stub}}