View source for Ancistrus

{{Short description|Genus of fishes}}
{{Automatic taxobox
| image = Ancistrus sp. (aka).jpg
| image_upright= 1.1
| image_caption = ''Ancistrus sp.''
| taxon = Ancistrus
| authority = [[Rudolf Kner|Kner]], 1854
| type_species = ''Hypostomus cirrhosus''
| type_species_authority = Valenciennes, 1836
| synonyms = {{plainlist|
* ''Pristiancistrus'' <small>Fowler, 1945</small>
* ''Thysanocara'' <small>Regan, 1906</small>
* ''Xenocara'' <small>Regan, 1904</small>
}}
}}

'''''Ancistrus''''' is a [[genus]] of [[freshwater fish|nocturnal freshwater fish]] in the [[family (biology)|family]] [[Loricariidae]] of order [[Siluriformes]], native to freshwater habitats in [[South America]] and [[Panama]]. Fish of this genus are common in the [[aquarium]] trade where they are known as '''bushynose''' or '''bristlenose catfish'''. In the aquarium hobby they are often referred to as bushynose or bristlenose plecos instead, but this may lead to confusion as "pleco" usually is used for ''[[Hypostomus plecostomus]]'' and its allies and is often used as a catchall term for any loricariids remotely resembling that species.

==Taxonomy==
The [[type species]] is ''Ancistrus cirrhosus''.<ref name=fishbase>{{FishBase genus|genus=Ancistrus|year=2016|month=January}}</ref> This genus is the largest genus within the [[tribe (biology)|tribe]] [[Ancistrini]].<ref name="Armbruster"/>

The name ancistrus derives from the [[Ancient Greek]] ''agkistron'' "hook"&nbsp;– a reference to the form of the cheek [[odontodes]]. The genera ''Pristiancistrus'', ''Thysanocara'' and ''Xenocara'' are now synonyms of ''Ancistrus''.<ref name="Armbruster"/>

==Description==
[[Image: Ancistrus cirrhosus.jpg|thumb|left|''Ancistrus cirrhosus'']]
[[Image:Ancistrus 3 PiaH.jpg|thumb|''Ancistrus'' sp.]]
''Ancistrus'' species show all the typical features of the Loricariidae. This includes a body covered in bony plates and a ventral [[suckermouth]].<ref name="Sabaj"/> The feature most commonly associated with the genus are the fleshy tentacles found on the head in adult males; females may possess tentacles along the snout margin but they are smaller and they lack tentacles on the head.<ref name="Sabaj">{{cite journal|url=http://www.auburn.edu/academic/science_math/res_area/loricariid/fish_key/Ancistrus.pdf|title=Spawning in ''Ancistrus'' (Siluriformes: Loricariidae) with comments on the evolution of snout tentacles as a novel reproductive strategy: larval mimicry |author=Sabaj, M.H. |author2=Armbruster, J.W. |author3=Page, L.M. |journal=Ichthyological Explorations of Freshwaters|volume=10|issue=3|pages=217–229|year=1999}}</ref> ''Tentacules'', tentacles directly associated with [[odontode]]s, develop on the [[pectoral fin]] spine of the males of some species.<ref name="Sabaj"/> Males also have evertible cheek odontodes which are less developed or absent in females. They also lack odontodes along the snout.<ref name="Armbruster">{{cite web|url=http://www.auburn.edu/academic/science_math/res_area/loricariid/fish_key/Ancistrus/ancistrus.html|title=''Ancistrus'' Kner, 1854|last=Armbruster|first=J.W.}}</ref> In comparison with a typical loricariid (pleco), a bristlenose is typically shorter (4–6 inches or 15&nbsp;cm or less), more flattened and fatter with a comparatively wider head. Colouration is typically mottled brown, grey or black. Small white or yellow spots are common.<ref name="Armbruster"/> In contrast to many other loricariid 'plecos' (many of which regularly exceed a foot in captivity), the bristlenose plecos do not usually exceed six inches in length; they can thus be kept in relatively small tanks, contributing to their popularity in the aquarium hobby.

''Ancistrus'' species are unusual among vertebrates in possessing an [[X0 sex-determination system]], which is the prevailing method in many lineages of [[arthropod]] but is very rare elsewhere in the animal kingdom.<ref>Anderson, Luís Alves; Oliveira, Claudio; Nirchio, Mauro; Granado, Ángel and Foresti, Fausto; 'Karyotypic relationships among the tribes of Hypostominae (Siluriformes: Loricariidae) with description of XO sex chromosome system in a Neotropical fish species'; Genetica, vol. 128 (2006); pp. 1–9</ref>

==Distribution and habitat==
''Ancistrus'' is one of the widest ranging Loricariid genera, and representatives are found in most areas where the family in general is present.<ref name="Armbruster"/> Many species are found in the rivers and floodplain areas of the [[Amazon basin]], but there are also species elsewhere in tropical South America, as well as species on the island of [[Trinidad]] and two species, ''A.&nbsp;centrolepis'' and ''A.&nbsp;chagresi'' in [[Panama]].<ref name=Taphorn2013/> Three species are true [[cavefish]] ([[troglobites]]): ''A.&nbsp;cryptophthalmus'', ''A.&nbsp;galani'' and ''A.&nbsp;formoso''.<ref name=cave>Romero, A. (2001): ''The Biology of Hypogean Fishes.'' Developments in Environmental Biology of Fishes. {{ISBN|978-1-4020-0076-8}}</ref><ref name="Trajano">{{cite journal|journal=Environmental Biology of Fishes|volume=62|issue=1|pages=195–200|year=2001|title=Habitat and Population Data of Troglobitic Armored Cave Catfish, ''Ancistrus cryptophthalmus'' Reis, 1987, from Central Brazil (Siluriformes: Loricariidae)|first=E.|last=Trajano|doi=10.1023/A:1011884829498|bibcode=2001EnvBF..62..195T |s2cid=22106285 }}</ref> These are the only known loricariids that possess adaptions for a subterranean lifestyle, such as reduced [[Biological pigment|pigmentation]] (appearing overall whitish) and eyes.<ref name=cave/>

==Aquarium maintenance==
In the wild, ''Ancistrus'' species prefer flowing water, so tanks with flow are typically used when keeping them in captivity. Since they are bottom-dwelling fish, substrate is considered preferable to a bare tank floor. Mixtures of gravel, dirt, and clay are frequently used as substrate for ''Ancistrus''. 

The aquarium size that is considered by some to be a minimum for fish of this genus is 25 gallons.<ref>{{Cite web |last=Andrew Pete |date=2021-07-20 |title=Bristlenose Pleco Care: Size, Lifespan, Tank Mates, Tank Size and Setup |url=https://fishkeepingproject.com/bristlenose-pleco-care/ |access-date=2022-04-08 |website=Fishkeeping Project |language=en-US |url-status=usurped |archive-url=https://web.archive.org/web/20220408154927/https://fishkeepingproject.com/bristlenose-pleco-care/ |archive-date=2022-04-08}}</ref>{{SPS|date=April 2024}}

==Species==
There are currently 76 recognized species in this genus:<ref>{{cite web |url=http://novataxa.blogspot.com/2019/02/ancistrus-patronus.html|title=Review of Ancistrus (Siluriformes: Loricariidae) from the northwestern Guiana Shield, Orinoco Andes, and Adjacent Basins with Description of Six New Species|date=8 February 2019 |publisher=Novataxa |access-date=11 February 2019}}</ref>
{{columns-list|colwidth=30em|
* ''[[Ancistrus abilhoai]]'' <small>[[Alessandro Gasparetto Bifi|Bifi]], [[Carla Simone Pavanelli|Pavanelli]] & [[Cláudio Henrique Zawadzki|Zawadzki]], 2009</small>
* ''[[Ancistrus agostinhoi]]'' <small>[[Alessandro Gasparetto Bifi|Bifi]], [[Carla Simone Pavanelli|Pavanelli]] & [[Cláudio Henrique Zawadzki|Zawadzki]], 2009</small>
* ''[[Ancistrus aguaboensis]]'' <small>[[Sonia Fisch-Muller|Fisch-Muller]], [[Rosana Mazzoni Buchas|Mazzoni]] & [[Claude Weber|C. Weber]], 2001</small>
* ''[[Ancistrus amaris]]'' <small>[[Lesley S. de Souza]], [[Donald Charles Taphorn Baechle|Taphorn]] & [[Jonathan W. Armbruster|Armbruster]], 2019</small>
* ''[[Ancistrus bodenhameri]]'' <small>[[Leonard Peter Schultz|L. P. Schultz]], 1944</small>
* ''[[Ancistrus bolivianus]]'' <small>([[Franz Steindachner|Steindachner]], 1915)</small>
* ''[[Ancistrus brevifilis]]'' <small>([[Carl H. Eigenmann|C. H. Eigenmann]], 1920)</small>
* ''[[Ancistrus brevipinnis]]'' <small>([[Charles Tate Regan|Regan]], 1904)</small>
* ''[[Ancistrus bufonius]]'' <small>([[Achille Valenciennes|Valenciennes]], 1840)</small>
* ''[[Ancistrus caucanus]]'' <small>[[Henry Weed Fowler|Fowler]], 1943</small>
* ''[[Ancistrus centrolepis]]'' <small>[[Charles Tate Regan|Regan]], 1913</small>
* ''[[Ancistrus chagresi]]'' <small>[[Carl H. Eigenmann|C. H. Eigenmann]] & [[Rosa Smith Eigenmann|R. S. Eigenmann]], 1889</small>
* ''[[Ancistrus cirrhosus]]'' <small>([[Achille Valenciennes|Valenciennes]], 1836)</small>
* ''[[Ancistrus claro]]'' <small>[[Joachim Knaack|Knaack]], 1999</small>
* ''[[Ancistrus clementinae]]'' <small>[[Carl Hialmar Rendahl|Rendahl]] ([[:de:Hialmar Rendahl|de]]), 1937</small>
* ''[[Ancistrus cryptophthalmus]]'' <small>[[Roberto Esser dos Reis|R. E. dos Reis]], 1987</small>
* ''[[Ancistrus cuiabae]]'' <small>[[Joachim Knaack|Knaack]], 1999</small>
* ''[[Ancistrus damasceni]]'' <small>([[Franz Steindachner|Steindachner]], 1907)</small>
* ''[[Ancistrus dolichopterus]]'' <small>[[Rudolf Kner|Kner]], 1854</small> (Bushy-mouth catfish)
* ''[[Ancistrus dubius]]'' <small>[[Carl H. Eigenmann|C. H. Eigenmann]] & [[Rosa Smith Eigenmann|R. S. Eigenmann]], 1889</small>
* ''[[Ancistrus erinaceus]]'' <small>([[Achille Valenciennes|Valenciennes]], 1840)</small>
* ''[[Ancistrus eustictus]]'' <small>([[Henry Weed Fowler|Fowler]], 1945)</small>
* ''[[Ancistrus falconensis]]'' <small>[[Donald Charles Taphorn Baechle|Taphorn]], [[Jonathan W. Armbruster|Armbruster]] & [[Douglas Rodríguez-Olarte|Rodríguez-Olarte]], 2010</small>
* ''[[Ancistrus formoso]]'' <small>[[José Sabino|Sabino]] & [[Eleonora Trajano|Trajano]], 1997</small>
* ''[[Ancistrus fulvus]]'' <small>([[Maximillian Holly|Holly]], 1929)</small>
* ''[[Ancistrus galani]]'' <small>[[Alfredo Pérez Lozano|A. Pérez]] & [[Ángel Luis Viloria Petit|Viloria]], 1994</small>
* ''[[Ancistrus greeni]]'' <small>([[Isaäc J. H. Isbrücker|Isbrücker]], 2001)</small><ref name=Lujan2015>{{cite journal |last1=Lujan |first1=Nathan K. |last2=Meza-Vargas |first2=Vanessa |last3=Astudillo-Clavijo |first3=Viviana |last4=Barriga-Salazar |first4=Ramiro |last5=López-Fernández |first5=Hernán |title=A Multilocus Molecular Phylogeny for Chaetostoma Clade Genera and Species with a Review of Chaetostoma (Siluriformes: Loricariidae) from the Central Andes |journal=Copeia |date=September 2015 |volume=103 |issue=3 |pages=664–701 |doi=10.1643/CI-14-194 }}</ref>
* ''[[Ancistrus gymnorhynchus]]'' <small>[[Rudolf Kner|Kner]], 1854</small>
* ''[[Ancistrus heterorhynchus]]'' <small>([[Charles Tate Regan|Regan]], 1912)</small>
* ''[[Ancistrus hoplogenys]]'' <small>([[Albert Günther|Günther]], 1864)</small>
* ''[[Ancistrus jataiensis]]'' <small>[[Sonia Fisch-Muller|Fisch-Muller]], [[Alexandre Rodrigues Cardoso|A. R. Cardoso]], [[José Francisco Pezzi da Silva|J. F. P. da Silva]] & [[Vinicius de Araújo Bertaco|Bertaco]], 2005</small>
* ''[[Ancistrus jelskii]]'' <small>([[Franz Steindachner|Steindachner]], 1877)</small>
* ''[[Ancistrus karajas]]'' <small>[[Renildo Ribeiro de Oliveira|R. R. de Oliveira]], [[Lúcia Helena Rapp Py-Daniel|Rapp Py-Daniel]], [[Cláudio Henrique Zawadzki|Zawadzki]] & [[Jansen Alfredo Sampaio Zuanon|Zuanon]], 2016</small><ref name=Oliveia2016>{{cite journal |last1=de Oliveira |first1=R.R. |last2=Rapp Py-Daniel |first2=L. |last3=Zawadzki |first3=C.H. |last4=Zuanon |first4=J. |date=2016 |title=Two new Amazonian species of ''Ancistrus'' with vestigial adipose fin, with an appraisal on adipose fin loss in neotropical armoured catfishes (Teleostei: Loricariidae) |journal=Ichthyological Exploration of Freshwaters |volume=27 |issue=1 |pages=67–80 |url=https://pfeil-verlag.de/wp-content/uploads/2016/07/ief27_1_07.pdf }}</ref>
* ''[[Ancistrus kellerae]]'' <small>[[Lesley S. de Souza]], [[Donald Charles Taphorn Baechle|Taphorn]] & [[Jonathan W. Armbruster|Armbruster]], 2019</small>
* ''[[Ancistrus krenakarore]]'' <small>[[Renildo Ribeiro de Oliveira|R. R. de Oliveira]], [[Lúcia Helena Rapp Py-Daniel|Rapp Py-Daniel]], [[Cláudio Henrique Zawadzki|Zawadzki]] & [[Jansen Alfredo Sampaio Zuanon|Zuanon]], 2016</small><ref name=Oliveia2016/>
* ''[[Ancistrus latifrons]]'' <small>([[Albert Günther|Günther]], 1869)</small>
* ''[[Ancistrus leoni]]'' <small>[[Lesley S. de Souza]], [[Donald Charles Taphorn Baechle|Taphorn]] & [[Jonathan W. Armbruster|Armbruster]], 2019</small>
* ''[[Ancistrus leucostictus]]'' <small>([[Albert Günther|Günther]], 1864)</small>
* ''[[Ancistrus lineolatus]]'' <small>[[Henry Weed Fowler|Fowler]], 1943</small>
* ''[[Ancistrus lithurgicus]]'' <small>[[Carl H. Eigenmann|C. H. Eigenmann]], 1912</small>
* ''[[Ancistrus macrophthalmus]]'' <small>([[Jacques Pellegrin|Pellegrin]], 1912)</small>
* ''[[Ancistrus maculatus]]'' <small>([[Franz Steindachner|Steindachner]], 1881)</small>
* ''[[Ancistrus malacops]]'' <small>([[Edward Drinker Cope|Cope]], 1872)</small>
* ''[[Ancistrus maracasae]]'' <small>[[Henry Weed Fowler|Fowler]], 1946</small>
* ''[[Ancistrus marcapatae]]'' <small>([[Charles Tate Regan|Regan]], 1904)</small><ref name=Lujan2015/>
* ''[[Ancistrus martini]]'' <small>[[Leonard Peter Schultz|L. P. Schultz]], 1944</small>
* ''[[Ancistrus mattogrossensis]]'' <small>[[Alípio de Miranda-Ribeiro|A. Miranda-Ribeiro]], 1912</small>
* ''[[Ancistrus maximus]]'' <small>[[Renildo Ribeiro de Oliveira|R. R. de Oliveira]], [[Jansen Alfredo Sampaio Zuanon|Zuanon]], [[Cláudio Henrique Zawadzki|Zawadzki]] & [[Lúcia Helena Rapp Py-Daniel|Rapp Py-Daniel]], 2015</small><ref name=Oliveira2015>{{cite journal |last1=de Oliveira |first1=R.R. |last2=Zuanon |first2=J. |last3=Zawadzki |first3=C.H. |last4=Rapp Py-Daniel |first4=L. |date=2015 |title=''Ancistrus maximus'', a new species of red-dotted armored catfish from rio Branco, Roraima State, Brazilian Amazon (Siluriformes: Loricariidae) |journal=Ichthyological Exploration of Freshwaters |volume=26 |issue=1 |pages=73–82 |url=https://www.pfeil-verlag.de/wp-content/uploads/2016/07/ief26_1_05.pdf }}</ref>
* ''[[Ancistrus megalostomus]]'' <small>[[Nathan Everett Pearson|N. E. Pearson]], 1924</small>
* ''[[Ancistrus minutus]]'' <small>[[Sonia Fisch-Muller|Fisch-Muller]], [[Rosana Mazzoni Buchas|Mazzoni]] & [[Claude Weber|C. Weber]], 2001</small>
* ''[[Ancistrus montanus]]'' <small>([[Charles Tate Regan|Regan]], 1904)</small>
* ''[[Ancistrus mullerae]]'' <small>[[Alessandro Gasparetto Bifi|Bifi]], [[Carla Simone Pavanelli|Pavanelli]] & [[Cláudio Henrique Zawadzki|Zawadzki]], 2009</small>
* ''[[Ancistrus multispinis]]'' <small>([[Charles Tate Regan|Regan]], 1912)</small>
* ''[[Ancistrus nudiceps]]'' <small>([[Johannes Peter Müller|J. P. Müller]] & [[Franz Hermann Troschel|Troschel]], 1849)</small>
* ''[[Ancistrus occidentalis]]'' <small>([[Charles Tate Regan|Regan]], 1904)</small>
* ''[[Ancistrus occloi]]'' <small>[[Carl H. Eigenmann|C. H. Eigenmann]], 1928</small>
* ''[[Ancistrus parecis]]'' <small>[[Sonia Fisch-Muller|Fisch-Muller]], [[Alexandre Rodrigues Cardoso|A. R. Cardoso]], [[José Francisco Pezzi da Silva|J. F. P. da Silva]] & [[Vinicius de Araújo Bertaco|Bertaco]], 2005</small>
* ''[[Ancistrus patronus]]'' <small>[[Lesley S. de Souza]], [[Donald Charles Taphorn Baechle|Taphorn]] & [[Jonathan W. Armbruster|Armbruster]], 2019</small>
* ''[[Ancistrus piriformis]]'' <small>[[Sonia Fisch-Muller|Fisch-Muller]], 1989</small>
* ''[[Ancistrus ranunculus]]'' <small>[[Sonia Fisch-Muller|Fisch-Muller]], [[Lúcia Helena Rapp Py-Daniel|Rapp Py-Daniel]] & [[Jansen Alfredo Sampaio Zuanon|Zuanon]], 1994</small>
* ''[[Ancistrus reisi]]'' <small>[[Sonia Fisch-Muller|Fisch-Muller]], [[Alexandre Rodrigues Cardoso|A. R. Cardoso]], [[José Francisco Pezzi da Silva|J. F. P. da Silva]] & [[Vinicius de Araújo Bertaco|Bertaco]], 2005</small>
* ''[[Ancistrus saudades]]'' <small>[[Lesley S. de Souza]], [[Donald Charles Taphorn Baechle|Taphorn]] & [[Jonathan W. Armbruster|Armbruster]], 2019</small>
* ''[[Ancistrus sericeus]]'' <small>([[Edward Drinker Cope|Cope]], 1872)</small><ref name=Lujan2015/> 
* ''[[Ancistrus stigmaticus]]'' <small>[[Carl H. Eigenmann|C. H. Eigenmann]] & [[Rosa Smith Eigenmann|R. S. Eigenmann]], 1889</small>
* ''[[Ancistrus tamboensis]]'' <small>[[Henry Weed Fowler|Fowler]], 1945</small>
* ''[[Ancistrus taunayi]]'' <small>[[Alípio de Miranda-Ribeiro|A. Miranda-Ribeiro]], 1918</small>
* ''[[Ancistrus temminckii]]'' <small>([[Achille Valenciennes|Valenciennes]], 1840)</small>
* ''[[Ancistrus tolima]]'' <small>[[Donald Charles Taphorn Baechle|Taphorn]], [[Jonathan W. Armbruster|Armbruster]], [[Francisco Antonio Villa-Navarro|Villa-Navarro]] & [[C. Keith Ray|C. K. Ray]], 2013</small><ref name=Taphorn2013>{{cite journal |last1=Taphorn |first1=Donald C. |last2=Armbruster |first2=Jonathan W. |last3=Villa-Navarro |first3=Francisco |last4=Ray |first4=C. Keith |title=Trans-Andean Ancistrus (Siluriformes: Loricariidae) |journal=Zootaxa |date=26 April 2013 |volume=3641 |issue=4 |pages=343–370 |doi=10.11646/zootaxa.3641.4.2 |pmid=26287090 }}</ref>
* ''[[Ancistrus tombador]]'' <small>[[Sonia Fisch-Muller|Fisch-Muller]], [[Alexandre Rodrigues Cardoso|A. R. Cardoso]], [[José Francisco Pezzi da Silva|J. F. P. da Silva]] & [[Vinicius de Araújo Bertaco|Bertaco]], 2005</small>
* ''[[Ancistrus trinitatis]]'' <small>([[Albert Günther|Günther]], 1864)</small>
* ''[[Ancistrus triradiatus]]'' <small>[[Carl H. Eigenmann|C. H. Eigenmann]], 1918</small>
* ''[[Ancistrus variolus]]'' <small>([[Edward Drinker Cope|Cope]], 1872)</small>
* ''[[Ancistrus verecundus]]'' <small>[[Sonia Fisch-Muller|Fisch-Muller]], [[Alexandre Rodrigues Cardoso|A. R. Cardoso]], [[José Francisco Pezzi da Silva|J. F. P. da Silva]] & [[Vinicius de Araújo Bertaco|Bertaco]], 2005</small>
* ''[[Ancistrus vericaucanus]]'' <small>[[Donald Charles Taphorn Baechle|Taphorn]], [[Jonathan W. Armbruster|Armbruster]], [[Francisco Antonio Villa-Navarro|Villa-Navarro]] & [[C. Keith Ray|C. K. Ray]], 2013</small><ref name=Taphorn2013/>
* ''[[Ancistrus yutajae]]'' <small>[[Lesley S. de Souza]], [[Donald Charles Taphorn Baechle|Taphorn]] & [[Jonathan W. Armbruster|Armbruster]], 2019</small>
}}

==Ecology==
[[Image:Akwa21 ancistrus.jpg|thumb|Albino bristlenose catfish are common in the aquarium trade.]]
The diet of this genus is typical for a Loricariid&nbsp;– [[algae]], [[aufwuchs]], and detritus, with sediment, sand, and gravel presumably ingested accidentally alongside food items.<ref>{{cite journal |last1=Buck |first1=Sonia |last2=Sazima |first2=Ivan |date=1995 |title=An assemblage of mailed catfishes (Loricariidae) in southeastern Brazil: distribution, activity, and feeding |journal=Ichthyological Exploration of Freshwaters |volume=6 |issue=4 |pages=325–332 }}</ref><ref>{{cite journal |last1=Lujan |first1=Nathan K |last2=Winemiller |first2=Kirk O |last3=Armbruster |first3=Jonathan W |title=Trophic diversity in the evolution and community assembly of loricariid catfishes |journal=BMC Evolutionary Biology |date=2012 |volume=12 |issue=1 |pages=124 |doi=10.1186/1471-2148-12-124 |pmid=22835218 |pmc=3497581 |doi-access=free |bibcode=2012BMCEE..12..124L }}</ref><ref>{{cite journal |last1=Kramer |first1=Donald L. |last2=Bryant |first2=Michael J. |title=Intestine length in the fishes of a tropical stream: 2. Relationships to diet — the long and short of a convoluted issue |journal=Environmental Biology of Fishes |date=February 1995 |volume=42 |issue=2 |pages=129–141 |doi=10.1007/BF00001991 |bibcode=1995EnvBF..42..129K |s2cid=33113299 }}</ref><ref>{{cite journal |last1=Vucko |first1=Matthew J. |last2=Cole |first2=Andrew J. |last3=Moorhead |first3=Jonathan A. |last4=Pit |first4=Josiah |last5=de Nys |first5=Rocky |title=The freshwater macroalga Oedogonium intermedium can meet the nutritional requirements of the herbivorous fish Ancistrus cirrhosus |journal=Algal Research |date=November 2017 |volume=27 |pages=21–31 |doi=10.1016/j.algal.2017.08.020 |bibcode=2017AlgRe..27...21V }}</ref><ref>{{cite journal |last1=Power |first1=Mary E. |title=The importance of sediment in the grazing ecology and size class interactions of an armored catfish, Ancistrus spinosus |journal=Environmental Biology of Fishes |date=April 1984 |volume=10 |issue=3 |pages=173–181 |doi=10.1007/BF00001124 |bibcode=1984EnvBF..10..173P |s2cid=13343092 }}</ref><ref>{{cite journal |last1=Ibañez |first1=Carla |last2=Tedesco |first2=Pablo A. |last3=Bigorne |first3=Rémy |last4=Hugueny |first4=Bernard |last5=Pouilly |first5=Marc |last6=Zepita |first6=Claudia |last7=Zubieta |first7=José |last8=Oberdorff |first8=Thierry |title=Dietary-morphological relationships in fish assemblages of small forested streams in the Bolivian Amazon |journal=Aquatic Living Resources |date=April 2007 |volume=20 |issue=2 |pages=131–142 |doi=10.1051/alr:2007024 |hdl=10256/7795 |hdl-access=free }}</ref> Despite reports among fish-keepers that they require wood in their diet, no scientific evidence to date supports members of this genus feeding on wood.  Bristlenoses do not school but hide when not feeding, juveniles however are typically found in brightly lit shallows at the water margin making them susceptible to predation by birds.

''Ancistrus'' species have the capability of obtaining oxygen through their modified stomach.<ref name=stomach>{{cite journal |last1=Satora |first1=L |title=Histological and ultrastructural study of the stomach of the air-breathing Ancistrus multispinnis (Siluriformes, Teleostei) |journal=Canadian Journal of Zoology |date=January 1998 |volume=76 |issue=1 |pages=83–86 |doi=10.1139/z97-167 |bibcode=1998CaJZ...76...83S }}</ref> This allows them to survive in conditions with [[hypoxia (environmental)|low oxygen levels]].<ref name="Armbruster"/>

Breeding takes place in hollows, caves and mud holes in banks. Males may clean the inside of the cavity with their suckermouth before allowing the female to approach and inspect the nest.  [[courtship display|Courtship]] includes expanding the dorsal and caudal fins and attempts by the male to escort the female to the nest. While the female inspects the nest, the male keeps close contact.<ref name="Sabaj"/> The female may lay 20–200 adhesive eggs, usually to the ceiling of the cavity.<ref name="Sabaj"/>

The female plays no role in parental care; the male takes care of its young. Males will clean the eggs and the cavity with its fins and mouth. Males inspect eggs to remove diseased or infertile eggs, and aerates the clutch by fanning them with its pectoral and pelvic fins.<ref name="Sabaj"/> During this time, a male usually will not leave the cavity to feed, or will leave only occasionally and quickly return.<ref name="Sabaj"/> The eggs hatch in 4–10 days over a period of 2–6 hours; the male guards the eggs for 7–10 days after hatching.<ref name="Sabaj"/> The fry remain in the cave, attaching to the walls and ceiling with their mouths, absorbing their [[yolk]] sac in 2–4 days and becoming free swimming.<ref name="Sabaj"/>

Males of these species are competitive and territorial. Males display to each other by positioning themselves parallel to each other, head to tail, with dorsal and caudal fins erect and cheek odontode spines everted. If this escalates to combat, the males will circle each other and direct attacks at the head.<ref name="Sabaj"/> If an intruding male manages to evict another male from the nest, it may cannibalize the other male's young.<ref name="Sabaj"/>

A male bristlenose may guard several clutches of eggs simultaneously. Females prefer males that are already protecting eggs and may prefer males that are protecting larvae; it has been suggested that the tentacles may act as a fry [[mimic]] to attract females, which would allow males without eggs in their nest to compete with males guarding eggs.<ref name="Sabaj"/> Several clutches in various states of development from eggs to free-swimming larvae can be found in one nest.<ref name="Armbruster"/>

==In the aquarium==
[[Image:Ancistrus On Cucumber.jpg|250px|thumb|right|Female ''Ancistrus sp.'' on a piece of cucumber]]
These fish are often kept by aquarists, as they are dutiful algae-eaters and smaller in adult size than the [[common pleco]]s usually seen in pet shops. They reach up to {{Convert|15|cm|abbr=on}} in males, and {{Convert|12|cm|abbr=on}} in females. Their recommended temperature is {{Convert|23-27|C|abbr=on}}. Their lifespan is up to 12 years. They are hardy animals, tolerant to a wide range of water conditions. They breed easily in captivity, and are compatible with most other freshwater fish. Though typically mottled brown or black-and-grey spotted in color, other species are more exotic&nbsp;– spots of bright yellow on a dark background being a common pattern. Albino variants are also common. The albino morph is not caused by exposure to light during development, it is a morph controlled by genetics.<ref name="Green, D.">{{cite journal|author=Green, D.|year=2010|url=http://www.keepingandbreedingbristlenose.com/|journal=Aquatic Ecology|title=Keeping and Breeding Bristlenose|pages=688|access-date=2012-09-24|archive-date=2019-07-02|archive-url=https://web.archive.org/web/20190702005954/http://keepingandbreedingbristlenose.com/|url-status=dead}}</ref>

Historically, commonly available species of ''Ancistrus'' were ''[[Ancistrus cirrhosus]]'' and ''[[Ancistrus temminckii]]''; other species are now available, though exact identification is difficult.

Feeding is easy, bristlenoses will graze on algae/ algae wafers and other surface growing organisms as well as eating algae wafers or tablets, flake food, squash, spinach, cucumber, zucchini, green beans, peas and even sliced carrots. They have also been known to accept frozen bloodworms as part of their diet. Aquarium specimens may starve for lack of algae or other plant matter; algae wafers or other low-protein foods are recommended. Keepers should watch for the abdomen to take on a sunken appearance, indicating insufficient nutrition.

Sexing is very easy as the female will only occasionally have bristles, around the edge of the chin, whereas the male will have them up the center of the head.

Breeding is also possible. Males attract females to a small cave or hollow, then guard eggs after fertilization through hatching (4–8 days) until fry are free swimming (4–6 days after hatching); the aquarist need only supply a suitable cave, food, and one of each sex.

Caution should be taken with the spines (odontodes); although the risk of personal injury is small with this genus, the hooked nature of the odontodes means that a bristlenose may become trapped in non-natural material such as sponge filters and netting.

==See also==
* [[List of freshwater aquarium fish species]]

==References==
{{Reflist}}

{{Taxonbar|from=Q571923}}

[[Category:Ancistrus| ]]
[[Category:Ancistrini]]
[[Category:Taxa named by Rudolf Kner]]
[[Category:Catfish genera]]
[[Category:Freshwater fish genera]]