Hypancistrus

{{Short description|Genus of fishes}} {{Automatic taxobox | image = Hypancistrus zebra4305.jpg | image_caption = ''Hypancistrus zebra'' | taxon = Hypancistrus | authority = Isbrücker & Nijssen, 1991 | type_species = ''Hypancistrus zebra'' | type_species_authority = Isbrücker & Nijssen, 1991 }}

'''''Hypancistrus''''' is a genus of loricariid catfish originating from the Amazon basin in South America. Unlike many of the other loricariids, some ''Hypancistrus'' species have carnivorous tendencies and enjoy meat in their diet. Many ''Hypancistrus'' species are popular aquarium fish.<ref name=Fishbase>{{FishBase genus | genus = Hypancistrus | year = 2015 | month = October }}</ref>

==Etymology== The name ''Hypancistrus'' is derived from two Greek terms: "hypo", which means "under", and "agkistron", which means "hook".<ref name=Fishbase/>

==Taxonomy== This genus is a relatively recent one: it was erected in 1991 when ''H. zebra'' was described.<ref name="Fishbase" /> ''H. inspector'' was the next species to be described in 2002,<ref name="Armbruster2002">{{cite journal |author=Armbruster, J.W. | year = 2002 | title = ''Hypancistrus inspector'': A New Species of Suckermouth Armored Catfish (Loricariidae: Ancistrinae) | journal = Copeia | volume = 2002 | issue = 1 | pages=86–92 | doi=10.1643/0045-8511(2002)002[0086:hianso]2.0.co;2| s2cid = 85580357 }}</ref> followed by four more species described in 2007.<ref name="alt">{{cite journal |author=Armbruster, J.W. |author2=Lujan, N.K. |author3=Taphorn, D.C. | year = 2007 | title = Four New Hypancistrus (Siluriformes: Loricariidae) from Amazonas, Venezuela | journal = Copeia | volume = 2007 | issue = 1 | pages = 62–79 | url = http://www.auburn.edu/academic/science_math/res_area/loricariid/fish_key/Hypanc/Hypancistrus4.pdf | doi=10.1643/0045-8511(2007)7[62:fnhslf]2.0.co;2| s2cid = 85617556 }}</ref> There are currently about a dozen described species in this genus, and there are many more undescribed ones, some designated with L-numbers.<ref name="arm">{{cite web |author=Armbruster, J. |title=''Hypancistrus'' |url=http://www.auburn.edu/academic/science_math/res_area/loricariid/fish_key/Hypanc/hypan.html}}</ref> It was believed that this genus was not monophyletic, though this has since changed.<ref name=alt/>

==Species== There are currently 11 recognized species in this genus:<ref>{{Cof genus|genus=Hypancistrus|access-date=5 September 2025}}</ref> * ''Hypancistrus contradens'' Armbruster, Lujan & Taphorn, 2007 * ''Hypancistrus debilittera'' Armbruster, Lujan & Taphorn, 2007 * ''Hypancistrus furunculus'' Armbruster, Lujan & Taphorn, 2007 * ''Hypancistrus inspector'' Armbruster, 2002 * ''Hypancistrus lunaorum'' Armbruster, Lujan & Taphorn, 2007 * ''Hypancistrus margaritatus'' M. Tan & Armbruster, 2016<ref name=Tan2016>{{cite journal |author1=Tan, M. |author2=Armbruster, J.W. | year = 2016 | title = Two new species of spotted ''Hypancistrus'' from the Rio Negro drainage (Loricariidae, Hypostominae) | journal = ZooKeys | issue = 552 | pages = 123–135 | url = https://zookeys.pensoft.net/articles.php?id=5956 | pmid=26865819 | doi=10.3897/zookeys.552.5956| pmc = 4740853 | doi-access = free |bibcode=2016ZooK..552..123T }}</ref> * ''Hypancistrus phantasma'' M. Tan & Armbruster, 2016<ref name=Tan2016/> * ''Hypancistrus seideli'' Sousa, Sousa, Oliveira, Sabaj Pérez, Zuanon & Rapp Py-Daniel, 2025 * ''Hypancistrus vandragti'' (Lujan & Armbruster, 2011) * ''Hypancistrus yudja'' Sousa, Sousa, Oliveira, Sabaj Pérez, Zuanon & Rapp Py-Daniel, 2025 * ''Hypancistrus zebra'' Isbrücker & Nijssen, 1991 (Zebra pleco)

==Distribution and habitat== ''Hypancistrus'' species are known from the Xingu River, the Orinoco River and the Rio Negro.<ref name=arm/><ref name="zebra">{{FishBase|genus=Hypancistrus|species=zebra|month=October|year=2015}}</ref> Venezuela appears to be a hotspot; the four species described in 2007, for instance, originate from the northern Orinoco in southern Venezuela, near or in the Ventuari River.<ref name=PFK>{{cite journal|url=http://www.practicalfishkeeping.co.uk/pfk/pages/item.php?news=1214 |title=Four L-number plecs get names |author=Clarke, M. |journal=Practical Fishkeeping |year=2007 |archive-url=https://web.archive.org/web/20070318092803/http://www.practicalfishkeeping.co.uk/pfk/pages/item.php?news=1214 |archive-date=2007-03-18 }}</ref> New species await to be described from regions such as Brazil and Guyana.<ref name=Tan2016/>

These fish are found in water with slow to moderate flowing speeds. They inhabit the bedrock and crevices within bedrock.<ref name=PFK/>

==Anatomy and appearance== ''Hypancistrus'' species, like other loricariids, are armored (in scutes; scales are absent as with catfishes in general) and have a suckermouth, allowing them to attach to submerged objects. These fish have strong pectoral and dorsal fin spines, and the eye is specially developed, with an omega iris. The body is dorsoventrally flattened.

''Hypancistrus'' species can be differentiated from other genera of loricariids by a number of characteristics. For instance, these fish have highly angled jaws that form an angle of less than 90 degrees, which is a trait shared only by a few other genera.<ref name=Armbruster2002/> Also, their scutes are not highly ridged or keeled like that of some genera, and their abdomen is only half-plated with armor as opposed to full-plated.<ref name=arm/> ''Hypancistrus'' species have fewer dentary teeth than premaxillary teeth, and the former are almost twice as long as the latter.<ref name=alt/> Breeding males have larger odontodes on the pectoral fin spines and on the cheek, though in some species, breeding males also have hypertrophied odontodes on the lateral plates (like ''Peckoltia'' species).<ref name=arm/> Synapomorphies of this genus include differences in the jaw structure from other loricariids.<ref name=Armbruster2002/>

''Hypancistrus'' species do not get very large, with no species exceeding about 11 centimetres (4 in).<ref name="alt" /> They tend to be attractively marked, with dark brown to black and white spots, stripes, or squiggles.<ref name="arm" /> The exact pattern allows one to distinguish them from each other;<ref name="arm" /> concretely:

* ''H. zebra'' is distinguishable as a white fish with oblique, black stripes that extend from behind the head into the tail, with an obvious E turned sideways on its nose. * ''H. furunculus'' appears rather similar to ''H. zebra'', but it has a creamier color (rather than white) and it only has one oblique stripe rather than many.<ref name="alt" /> * ''H. furunculus'' and ''H. debilittera'' both have vertical stripes on the caudal fin. However, ''H. debilittera'' has a dark base color and white spots, bands, and vermiculations with an either weakly formed or absent E on the nose.<ref name="alt" /> * In ''H. inspector'', there are smaller spots on the head and larger spots on the body, and some of the spots on the upper caudal fin will join and form bands. * If the dorsal fin of ''H. inspector'' is pushed down, the dorsal fin does not reach the adipose fin, in contrast to ''H. contradens'' and ''H. lunaorum''.<ref name="alt" /> * ''H. lunaorum'' has very small, gold spots dotting its body and, if present, the spots on the head will be of the same size. * ''H. contradens'' has white or pink, similarly sized spots large that do not connect to form bands.<ref name="alt" /> * ''H. margaritatus'' is distinguished from all congeners by its color pattern of dense, small, light-colored spots on a dark base color. * ''H. phantasma'' can be distinguished from congeners by a color pattern consisting of a tan base coloration with black spots.<ref name="Tan2016" />

==Diet== ''Hypancistrus'' species are unusual in that some species (such as ''H. zebra'') accept meatier foods than many of their relatives, and are generally omnivorous.<ref name=Sanford>{{cite book | title = Aquarium Owner's Guide |author=Sanford, G. | publisher = DK Publishing | location = New York | date = 1999 | pages = [https://archive.org/details/aquariumownersgu00sand/page/40 40] | isbn = 0-7894-4614-6 | url-access = registration | url = https://archive.org/details/aquariumownersgu00sand/page/40 }}</ref> Some other members of the genus tend to eat more plant material; ''H. inspector'' is known to eat algae, detritus, and also seeds.<ref name=Armbruster2002/><ref>{{FishBase | genus = Hypancistrus | species = inspector | month = October | year = 2015 }}</ref> ''H. contradens'' is noted to probably feed on aufwuchs; their guts have been shown to contain filamentous algae as well as various organic and inorganic matter.<ref name=PFK/>

==In the aquarium== Many ''Hypancistrus'' species are popular aquarium fish due to their small size and attractive coloration. Because of their more carnivorous diet, these fish are not like the algae eaters aquarists are used to.<ref name=Sanford/> These fish should be provided with clean, fast-moving water. They can be maintained in community aquariums, but quieter cohabitants are preferred so that these fish are not scared into hiding. Members of this genus have been captive bred by hobbyists.<ref name=Sanford/>

Below is a list of the described ''Hypancistrus'' with their L-numbers, as well as some undescribed types with common names that appear in the aquarium trade. There are many ''Hypancistrus'' only designated by their L-number that are not included.<ref name=pc>{{cite web | url = http://www.planetcatfish.com/catelog/numbers.php?mode=l&thumbs=16&start=0&genus_id=7 | title = ''Hypancistrus'' L-numbers | publisher = PlanetCatfish.com }}</ref> ''H. phantasma'' is not designated by L-numbers because this species is only known from holotype and paratypes caught on 14 February 1924 from Taracuá, Río Uaupés a tributary of the Río Negro drainage.<ref name=Tan2016/>

{| class="wikitable" |- |L-number(s) || Common name(s) || Scientific name |- | L004, L005, L028, L073 || Angelicus pleco || |- | L046, L098, L137 || Zebra pleco, Imperial pleco || ''H. zebra'' |- | L066 / L333 || King tiger pleco,<ref>{{Cite book |last=Alderton |first=David |title=Encyclopedia of Aquarium and Pond Fish |publisher=Dorling Kindersley Limited |year=2019 |isbn=978-0-241-44442-9 |location=London |page=130 |language=English}}</ref> Scribbled pleco, Network pleco || |- | L102 || Snow-ball pleco || ''H. inspector'' |- | L129 || || ''H. debilittera'' |- | L199 || || ''H. furunculus'' |- | L201 || || ''H. contradens'' |- | L260 || Queen Arabesque pleco || |- | L262 || Spotted Queen Arabesque, Salt Queen || |- | L270, L307 || Chocolate zebra pleco, Tapajos zebra pleco || |- | L339 || || ''H. lunaorum'' |- | L404 || || ''H. margaritatus'' |- | |}

==References== {{Reflist}}

Category:Ancistrini Category:Fish of the Amazon basin Category:Fish of South America Category:Catfish genera Category:Taxa named by Isaäc J. H. Isbrücker Category:Taxa named by Han Nijssen Category:Freshwater fish genera