Hypancistrus is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of Loricariid catfish

Catfish

Catfishes are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...

 originating from the Amazon basin

Amazon Basin

The Amazon Basin is the part of South America drained by the Amazon River and its tributaries that drains an area of about , or roughly 40 percent of South America. The basin is located in the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, and Venezuela...

 in South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

. Unlike many of the other Loricariids, however, some Hypancistrus species are more carnivorous and enjoy meat in their diet. Hypancistrus species are popular aquarium

Aquarium

An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...

 fish, including such popular fish as the zebra pleco

Zebra Pleco

Hypancistrus zebra, gets its name from its black and white stripes, resembling the colouration of a zebra. It is a species of catfish endemic to the Big Bend area of the Xingu River, a tributary of the Amazon River, and was first described in the early 1990s. This fish was exported from Brazil in...

 and Queen Arabesque pleco.

Taxonomy

This genus is a relatively recent one, described in 1991 with its type species H. zebra. H. inspector was the next species to be described in 2002. In 2007, four new species of Hypancistrus were described. However, there are still many more undescribed species. These undescribed species are often designated with L-number

L-number

The L-number system is a semi-scientific classification system of catfish based on photographs of shipments of tropical catfish of the family Loricariidae published by the aquarium magazine DATZ ....

s. It was believed that this genus isn't monophyletic, though this has since changed.

Distribution and habitat

H. zebra originates from the Xingu River

Xingu River

The Xingu River , also called Rio Xingu, is a 1,230-mile long, river in north Brazil; it is a southeast tributary of the Amazon River.-Description and history:...

. Hypancistrus are also known from the Orinoco River and the Rio Negro. The rest of the described species originate from Venezuela

Venezuela

Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...

; the four new species alone originate from the northern Orinoco in southern Venezuela, near or in the Ventuari River

Ventuari River

The Ventuari River is a river in the Orinoco basin in Venezuela. The Ventuari flows from eastern Venezuela in the Guiana Highlands southwest into the Orinoco River. It is 520 km long and its major tributary is the Manapiare River.-References:...

. New species await to be described from regions such as Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

 and Guyana

Guyana

Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...

.

These fish are found in slow to moderately flowing water. They like to inhabit the bedrock and crevices within bedrock.

Anatomy and appearance

Hypancistrus, like other Loricariids, are armored catfish with a suckermouth

Suckermouth

In fishes, a suckermouth is a ventrally-oriented mouth adapted for grazing on algae and small organisms that grow on submerged objects....

. This suckermouth allows the fish to attach to objects. Their body is armored by scutes rather than covered in scales

Fish anatomy

Fish anatomy is primarily governed by the physical characteristics of water, which is much denser than air, holds a relatively small amount of dissolved oxygen, and absorbs more light than air does.- Body :...

. These fish have strong pectoral and dorsal fin spines. The eye

Eye

Eyes are organs that detect light and convert it into electro-chemical impulses in neurons. The simplest photoreceptors in conscious vision connect light to movement...

 is specially developed with an omega iris. The body is flat on the ventral surface and naked (scaleless).

Hypancistrus species can be differentiated from other genera of Loricariids by a number of characteristics. These fish have highly-angled jaw

Jaw

The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of...

s that form an angle

Angle

In geometry, an angle is the figure formed by two rays sharing a common endpoint, called the vertex of the angle.Angles are usually presumed to be in a Euclidean plane with the circle taken for standard with regard to direction. In fact, an angle is frequently viewed as a measure of an circular arc...

 of less than 90 degree

Degree (angle)

A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...

s, which is a trait shared only by a few other genera. Also, their scutes are not highly ridged or keeled like that of some genera, and their abdomen is only half-plated with this armor as opposed to full-plated. Hypancistrus have fewer dentary teeth than premaxilla

Premaxilla

The incisive bone is the portion of the maxilla adjacent to the incisors. It is a pair of small cranial bones at the very tip of the jaws of many animals, usually bearing teeth, but not always. They are connected to the maxilla and the nasals....

ry teeth, and the former are almost twice as long as the latter. Fish of this genus tend to be attractively marked with dark brown to black and white, arranged in spots, stripes, or squiggles. Breeding males have larger odontode

Odontode

Odontodes, or dermal teeth, are hard structures found on the external surfaces of animals or near internal openings. They comprise a soft pulp surrounded by dentine and covered by a mineralized substance such as enamel, a structure similar to that of teeth. They generally do not have the same...

s 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

Peckoltia

Peckoltia is a genus of small South American armored suckermouth catfishes. Many of these fish are popular aquarium fish.-Taxonomy:Peckoltia is a basal genus within the tribe Ancistrini of the subfamily Hypostominae. This genus is paraphyletic...

. Synapomorphies

Synapomorphy

In cladistics, a synapomorphy or synapomorphic character is a trait that is shared by two or more taxa and their most recent common ancestor, whose ancestor in turn does not possess the trait. A synapomorphy is thus an apomorphy visible in multiple taxa, where the trait in question originates in...

 of this genus include differences in the jaw structure from other Loricariids. These fish do not get very large; no species exceeds about 11 centimetres (4 in).

The different species of Hypancistrus are distinguishable by differences in their stripe, band, or spot patterns. 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 sidesways 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. 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. 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 together 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 both H. contradens and H. lunaorum. 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.

Diet

Hypancistrus are unusual in that some species accept meatier foods than many of their relatives, and are generally omnivorous; H. zebra is often cited as a fish that likes to accept meatier foods. Some other members of the genus tend to eat more plant material; H. inspector has been studied to eat algae

Algae

Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

, detritus

Detritus

Detritus is a biological term used to describe dead or waste organic material.Detritus may also refer to:* Detritus , a geological term used to describe the particles of rock produced by weathering...

, and also seed

Seed

A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

s. H. contradens is noted to probably feed on aufwuchs

Aufwuchs

Aufwuchs is a term used to cover the small animals and plants that encrust hard substrates, such as rocks, in aquatic environments. The name originated as a German term literally meaning "surface growth" or "overgrowth", and is frequently mis-spelled "awfuchs" or similar due to the unusual "-ufw-"...

; their guts have been shown to contain filamentous algae as well as various organic and inorganic matter.

In the aquarium

Many Hypancistrus are popular aquarium

Aquarium

An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...

 fish due to their small size and attractive coloration. Because of their more carnivorous diet, these fish are not like the algae eater

Algae eater

Algae eater is a common name for many bottom-dwelling fish that feed on algae. Algae eaters are important for the fishkeeping hobby and many are commonly kept by hobbyists.Some of the common and most popular freshwater algae eaters include:...

s aquarists are used to. These fish should be provided with clean, fast-moving water. They can be maintainted 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.

Below is a list of the described Hypancistrus with their L-number

L-number

The L-number system is a semi-scientific classification system of catfish based on photographs of shipments of tropical catfish of the family Loricariidae published by the aquarium magazine DATZ ....

s, 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.

L-number L-number The L-number system is a semi-scientific classification system of catfish based on photographs of shipments of tropical catfish of the family Loricariidae published by the aquarium magazine DATZ .... (s)	Common name Common name A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism... (s)	Scientific name
L004, L005, L028, L073	Angelicus pleco
L046, L098, L137	Zebra pleco Zebra Pleco Hypancistrus zebra, gets its name from its black and white stripes, resembling the colouration of a zebra. It is a species of catfish endemic to the Big Bend area of the Xingu River, a tributary of the Amazon River, and was first described in the early 1990s. This fish was exported from Brazil in... , Imperial pleco	H. zebra
L066	King tiger pleco, Scribbled pleco, Network pleco
L102	Snowball 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