''Pseudorinelepis genibarbis'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of armored catfish native to Brazil, Peru and Ecuador where it is found in the Amazon basin.

Taxonomy

''Pseudorinelepis'' is one of three genera contained in the

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English is in the discipline of anthropology. This definition is contested, in part due to confli ...

Rhinelepini Rhinelepini is a tribe of fishes in the subfamily Hypostominae of the armored suckermouth catfish family Loricariidae. Taxonomy This tribe is a well diagnosed monophyletic group currently containing three genera: '' Pogonopoma'', '' Pseudorin ...

, one of the tribes of

Hypostominae The Hypostominae are a subfamily of catfishes of the family Loricariidae. Most members are restricted to tropical and subtropical South America, but there are also several species (in genera ''Ancistrus'', '' Chaetostoma'', ''Lasiancistrus'', '' ...

. ''Canthopomus'' and ''Monistiancistrus'' are synonyms of the genus ''Pseudorinelepis''. Previously, ''Pseudorinelepis'' was a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of four

, but now the other three species are synonymous with ''P. genibarbis''.

Appearance and anatomy

''P. genibarbis'' reaches a length of SL. They are a large, bulky Loricariid. The armor plates along the side of the fish are thick, are keeled, and encase the whole body. The

adipose fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

is not present. Like other members of Rhinelepini, they do not have the omega iris that is typical in most species of Loricariids. In Iquitos,

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = National seal , national_motto = "Firm and Happy f ...

, it is known as ''carachama sin costilla'', which actually means "Loricariid without ribs"; this refers to the trait that it shares with other Rhinelepini catfish that do not have ribs past the sixth vertebra. This species is highly variable in coloration. ''P. genibarbis'' may be completely dark brown to black, mottled with tan to dark brown background and black streaks, or light tan with large, sparse spots located at base of lateral plates, fin membranes, and abdomen. Males have longer

odontode Odontodes, or dermal teeth, are hard structures found on the external surfaces of animals or near internal openings. They consist of a soft pulp surrounded by dentine and covered by a mineralized substance such as enamel, a structure similar to th ...

s on the cheek that are denser and more numerous than in females. It has been suggested that breeding males may also have orange on the cheeks and

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal c ...

and

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

spines, although this may be restricted to fish from the Branco River.

Ecology

''P. genibarbis'' is found in small, sluggish streams, floodplain lakes, and large rivers. Water quality measurements showed that the water tended to be low in oxygen, but neutral ( pH 7.0). ''P. genibarbis'' is able to swallow air, like many other Loricariids. However, this species is not an obligate air-breather. When disturbed, it is able to swallow air to become neutrally buoyant and swim in the water column. Carachama_fish

In the aquarium

This species is an armored catfish which, since the 1990s, has started to be offered quite regularly as an aquarium

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

under the name "Pineapple Pleco". The term " pleco" here is of course a popular generalisation, as

taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

has never placed this fish in the former genus ''

Plecostomus Plecostomus, pleco, or plec is the common name of several species of freshwater loricariid catfish commonly sold as aquarium fish. These include: *''Hypostomus plecostomus'' *'' Hypostomus punctatus'' *'' Pterygoplichthys multiradiatus'' *'' Pte ...

''. The armour is also pleasantly spiked along the sides of the fish, which causes the

pineapple The pineapple (''Ananas comosus'') is a tropical plant with an edible fruit; it is the most economically significant plant in the family Bromeliaceae. The pineapple is indigenous to South America, where it has been cultivated for many centuri ...

resemblance celebrated in the commercial name of the species. Additionally, under the

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 German aquarium magazine DATZ (Die Aquarien- und Terrarienzeitschrift (The ...

system used by hobbyists, it as referred to as both L152 and L095. There is quite a degree of colour variation, which is probably the main reason for the confusion over species. Some males having orange cheeks, which is why "orange cheek Pleco" is another common name found in circulation. This is not made any easier by the fact that the fish will gradually darken if left in a tank with a darker substrate and lighten when kept on a lighter substrate. These changes take some time (hours or days) to effect, they do not happen quickly, so there is no real " chameleon" effect here, but no doubt it is a useful survival mechanism. From the viewpoint of the aquarist the fish is peaceful, sociable with others of its own type, non-territorial, omnivorous, but appears to require bogwood, which it gradually gnaws away, as part of its diet. The image above shows one engaged in gnawing bogwood. Unsurprisingly, therefore, they do well in soft water, although pH values of up to 7.5 are acceptable, and the

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measurement, measured with a thermometer. Thermometers are calibrated in various Conversion of units of temperature, temp ...

range may fluctuate gently between 23-27

°C The degree Celsius is the unit of temperature on the Celsius scale (originally known as the centigrade scale outside Sweden), one of two temperature scales used in the International System of Units (SI), the other being the Kelvin scale. The ...

(73.4-80.6 °F.

Spawning Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aquat ...

in captivity has not yet been reliably reported.

Sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most an ...

is slight, being determined mainly by a more rounded body shape in the females, and orange "cheeks", this refers to the operculum, in the males. The fish will, unlike most hypostomines, feed on flake from the water surface, turning upside-down to do so. It is also able to augment water-dissolved

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as ...

with atmospheric oxygen, but does not need to do so, having fully functional

gills A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

, so when this fish does gulp it is a useful warning that the

aeration Aeration (also called aerification or aeriation) is the process by which air is circulated through, mixed with or dissolved in a liquid or other substances that act as a fluid (such as soil). Aeration processes create additional surface area in ...

in the tank is low.

References

{{Taxonbar, from=Q3762647 Hypostominae Fish of South America Fish of the Amazon basin Taxa named by Pieter Bleeker Monotypic fish genera Monotypic freshwater fish genera Monotypic ray-finned fish genera Taxobox binomials not recognized by IUCN

Taxonomy

Appearance and anatomy

Ecology

In the aquarium

See also

References