Pseudorinelepis
Encyclopedia
Pseudorinelepis genibarbis is a species
of the Hypostominae
subfamily of the Loricariidae
catfish
family
. P. genibarbis is distributed throughout the Upper Amazon River
basin.
Rhinelepini
, one of the tribes of Hypostominae
.
Canthopomus and Monistiancistrus are synonym
s of the genus Pseudorinelepis. Previously, Pseudorinelepis was a genus
of four species
, but now the other three species are synonymous with P. genibarbis.
s (14 in
) 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 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
, 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
s on the cheek that are denser and numerous than in females. It has been suggested that breeding males may also have orange on the cheeks and dorsal
and caudal fin spines, although this may be restricted to fish from the Branco River
.
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.
system in Peru
and Brazil
which has started since the 1990s to be offered quite regularly as an aquarium
fish
under the name "Pineapple Pleco". The term "pleco" here is of course a popular generalisation, as taxonomy
has never placed this fish in the former genus Plecostomus
. The armour is also pleasantly spiked along the sides of the fish, which causes the pineapple
resemblance celebrated in the commercial name of the species.
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
range may fluctuate gently between 23-27 °C
(73.4-80.6 °F
.
Spawning
in captivity
has not yet been reliably reported. Sexual dimorphism
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
with atmospheric oxygen, but does not need to do so, having fully functional gills, so when this fish does gulp it is a useful warning that the aeration
in the tank is low.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of the Hypostominae
Hypostominae
Hypostominae is a subfamily of catfishes of the family Loricariidae.Studies conducted with representatives of some genera of Hypostominae showed that within thisgroup, the diploid number ranges from 2n = 52 to 2n = 80...
subfamily of the Loricariidae
Loricariidae
Loricariidae is the largest family of catfish , with almost 700 species and new species being described each year. Loricariids originate from fresh water habitats of Costa Rica, Panama, and tropical and subtropical South America. These fish are noted for the bony plates covering their bodies and...
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...
family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
. P. genibarbis is distributed throughout the Upper Amazon River
Amazon River
The Amazon of South America is the second longest river in the world and by far the largest by waterflow with an average discharge greater than the next seven largest rivers combined...
basin.
Taxonomy
Pseudorinelepis is one of three genera contained in the tribeTribe (biology)
In biology, a tribe is a taxonomic rank between family and genus. It is sometimes subdivided into subtribes.Some examples include the tribes: Canini, Acalypheae, Hominini, Bombini, and Antidesmeae.-See also:* Biological classification* Rank...
Rhinelepini
Rhinelepini
Rhinelepini is a tribe of armored suckermouth catfish family within the Hypostominae subfamily.-Taxonomy:This tribe is a well diagnosed monophyletic group currently containing three genera: Pogonopoma, Pseudorinelepis, and Rhinelepis. When the tribe was first described, Pogonopomoides was a valid...
, one of the tribes of Hypostominae
Hypostominae
Hypostominae is a subfamily of catfishes of the family Loricariidae.Studies conducted with representatives of some genera of Hypostominae showed that within thisgroup, the diploid number ranges from 2n = 52 to 2n = 80...
.
Canthopomus and Monistiancistrus are synonym
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
s of the genus Pseudorinelepis. Previously, Pseudorinelepis was 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 four species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
, but now the other three species are synonymous with P. genibarbis.
Appearance and anatomy
P. genibarbis reaches a length of about 35 centimetreCentimetre
A centimetre is a unit of length in the metric system, equal to one hundredth of a metre, which is the SI base unit of length. Centi is the SI prefix for a factor of . Hence a centimetre can be written as or — meaning or respectively...
s (14 in
Inch
An inch is the name of a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot...
) SL
Fish measurement
Fish measurement refers to the measuring of the length of individual fish and of various parts of their anatomy. These data are used in many areas of ichthyology, including taxonomy and fisheries biology.-Overall length:...
. 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 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
Iquitos
Iquitos is the largest city in the Peruvian rainforest, with a population of 370,962. It is the capital of Loreto Region and Maynas Province.Located on the Amazon River, it is only above sea level, although it is more than from the mouth of the Amazon at Belém on the Atlantic Ocean...
, Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
, 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
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 cheek that are denser and numerous than in females. It has been suggested that breeding males may also have orange on the cheeks and dorsal
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
and caudal fin spines, although this may be restricted to fish from the Branco River
Branco River
The Rio Branco is the principal affluent of the Rio Negro from the north; it is enriched by many streams from the sierras which separate Venezuela and Guyana from Brazil. Its two upper main tributaries are the Urariquira and the Takutu...
.
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 (pHPH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
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
Buoyancy
In physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...
and swim in the water column.
In the aquarium
It is an armoured catfish from the upper AmazonAmazon 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...
system in Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
and 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...
which has started since the 1990s to be offered quite regularly as an 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
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate 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...
under the name "Pineapple Pleco". The term "pleco" here is of course a popular generalisation, as taxonomy
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
has never placed this fish in the former genus Plecostomus
Plecostomus
Hypostomus plecostomus is the scientific name for a type of freshwater tropical Central and South American fish belonging to the family Loricariidae. They are large algae eaters, and to differentiate them from small algae eaters, they are often referred to as plecostomus, often abbreviated as...
. The armour is also pleasantly spiked along the sides of the fish, which causes the pineapple
Pineapple
Pineapple is the common name for a tropical plant and its edible fruit, which is actually a multiple fruit consisting of coalesced berries. It was given the name pineapple due to its resemblance to a pine cone. The pineapple is by far the most economically important plant in the Bromeliaceae...
resemblance celebrated in the commercial name of the species.
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
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...
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
Substrate (aquarium)
The substrate of an aquarium refers to the material used on the tank bottom. It can affect water chemistry, filtration, and the well-being of the aquarium's inhabitants, and is also an important part of the aquarium's aesthetic appeal...
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
Chameleon
Chameleons are a distinctive and highly specialized clade of lizards. They are distinguished by their parrot-like zygodactylous feet, their separately mobile and stereoscopic eyes, their very long, highly modified, and rapidly extrudable tongues, their swaying gait, the possession by many of a...
" 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
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
values of up to 7.5 are acceptable, and the temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
range may fluctuate gently between 23-27 °C
Celsius
Celsius is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death...
(73.4-80.6 °F
Fahrenheit
Fahrenheit is the temperature scale proposed in 1724 by, and named after, the German physicist Daniel Gabriel Fahrenheit . Within this scale, the freezing of water into ice is defined at 32 degrees, while the boiling point of water is defined to be 212 degrees...
.
Spawning
Spawn (biology)
Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning...
in captivity
Captivity (animal)
Animals that live under human care are in captivity. Captivity can be used as a generalizing term to describe the keeping of either domesticated animals or wild animals. This may include for example farms, private homes and zoos...
has not yet been reliably reported. Sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
is slight, being determined mainly by a more rounded body shape in the females, and orange "cheeks", this refers to the operculum
Operculum (fish)
The operculum of a bony fish is the hard bony flap covering and protecting the gills. In most fish, the rear edge of the operculum roughly marks the division between the head and the body....
, in the males.
The fish will, unlike most hypostomines, feed on flake from the water surface
Surface
In mathematics, specifically in topology, a surface is a two-dimensional topological manifold. The most familiar examples are those that arise as the boundaries of solid objects in ordinary three-dimensional Euclidean space R3 — for example, the surface of a ball...
, turning upside-down to do so. It is also able to augment water-dissolved oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
with atmospheric oxygen, but does not need to do so, having fully functional gills, so when this fish does gulp it is a useful warning that the aeration
Aeration
Aeration is the process by which air is circulated through, mixed with or dissolved in a liquid or substance.-Aeration of liquids:-Methods:Aeration of liquids is achieved by:...
in the tank is low.