Pterophyllum
Encyclopedia
Pterophyllum is a small genus
of freshwater
fish from the family
Cichlidae known to most aquarists as "Angelfish". All Pterophyllum species originate from the Amazon River
, Orinoco River and Essequibo River
basins in tropical South America. The three species of Pterophyllum are unusually shaped for cichlid
s being greatly laterally compressed, with round bodies and elongated triangular dorsal and anal fins. This body shape allows them to hide among roots and plants, often on a vertical surface. Naturally occurring angelfish are frequently striped longitudinally, colouration which provides additional camouflage
. Angelfish are ambush predators
and prey on small fish and macroinvertebrates
. All Pterophyllum species form monogamous
pairs. Eggs
are generally laid on a submerged log or a flattened leaf. As is the case for other cichlids, brood care is highly developed.
It was not until the late 1920s to early 1930s that the angelfish was bred in captivity in the United States.
In 1963 another species of Pterophyllum were discovered, P. leopoldi, this species was described by Gosse. In the beginning they were first described under another name, with P. leopoldi becoming the valid scientific name. Prior to that a species by the name of Pterophyllum altum had been discovered in 1906 by Pellegrin. There may still be undiscovered species in the Amazon River. New species of fish are discovered with increasing frequency, and, like P. scalare and leopoldi, the differences may be subtle. Scientific notations describe the P. leopoldi as having 29–35 scales in a lateral row and straight predorsal contour. Whereas, the P. scalare is described as having 35–45 scales in a lateral row and a notched predorsal contour. The leopoldi show the same coloration as scalare. Leopoldi can show a faint stripe between the eye stripe and the first complete body stripe and a third incomplete body stripe between the two main (complete) body stripes that extends three-fourths the length of the body. Whereas, the scalare's body does not show the stripe between the eye stipe and first complete body stripe at all, and the third stripe between the two main body stripes rarely extends downward more than a half inch, if even present. The leopoldi fry develop three to eight body stripes, with all but one to five fading away as they mature, whereas scalare only have two in true wild form throughout life.
Angelfish were bred in captivity for some 30 years prior to leopoldi being described; possibly longer outside the United States.
Pterophyllum altum, also referred to as the Altum Angelfish, Deep Angelfish, or Orinoco Angelfish, occurs strictly in the Orinoco River
Basin and the Upper Rio Negro watershed in Southern Venezuela
, Southeastern Colombia
and extreme Northern Brazil
. The species is the largest of the genus and specimens exceeding 50 cm in height (from tip of dorsal to tip of anal fin) have been reported in the wild; in aquariums, specimens are known to have grown to over 40 cm. Its natural base color is silver but with three brownish/red vertical stripes and red striations into the fins. The species may show red spotting and a blueish green dorsal overcast when mature and when aroused exhibits a black operculum spot. Characteristic of this species is an acute incision or notch above the nares (supraorbital indention). All true Orinoco Altum specimens show this trait, whereas commercial hybrids product of crosses to Pterophyllum scalare, that are occasionally performed by breeders to sell them as "Orinoco Altum", may not exhibit the trait or it may appear in a lesser degree. The true wildcaught Orinoco Altum is among the most challenging among tropical fish to breed in captivity. Most Altum Angels are more frequently found in the well oxygenated, extremely soft waters of Upper and Middle Orinoco tributaries
shed from the Guiana Shield Highlands, preferring a pH
range between 4.5 to 5.8. These are very transparent blackwaters with almost nil conductivity. Temperature range in these waters is between 78 and 84 °F (25.6 and 28.9 C). They are also found in the Atabapo River and Inirida River floodplain, down the Casiquiare
and Guainía floodplain where the Rio Negro is born, before entering Brazilian territory. Unlike P. scalare (mentioned above) which prefer to spawn on the submerged leaves of plants and trees in the flooded rainforest, P. altum prefers to spawn on submerged roots and tree branches in a moderate water current. This species is recommended for intermediate to advanced aquarists due to the detailed maintenance it requires for proper health. Pterophyllum altum is the national fish of Venezuela and an image of the fish appears on some currency bills of that country.
Pterophyllum leopoldi, also referred to as the teardrop angelfish, long-nosed angelfish, dwarf angelfish, or Roman-nosed angelfish, is a river dwelling angelfish species that originates from rivers in the Amazon River basin along the Solimões River
, Amazon River, and Rupununi River. It is distinguished from other members of the Pterophyllum genus by the absence of a pre-dorsal notch and by the presence of a black blotch at the dorsal insertion on the 4th vertical bar. The species was originally described as Plataxoides leopoldi in 1963 by J.P. Gosse, and is frequently misidentified as P. dumerilii when the species is imported in the aquarium trade. P. leopoldi is the smallest of the angelfish species and the most aggressive.
basin in Peru
, Colombia
, and Brazil
, particularly the Ucayali, Solimões and Amazon rivers, as well as the rivers of Amapá
in Brazil, the Oyapock River
in French Guiana
and the Essequibo River
in Guyana
. It is found in swamps or flooded grounds where vegetation is dense and the water is either clear or silty. Its native water conditions range from a pH of 6.0 to 8.0, a water hardness range of 5 - 13 dH, and water temperature ranging from 24 to 30 °C (75 to 86 °F
). It was originally described as Zeus scalaris in 1823, and has also been described be several different names, including Platax scalaris, Plataxoides dumerilii, Pterophillum eimekei, Pterophyllum dumerilii, and Pterophyllum eimekei.
Angelfish are one of the most commonly kept freshwater aquarium fish, as well as the most commonly kept cichlid. They are prized for their unique shape, color and behavior.
" applies. Aggressive fish should not be kept with angelfish because their flowing fins are vulnerable to fin nipping. Some smaller more aggressive fish may even nip at the fins of these fish.
Angelfish pairs form long-term relationships where each individual will protect the other from threats and potential suitors. Upon the death or removal of one of the mated pair, breeders have experienced both the total refusal of the remaining mate to pair up with any other angelfish and successful breeding with subsequent mates.
Depending upon aquarium conditions, P. scalare reaches sexual maturity at the age of six to twelve months or more. In situations where the eggs are removed from the aquarium immediately after spawning, the pair is capable of spawning every seven to ten days. Around the age of approximately three years, spawning frequency will decrease and eventually cease.
When the pair is ready to spawn, they will choose an appropriate medium upon which to lay the eggs and spend one to two days picking off detritus
and algae
from the surface. This medium may be a broad-leaf plant in the aquarium, a flat surface such as a piece of slate placed vertically in the aquarium, a length of pipe, or even the glass sides of the aquarium. The female will deposit a line of eggs on the spawning substrate, followed by the male who will fertilize the eggs. This process will repeat itself until there are a total of 100 to more than 1,200 eggs, depending on the size and health of the female fish. As both parents care for the offspring throughout development, the pair will take turns maintaining a high rate of water circulation around the eggs by swimming very close to the eggs and fanning the eggs with their pectoral fins. In a few days, the eggs hatch and the fry remain attached to the spawning substrate. During this period, the fry will not eat and will survive by consuming the remains of their yolk sacs. At one week, the fry will detach and become free-swimming. Successful parents will keep close watch on the eggs until they become free-swimming. At the free-swimming stage, the fry can be fed newly-hatched brine shrimp
(Artemia spp.) or microworms. It is generally accepted that brine shrimp
are the superior choice for fast growth rates of fry.
P. altum is notably difficult to breed in an aquarium environment.
s and plecos
all are compatible with angelfish, although some tetras and barbs will usually nip at their long fins.
. For the most part, the original crosses of wild angelfish were not recorded and confusion between the various species of Pterophyllum, especially P. scalare and P. leopoldi, is common. This makes the origins of "Domestic angelfish" unclear. Domestic strains are most likely a collection of genes resulting from more than one species of wild angelfish combined with the selection of mutation
s in domesticated lines over the last 60 or more years. The result of this is a domestic angelfish that is a true hybrid with little more than a superficial resemblance to wild Pterophyllum species. It would be inaccurate to say that they accurately represent any species of wild angelfish, although they most resemble P. scalare and are frequently referred to as such.
Domestic angelfish have been bred and crossbred for several decades. There are hundreds of mutations of little importance by themselves. Much of the research into the known genetics of P. scalare is the result of the research of Dr. Joanne Norton, who published a series of 18 articles in Freshwater and Marine Aquarium (FAMA) Magazine. Those articles are reprinted at http://theangelfishsociety.org/genetics.htm .
Silver (+/+)
Gold (g/g)
Zebra (Z/+ or Z/Z)
Black Lace (D/+) / Zebra Lace (D/+ - Z/+)
Smokey (Sm/+)
Chocolate (Sm/Sm)
Halfblack (h/h)
Sunset Blushing (g/g S/S)
Koi (Gm/Gm S/S) or (Gm/g S/S)
Leopard (Sm/Sm Z/Z) or (Sm/Sm Z/+)
Blue Blushing (S/S)
Silver Gold Marble (Gm/+)
Ghost (S/+)
Gold Marble (Gm/g or Gm/Gm)
Marble (M/+ or M/M or M/g or M/Gm)
Black Hybrid (D/g or D/Gm)
Pearlscale (p/p)
Black Ghost (D/+ - S/+)
Albino (a/a)
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 freshwater
Fresh Water
Fresh Water is the debut album by Australian rock and blues singer Alison McCallum, released in 1972. Rare for an Australian artist at the time, it came in a gatefold sleeve...
fish from the 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...
Cichlidae known to most aquarists as "Angelfish". All Pterophyllum species originate from the 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...
, Orinoco River and Essequibo River
Essequibo River
The Esequibo River is the largest river in Guyana, and the largest river between the Orinoco and Amazon. Rising in the Acarai Mountains near the Brazil-Guyana border, the Essequibo flows to the north for 1,010 km through forest and savanna into the Atlantic Ocean.-Geography:There are countless...
basins in tropical South America. The three species of Pterophyllum are unusually shaped for cichlid
Cichlid
Cichlids are fishes from the family Cichlidae in the order Perciformes. Cichlids are members of a group known as the Labroidei along with the wrasses , damselfish , and surfperches . This family is both large and diverse. At least 1,300 species have been scientifically described, making it one of...
s being greatly laterally compressed, with round bodies and elongated triangular dorsal and anal fins. This body shape allows them to hide among roots and plants, often on a vertical surface. Naturally occurring angelfish are frequently striped longitudinally, colouration which provides additional camouflage
Camouflage
Camouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...
. Angelfish are ambush predators
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
and prey on small fish and macroinvertebrates
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
. All Pterophyllum species form monogamous
Monogamy
Monogamy /Gr. μονός+γάμος - one+marriage/ a form of marriage in which an individual has only one spouse at any one time. In current usage monogamy often refers to having one sexual partner irrespective of marriage or reproduction...
pairs. Eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
are generally laid on a submerged log or a flattened leaf. As is the case for other cichlids, brood care is highly developed.
History
The freshwater angelfish was first talked about by Lichtenstein in 1824. Being scientifically named Pterophyllum scalare , the meaning of Pterophyllum is "winged leaf".It was not until the late 1920s to early 1930s that the angelfish was bred in captivity in the United States.
In 1963 another species of Pterophyllum were discovered, P. leopoldi, this species was described by Gosse. In the beginning they were first described under another name, with P. leopoldi becoming the valid scientific name. Prior to that a species by the name of Pterophyllum altum had been discovered in 1906 by Pellegrin. There may still be undiscovered species in the Amazon River. New species of fish are discovered with increasing frequency, and, like P. scalare and leopoldi, the differences may be subtle. Scientific notations describe the P. leopoldi as having 29–35 scales in a lateral row and straight predorsal contour. Whereas, the P. scalare is described as having 35–45 scales in a lateral row and a notched predorsal contour. The leopoldi show the same coloration as scalare. Leopoldi can show a faint stripe between the eye stripe and the first complete body stripe and a third incomplete body stripe between the two main (complete) body stripes that extends three-fourths the length of the body. Whereas, the scalare's body does not show the stripe between the eye stipe and first complete body stripe at all, and the third stripe between the two main body stripes rarely extends downward more than a half inch, if even present. The leopoldi fry develop three to eight body stripes, with all but one to five fading away as they mature, whereas scalare only have two in true wild form throughout life.
Angelfish were bred in captivity for some 30 years prior to leopoldi being described; possibly longer outside the United States.
P. altum
Orinoco
The Orinoco is one of the longest rivers in South America at . Its drainage basin, sometimes called the Orinoquia, covers , with 76.3% of it in Venezuela and the remainder in Colombia...
Basin and the Upper Rio Negro watershed in Southern 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...
, Southeastern Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
and extreme Northern 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...
. The species is the largest of the genus and specimens exceeding 50 cm in height (from tip of dorsal to tip of anal fin) have been reported in the wild; in aquariums, specimens are known to have grown to over 40 cm. Its natural base color is silver but with three brownish/red vertical stripes and red striations into the fins. The species may show red spotting and a blueish green dorsal overcast when mature and when aroused exhibits a black operculum spot. Characteristic of this species is an acute incision or notch above the nares (supraorbital indention). All true Orinoco Altum specimens show this trait, whereas commercial hybrids product of crosses to Pterophyllum scalare, that are occasionally performed by breeders to sell them as "Orinoco Altum", may not exhibit the trait or it may appear in a lesser degree. The true wildcaught Orinoco Altum is among the most challenging among tropical fish to breed in captivity. Most Altum Angels are more frequently found in the well oxygenated, extremely soft waters of Upper and Middle Orinoco tributaries
Tributary
A tributary or affluent is a stream or river that flows into a main stem river or a lake. A tributary does not flow directly into a sea or ocean...
shed from the Guiana Shield Highlands, preferring a 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...
range between 4.5 to 5.8. These are very transparent blackwaters with almost nil conductivity. Temperature range in these waters is between 78 and 84 °F (25.6 and 28.9 C). They are also found in the Atabapo River and Inirida River floodplain, down the Casiquiare
Casiquiare canal
The Casiquiare river is a distributary of the upper Orinoco flowing southward into the Rio Negro, in Venezuela, South America. As such, it forms a unique natural canal between the Orinoco and Amazon river systems. It is the largest river on the planet that links two major river systems, a...
and Guainía floodplain where the Rio Negro is born, before entering Brazilian territory. Unlike P. scalare (mentioned above) which prefer to spawn on the submerged leaves of plants and trees in the flooded rainforest, P. altum prefers to spawn on submerged roots and tree branches in a moderate water current. This species is recommended for intermediate to advanced aquarists due to the detailed maintenance it requires for proper health. Pterophyllum altum is the national fish of Venezuela and an image of the fish appears on some currency bills of that country.
P. leopoldi
Solimões
Solimões is the name often given to early stretches of the Amazon River from the border of Brazil and Peru to its confluence with the Rio Negro.Further upstream from the border, the name of the river seems to depend on the speaker...
, Amazon River, and Rupununi River. It is distinguished from other members of the Pterophyllum genus by the absence of a pre-dorsal notch and by the presence of a black blotch at the dorsal insertion on the 4th vertical bar. The species was originally described as Plataxoides leopoldi in 1963 by J.P. Gosse, and is frequently misidentified as P. dumerilii when the species is imported in the aquarium trade. P. leopoldi is the smallest of the angelfish species and the most aggressive.
P. scalare
Pterophyllum scalare, the species most commonly referred to as angelfish or freshwater angelfish, is the most common species of Pterophyllum held in captivity. Its natural habitat Amazon RiverAmazon 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 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....
, Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
, 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...
, particularly the Ucayali, Solimões and Amazon rivers, as well as the rivers of Amapá
Amapá
Amapá is one of the states of Brazil, located in the extreme north, bordering French Guiana and Suriname to the north. To the east is the Atlantic Ocean, and to the south and west is the Brazilian state of Pará. Perhaps one of the main features of the state is the River Oiapoque, as it was once...
in Brazil, the Oyapock River
Oyapock River
The Oyapock or Oiapoque River is a 370-km long river in South America that forms most of the border between French Guiana and the Brazilian state of Amapá...
in French Guiana
French Guiana
French Guiana is an overseas region of France, consisting of a single overseas department located on the northern Atlantic coast of South America. It has borders with two nations, Brazil to the east and south, and Suriname to the west...
and the Essequibo River
Essequibo River
The Esequibo River is the largest river in Guyana, and the largest river between the Orinoco and Amazon. Rising in the Acarai Mountains near the Brazil-Guyana border, the Essequibo flows to the north for 1,010 km through forest and savanna into the Atlantic Ocean.-Geography:There are countless...
in 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...
. It is found in swamps or flooded grounds where vegetation is dense and the water is either clear or silty. Its native water conditions range from a pH of 6.0 to 8.0, a water hardness range of 5 - 13 dH, and water temperature ranging from 24 to 30 °C (75 to 86 °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...
). It was originally described as Zeus scalaris in 1823, and has also been described be several different names, including Platax scalaris, Plataxoides dumerilii, Pterophillum eimekei, Pterophyllum dumerilii, and Pterophyllum eimekei.
Angelfish in the fishkeeping hobby
Species
The most commonly kept species in the aquarium is Pterophyllum scalare. Most of the individuals the aquarium trade are captive-bred. Sometimes, Pterophyllum altum is available. Captive bred P. altum is available but occasionally. Pterophyllum leopoldi is the hardest to find in the trade.Care
Angelfish are kept in a warm aquarium, ideally around 80 °F (26.7 °C). They will do best if fed a mixture of flake, frozen and live food. Care should be taken to not overfeed, they will continue to eat even what they do not need to. This will lead to a buildup of fats resulting in inactivity and early death. Angelfish will do best if kept in an acidic environment, pH should be below 7.5 (note: 7.5 is still slightly alkaline – acidic is defined as below 7.0). All angelfish will prefer water with a pH of at most 7.0. Though most Pterophyllum scalare will thrive in a wide range of pH values. Even though angelfish are a member of the Cichlid family they are generally peaceful, however; the general rule "big fish eat little fishPredation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
" applies. Aggressive fish should not be kept with angelfish because their flowing fins are vulnerable to fin nipping. Some smaller more aggressive fish may even nip at the fins of these fish.
Breeding
P. scalare is relatively easy to breed in the aquarium, although one of the results of generations of inbreeding is that many breeds have almost completely lost their rearing instincts resulting in the tendency of the parents to eat their young. In addition, it is very difficult to accurately identify the gender of any individual until they are nearly ready to breed.Angelfish pairs form long-term relationships where each individual will protect the other from threats and potential suitors. Upon the death or removal of one of the mated pair, breeders have experienced both the total refusal of the remaining mate to pair up with any other angelfish and successful breeding with subsequent mates.
Depending upon aquarium conditions, P. scalare reaches sexual maturity at the age of six to twelve months or more. In situations where the eggs are removed from the aquarium immediately after spawning, the pair is capable of spawning every seven to ten days. Around the age of approximately three years, spawning frequency will decrease and eventually cease.
When the pair is ready to spawn, they will choose an appropriate medium upon which to lay the eggs and spend one to two days picking off 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 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...
from the surface. This medium may be a broad-leaf plant in the aquarium, a flat surface such as a piece of slate placed vertically in the aquarium, a length of pipe, or even the glass sides of the aquarium. The female will deposit a line of eggs on the spawning substrate, followed by the male who will fertilize the eggs. This process will repeat itself until there are a total of 100 to more than 1,200 eggs, depending on the size and health of the female fish. As both parents care for the offspring throughout development, the pair will take turns maintaining a high rate of water circulation around the eggs by swimming very close to the eggs and fanning the eggs with their pectoral fins. In a few days, the eggs hatch and the fry remain attached to the spawning substrate. During this period, the fry will not eat and will survive by consuming the remains of their yolk sacs. At one week, the fry will detach and become free-swimming. Successful parents will keep close watch on the eggs until they become free-swimming. At the free-swimming stage, the fry can be fed newly-hatched brine shrimp
Brine shrimp
Artemia is a genus of aquatic crustaceans known as brine shrimp. Artemia, the only genus in the family Artemiidae, has changed little externally since the Triassic period...
(Artemia spp.) or microworms. It is generally accepted that brine shrimp
Brine shrimp
Artemia is a genus of aquatic crustaceans known as brine shrimp. Artemia, the only genus in the family Artemiidae, has changed little externally since the Triassic period...
are the superior choice for fast growth rates of fry.
P. altum is notably difficult to breed in an aquarium environment.
Compatibility with other fish
In pet stores the freshwater angelfish is typically placed in the semi-aggressive category, but that might prove false with some fish. For example, tetraTetra
thumb|right|250px|Pristella tetra — [[Pristella maxillaris]].thumb|right|250px|Golden Pristella tetra, a [[morph |morph]] of [[Pristella maxillaris]].thumb|right|250px|[[Silvertip tetra]] — Hasemania nana....
s and plecos
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...
all are compatible with angelfish, although some tetras and barbs will usually nip at their long fins.
Strains of Angelfish
Most strains of angelfish available in the fishkeeping hobby are the result of many decades of selective breedingSelective breeding
Selective breeding is the process of breeding plants and animals for particular genetic traits. Typically, strains that are selectively bred are domesticated, and the breeding is sometimes done by a professional breeder. Bred animals are known as breeds, while bred plants are known as varieties,...
. For the most part, the original crosses of wild angelfish were not recorded and confusion between the various species of Pterophyllum, especially P. scalare and P. leopoldi, is common. This makes the origins of "Domestic angelfish" unclear. Domestic strains are most likely a collection of genes resulting from more than one species of wild angelfish combined with the selection of mutation
Mutation
In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...
s in domesticated lines over the last 60 or more years. The result of this is a domestic angelfish that is a true hybrid with little more than a superficial resemblance to wild Pterophyllum species. It would be inaccurate to say that they accurately represent any species of wild angelfish, although they most resemble P. scalare and are frequently referred to as such.
Domestic angelfish have been bred and crossbred for several decades. There are hundreds of mutations of little importance by themselves. Much of the research into the known genetics of P. scalare is the result of the research of Dr. Joanne Norton, who published a series of 18 articles in Freshwater and Marine Aquarium (FAMA) Magazine. Those articles are reprinted at http://theangelfishsociety.org/genetics.htm .
Silver (+/+)
- The silver angelfish most commonly resembles the wild form of angelfish, and is also referred to as "wild-type". It is not, however, caught in the wild and is considered domestic. The fish has a silver body with red eyes and three vertical black stripes that can fade or darken depending on the mood of the fish.
Gold (g/g)
- The genetic trait for the gold angelfish is recessive, and causes a light golden body with a darker yellow or orange color on the crown of the fish. It does not have the vertical black stripes or the red eye seen in the wild angelfish.
Zebra (Z/+ or Z/Z)
- The zebra phenotype results in 4 to 6 vertical stripes on the fish that in other ways resembles a silver angelfish. It is a dominant mutation that exists at the same locus as the stripeless gene.
Black Lace (D/+) / Zebra Lace (D/+ - Z/+)
- A Silver or Zebra with one copy of the Dark gene. This results in very attractive lacing in the fins. Considered by some to the most attractive of all angelfish varieties.
Smokey (Sm/+)
- A variety with a dark brownish grey back half and dark dorsal and anal fins.
Chocolate (Sm/Sm)
- Homozygous for Smokey with more of the dark pattern. Sometimes only the head is silver.
- Silver with a black rear portion. Halfblack can express along with some other color genes, but not all. The pattern may not develop or express if the fish are in stressful conditions.
- The Sunset Blushing has two doses of gold and two doses of Stripeless. The upper half of the fish exhibits orange on the good ones. The body is mostly white in color, fins are clear. The amount of orange showing on the fish can vary. On some the body is a pinkish or tangerine color. The term blushing comes from the clear gill plates found on juveniles. You can see the pinkish gill underneath.
- The Koi has a double or single dose of Gold Marble with a double dose of Stripeless. They express a variable amount of orange that varies with stress levels. The black marbling varies from 5%-40% coverage.
Leopard (Sm/Sm Z/Z) or (Sm/Sm Z/+)
- The leopard is a very popular fish when young, having spots over most of their body. Most of these spots grow closer together as an adult so it looks like a chocolate with dots on it. (Smokey x Zebra)
Blue Blushing (S/S)
- This is a wild-type angelfish that has two Stripeless genes. The body is actually grey with a bluish tint under the right light spectrum. An iridescent pigment develops as they age. This iridescence usually appears blue under most lighting.
Silver Gold Marble (Gm/+)
- A Silver angel with a single Gold Marble gene. This is a co-dominant expression of Silver and Gold Marble, so you see traits of both.
Ghost (S/+)
- A fish that is heterozygous for Stripeless. This results in a mostly silver fish with just a stripe through the eye and tail. Sometimes portions of the body stripes will express.
Gold Marble (Gm/g or Gm/Gm)
- A gold angel with black marbling. Depending on whether the Gold Marble is single or double dose, the marbling will range from 5% to 40% coverage.
- Marble expresses with much more black pattern than Gold Marble does. The marbling varies from 50% to 95%.
Black Hybrid (D/g or D/Gm)
- Cross a black with a gold, and you get black hybrids. A very vigorous black, that may look brassy when young. Does not breed true.
- Pearlscale is a scale mutation. The "pearlscale" angelfish is also called the "diamond" angelfish in some regions due to the gem-like iridiscence on its scales. The scale have a wrinkled, wavy look that reflect light to create a sparkling effect. Pearl develops slowly, starting at around 9 weeks of age. In can be inhibited by stressful conditions. It is recessive, requiring both parents to contain the allele. It looks best on light colored fish like Gold, Gold Marble, Albino, Silver and Zebra. It is difficult to see on dark fish and blushing angelfish.
Black Ghost (D/+ - S/+)
- Same description as a Ghost, with a darker appearance due to the Dark gene. Very similar to a Black Lace without complete stripes. Ghosts generally have more iridescence than non-ghosts.
Albino (a/a)
- Albino removes dark pigments in most varieties. Some, like Albino Marble will still have a little black remaining on a percentage of the fish. The eye pupils are pink as in all albino animals. The surrounding iris can be red or yellow depending on the variety of Albino.