Ancistrus
Encyclopedia
Ancistrus is a genus of freshwater fish in the family
Loricariidae
of order Siluriformes. Fish of this genus are commonly known as the bushynose or bristlenose plecos.
is Ancistrus cirrhosus. This genus is the largest genus within the tribe
Ancistrini
.
The name ancistrus derives from the Greek 'agkistron' meaning hook - a reference to the form of the cheek odontodes. The genera Pristiancistrus, Thysanocara and Xenocara are now synonyms of Ancistrus.
Ancistrus species show all the typical features of the Loricariidae. This includes a body covered in bony plates and a ventral suckermouth
. The feature most commonly associated with the genus are the fleshy tentacles found on the head in adult males; females may possess tentacles along the snout margin but they are smaller and they lack tentacles on the head. Tentacules, tentacles directly associated with odontode
s, develop on the pectoral fin spine of the males of some species. Males also have evertible cheek odontodes which are less developed or absent in females. They also lack odontodes along the snout. In comparison with a typical pleco, a bristlenose is typically shorter (15 cm or less), more flattened and fatter with a comparatively wider head. Colouration is typically mottled brown, grey or black. Small white or yellow spots are common. Unlike other plecos which commonly grow to over a foot long, the bristlenose pleco may only grow to half the size, this makes it a suitable species of pleco for the smaller tank.
in South America. There are also some species, A. cryptophthalmus and A. formoso, that live in caves
.
and aufwuchs
. Bristlenoses do not school but hide when not feeding, juveniles however are typically found in brightly lit shallows at the water margin making them susceptible to predation by birds.
Ancistrus species have the capability of obtaining oxygen through their modified stomach. This allows them to survive in conditions with low oxygen levels
.
Breeding takes place in hollows, caves and mud holes in banks. Males may clean the inside of the cavity with their suckermouth before allowing the female to approach and inspect the nest. Courtship
includes expanding the dorsal and caudal fins and attempts by the male to escort the female to the nest. While the female inspects the nest, the male keeps close contact. The female may lay 20-200 adhesive eggs, usually to the ceiling of the cavity.
The female plays no role in parental care; the male takes care of its young. Males will clean the eggs and the cavity with its fins and mouth. Males inspect eggs to remove diseased or infertile eggs, and aerates the clutch by fanning them with its pectoral and pelvic fins. During this time, a male usually will not leave the cavity to feed, or will leave only occasionally and quickly return. The eggs hatch in 4–10 days over a period of 2–6 hours; the male guards the eggs for 7–10 days after hatching. The fry remain in the cave, attaching to the walls and ceiling with their mouths, absorbing their yolk sac in 2–4 days and becoming free swimming.
Males of these species are competitive and territorial. Males display to each other by positioning themselves parallel to each other, head to tail, with dorsal and caudal fins erect and cheek odontode spines everted. If this escalates to combat, the males will circle each other and direct attacks at the head. If an intruding male manages to evict another male from the nest, it may cannibalize the other male's young.
A male bristlenose may guard several clutches of eggs simultaneously. Females prefer males that are already protecting eggs and may prefer males that are protecting larvae; it has been suggested that the tentacles may act as a fry mimic
to attract females, which would allow males without eggs in their nest to compete with males guarding eggs. Several clutches in various states of development from eggs to free-swimming larvae can be found in one nest.
Historically commonly available species of Ancistrus were Ancistrus cirrhosus and Ancistrus temminckii, other species are now available though exact identification is difficult.
Feeding is easy, bristlenoses will graze on algae and other surface growing organisms as well as eating algae wafers or tablets, flake food, squash, spinach, cucumber, zucchini, green beans and peas however they have been known to accept frozen bloodworms as part of their diet. Aquarium specimens may starve for lack of algae or other plant matter; algae wafers or other low-protein foods are recommended. Keepers should watch for the abdomen to take on a sunken appearance, indicating insufficient nutrition.
Like other plecs benefit from the addition of bogwood, which they will rasp at and use as a hiding place - in the absence of other plant matter (sources of fibre) wood may be essential to the survival of these fish in the aquarium as it helps digestion of typically high protein fish food.
Sexing is very easy as the female will occasionally have bristles around the edge of the chin and the male will have them up the center of the head
Breeding is also possible: Males attract females to small cave or hollow, then guard eggs after fertilization through hatching (4–8 days) until fry are free swimming (4–6 days after hatching); the aquarist need only supply a suitable cave, food, and one of each sex.
Caution should be taken with the spines (odontodes) - although the risk of personal injury is small with this genus the hooked nature of the odontodes means that a bristlenose may become trapped in non-natural material such as sponge filters and netting.
and may continue to be so identified (especially outside academic circles).
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...
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...
of order Siluriformes. Fish of this genus are commonly known as the bushynose or bristlenose plecos.
Taxonomy
The type speciesType species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
is Ancistrus cirrhosus. This genus is the largest genus within the tribe
Tribe (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...
Ancistrini
Ancistrini
Ancistrini is a tribe of catfishes of the family Loricariidae.-Taxonomy:Ancistrini has previously been considered a loricariid subfamily. However, it was realized that the subfamily Hypostominae would be paraphyletic if Ancistrinae continued to be recognized...
.
The name ancistrus derives from the Greek 'agkistron' meaning hook - a reference to the form of the cheek odontodes. The genera Pristiancistrus, Thysanocara and Xenocara are now synonyms of Ancistrus.
Appearance and anatomy
Suckermouth
In fishes, a suckermouth is a ventrally-oriented mouth adapted for grazing on algae and small organisms that grow on submerged objects....
. The feature most commonly associated with the genus are the fleshy tentacles found on the head in adult males; females may possess tentacles along the snout margin but they are smaller and they lack tentacles on the head. Tentacules, tentacles directly associated with 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, develop on the pectoral fin spine of the males of some species. Males also have evertible cheek odontodes which are less developed or absent in females. They also lack odontodes along the snout. In comparison with a typical pleco, a bristlenose is typically shorter (15 cm or less), more flattened and fatter with a comparatively wider head. Colouration is typically mottled brown, grey or black. Small white or yellow spots are common. Unlike other plecos which commonly grow to over a foot long, the bristlenose pleco may only grow to half the size, this makes it a suitable species of pleco for the smaller tank.
Distribution and habitat
The Ancistrus is one of the widest ranging genera of the family, and representatives are found throughout the range of Loricariidae. They are found throughout rivers and floodplain areas of the 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...
in South America. There are also some species, A. cryptophthalmus and A. formoso, that live in caves
Troglobite
Troglobites are small cave-dwelling animals that have adapted to their dark surroundings. Troglobite species include spiders, insects, fish and others. They live permanently underground and cannot survive outside the cave environment. Troglobite adaptations and characteristics include a heightened...
.
Ecology
The diet of this genus is typical for a Loricariid - algaeAlgae
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...
and 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-"...
. Bristlenoses do not school but hide when not feeding, juveniles however are typically found in brightly lit shallows at the water margin making them susceptible to predation by birds.
Ancistrus species have the capability of obtaining oxygen through their modified stomach. This allows them to survive in conditions with low oxygen levels
Hypoxia (environmental)
Hypoxia, or oxygen depletion, is a phenomenon that occurs in aquatic environments as dissolved oxygen becomes reduced in concentration to a point where it becomes detrimental to aquatic organisms living in the system...
.
Breeding takes place in hollows, caves and mud holes in banks. Males may clean the inside of the cavity with their suckermouth before allowing the female to approach and inspect the nest. Courtship
Courtship
Courtship is the period in a couple's relationship which precedes their engagement and marriage, or establishment of an agreed relationship of a more enduring kind. In courtship, a couple get to know each other and decide if there will be an engagement or other such agreement...
includes expanding the dorsal and caudal fins and attempts by the male to escort the female to the nest. While the female inspects the nest, the male keeps close contact. The female may lay 20-200 adhesive eggs, usually to the ceiling of the cavity.
The female plays no role in parental care; the male takes care of its young. Males will clean the eggs and the cavity with its fins and mouth. Males inspect eggs to remove diseased or infertile eggs, and aerates the clutch by fanning them with its pectoral and pelvic fins. During this time, a male usually will not leave the cavity to feed, or will leave only occasionally and quickly return. The eggs hatch in 4–10 days over a period of 2–6 hours; the male guards the eggs for 7–10 days after hatching. The fry remain in the cave, attaching to the walls and ceiling with their mouths, absorbing their yolk sac in 2–4 days and becoming free swimming.
Males of these species are competitive and territorial. Males display to each other by positioning themselves parallel to each other, head to tail, with dorsal and caudal fins erect and cheek odontode spines everted. If this escalates to combat, the males will circle each other and direct attacks at the head. If an intruding male manages to evict another male from the nest, it may cannibalize the other male's young.
A male bristlenose may guard several clutches of eggs simultaneously. Females prefer males that are already protecting eggs and may prefer males that are protecting larvae; it has been suggested that the tentacles may act as a fry mimic
Mimic
In evolutionary biology, mimicry is the similarity of one species to another which protects one or both. This similarity can be in appearance, behaviour, sound, scent and even location, with the mimics found in similar places to their models....
to attract females, which would allow males without eggs in their nest to compete with males guarding eggs. Several clutches in various states of development from eggs to free-swimming larvae can be found in one nest.
In the aquarium
These fish are often kept by aquarists as they are dutiful algae-eaters and smaller in adult size than the common plecos usually seen in petshops. Size is up to 15 cm (male), 12 cm (female), recommended temperature 23-27 degrees Celsius, lifespan up to 12 years. They are hardy animals, tolerant to a wide range of water conditions, breeding easily in captivity, compatible with most other freshwater fish, though typically mottled brown in colour, other species are more exotic - spots of bright yellow on a dark background being a common patternation, albino variants are also common. It is thought that the eggs of the bristle-nosed pleco are light sensitive; albino fish may be the result of exposure to excessive light.Historically commonly available species of Ancistrus were Ancistrus cirrhosus and Ancistrus temminckii, other species are now available though exact identification is difficult.
Feeding is easy, bristlenoses will graze on algae and other surface growing organisms as well as eating algae wafers or tablets, flake food, squash, spinach, cucumber, zucchini, green beans and peas however they have been known to accept frozen bloodworms as part of their diet. Aquarium specimens may starve for lack of algae or other plant matter; algae wafers or other low-protein foods are recommended. Keepers should watch for the abdomen to take on a sunken appearance, indicating insufficient nutrition.
Like other plecs benefit from the addition of bogwood, which they will rasp at and use as a hiding place - in the absence of other plant matter (sources of fibre) wood may be essential to the survival of these fish in the aquarium as it helps digestion of typically high protein fish food.
Sexing is very easy as the female will occasionally have bristles around the edge of the chin and the male will have them up the center of the head
Breeding is also possible: Males attract females to small cave or hollow, then guard eggs after fertilization through hatching (4–8 days) until fry are free swimming (4–6 days after hatching); the aquarist need only supply a suitable cave, food, and one of each sex.
Caution should be taken with the spines (odontodes) - although the risk of personal injury is small with this genus the hooked nature of the odontodes means that a bristlenose may become trapped in non-natural material such as sponge filters and netting.
Species
The genus Ancistrus includes at least 59 named species. Unnamed Loricarrids are typically identified by an L-numberL-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 ....
and may continue to be so identified (especially outside academic circles).
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See also
- List of freshwater aquarium fish species
- XenocaraXenocaraXenocara is the OpenBSD build infrastructure for the project's customised X.Org 7.4. Until release 6.9, X.Org used imake but recent modularised versions have switched to GNU autotools. Xenocara uses BSD make and is designed to ease building and maintenance of modularised X.Org within the OpenBSD...
, a computer infrastructure in OpenBSDOpenBSDOpenBSD is a Unix-like computer operating system descended from Berkeley Software Distribution , a Unix derivative developed at the University of California, Berkeley. It was forked from NetBSD by project leader Theo de Raadt in late 1995...
that was named after the genus of fish
External links
- Planetcatfish.com - Thumbnails of Ancistrus species
- ITIS Listing for Ancistrus
- http://www.bettatrading.com.au/Bristlenose-Catfish-Fact-Sheet.php - Bristlenose Catfish Fact Sheet.
- How to Keep Bristlenose Plecostomids
- Ancistrinae Internet Lecture by Ingo Seidel (translated from the German) Detailed article on the tribe Ancistrini containing this genus with relevance to fishkeeping and breeding.