Garra
Encyclopedia
Garra, the garras, are a genus
of ray-finned fish
in the family
Cyprinid
ae. These fish are one example of the "log suckers", sucker-mouthed
barbs and other cyprinids commonly kept in aquaria
to keep down algae
. The doctor fish
of Kangal
(Turkey
) also belongs into this genus.
The genus was established by Francis Buchanan-Hamilton
in 1822 as a subgenus
of Cyprinus
(which at that time was a "wastebin genus" for carp
-like cyprinids); he did not designate a type species
. But as no other garras except the newly-discovered G. lamta
were known to science in 1822, this was designated as the type species by Pieter Bleeker
in 1863. The garras and their closest relatives are sometimes placed in a subfamily Garrinae, but this seems hardly warranted. More often, this group is included in the Labeoninae
, or together with these in the Cyprininae. In the former case, the garras are members of the labeonine tribe
Garrini, in the latter they are in the subtribe Garraina of tribe Labeonini. The genus Discogobio
is a close relative.
s with a flat belly and a sucking mouth; their shape indicates that they are at least in tendency rheophilic. They are distinguished from other cyprinids by a combination of features: As in their closest relatives, their lower lip is expanded at its posterior rim to form a round or oval sucking pad, the vomero-palatine organ is much reduced or completely lost, the pectoral fins have at least the first two rays enlarged and usually unbranched, the supraethmoid is wider than long when seen from above, and the cleithrum
is narrow and elongated to the front.
From other Garrini (or Garraina), the genus Garra can be distinguished as follows: their pharyngeal teeth
are arranged in three rows (like 2,4,5–5,4,2), the dorsal fin
has 10-11 rays and starts slightly anterior to the pelvic fins, while the anal fin starts well behind the pelvic fins and has 8-9 rays. As far as is known, the diploid karyotype
of garras is 2n = 50.
Garras are not or barely noticeably sexually dimorphic and generally cryptic
ally coloured benthic freshwater
fish. They are omnivorous, eating alga, plankton
and small invertebrate
s that they suck off substrate
like rocks or logs. The food is scraped off with the sharp keratinized borders of the jaw
s, and ingested via suction
, created by contracting and relaxing the buccopharynx. As typical for Cypriniformes
, the garras lack a stomach
entirely, their oesophagus leading directly to the sphincter
of the intestine
. Different Garra species
eat animal and vegetable matter in different proportions, which can – as typical for vertebrate
s – usually be recognized by the length of their intestine compared to related species: more herbivorous species have a longer intestine. Indeed, intestinal length in this genus is remarkably constant within species and varies a lot between species, meaning that it is useful to distinguish species and that dietary shifts have played a significant role in the evolution
of garras.
When the females are ready to spawn
, they are markedly plum and swollen; the ripe roe
may fill almost four-fifths of their body cavity
. The testicle
s of reproductive males are large too. The average Garra egg is 1.77 mm in diameter
, and a clutch
contains several hundred eggs – up to a thousand or so in large females. The breeding behaviour is generally not well known and breeding is not often achieved in the aquarium
; presumably, like many of their relatives they migrate
upstream or (if they otherwise inhabit lakes) into the rivers to spawn.
of Garra were accepted in 2011. Some 2–3 new species are being described every year on average.
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 ray-finned fish
Actinopterygii
The Actinopterygii or ray-finned fishes constitute a class or sub-class of the bony fishes.The ray-finned fishes are so called because they possess lepidotrichia or "fin rays", their fins being webs of skin supported by bony or horny spines , as opposed to the fleshy, lobed fins that characterize...
in 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...
Cyprinid
Cyprinid
The family Cyprinidae, from the Ancient Greek kyprînos , consists of the carps, the true minnows, and their relatives . Commonly called the carp family or the minnow family, its members are also known as cyprinids...
ae. These fish are one example of the "log suckers", sucker-mouthed
Suckermouth
In fishes, a suckermouth is a ventrally-oriented mouth adapted for grazing on algae and small organisms that grow on submerged objects....
barbs and other cyprinids commonly kept in aquaria
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...
to keep down 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...
. The doctor fish
Doctor fish
Doctor fish is the name given to two species of fish: Garra rufa and Cyprinion macrostomus. Other nicknames include nibble fish, kangal fish, physio fish, and doctorfishen; in non-medical contexts, Garra rufa is called the reddish log sucker...
of Kangal
Kangal
Kangal is a town and a district of Sivas Province in Turkey. The mayor is Mehmet Öztürk .-See also:*Kangal Dog...
(Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
) also belongs into this genus.
The genus was established by Francis Buchanan-Hamilton
Francis Buchanan-Hamilton
Dr Francis Buchanan, later known as Francis Hamilton but often referred to as Francis Buchanan-Hamilton was a Scottish physician who made significant contributions as a geographer, zoologist, and botanist while living in India.The standard botanical author abbreviation Buch.-Ham. is applied to...
in 1822 as a subgenus
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
of Cyprinus
Cyprinus
Cyprinus is the genus of typical carps in family Cyprinidae. They are of East Asian origin and closely related to some more barb-like genera, such Cyclocheilichthys and the recently-established Barbonymus . The crucian carps of western Eurasia, which include the goldfish Cyprinus is the genus of...
(which at that time was a "wastebin genus" for carp
Carp
Carp are various species of oily freshwater fish of the family Cyprinidae, a very large group of fish native to Europe and Asia. The cypriniformes are traditionally grouped with the Characiformes, Siluriformes and Gymnotiformes to create the superorder Ostariophysi, since these groups have certain...
-like cyprinids); he did not designate a type species
Type 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...
. But as no other garras except the newly-discovered G. lamta
Garra lamta
Garra lamta is a species of ray-finned fish in the genus Garra....
were known to science in 1822, this was designated as the type species by Pieter Bleeker
Pieter Bleeker
Pieter Bleeker was a Dutch medical doctor and ichthyologist, famous for his work on the fishes of East Asia – Atlas Ichthyologique des Orientales Neerlandaises – which was published 1862–1877....
in 1863. The garras and their closest relatives are sometimes placed in a subfamily Garrinae, but this seems hardly warranted. More often, this group is included in the Labeoninae
Labeoninae
Labeoninae is a doubtfully distinct subfamily of ray-finned fishes in the family Cyprinidae of order Cypriniformes. They inhabit freshwater and are most abundant in the region around southern China. They are a generally very apomorphic group, perhaps the most "advanced" of the Cyprinidae...
, or together with these in the Cyprininae. In the former case, the garras are members of the labeonine 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...
Garrini, in the latter they are in the subtribe Garraina of tribe Labeonini. The genus Discogobio
Discogobio
Discogobio is a genus of cyprinid fish that are found in eastern Asia. So far the 16 species have only been identified from China and Vietnam wherein each species is an endemic to the country in which it is found.-Species:...
is a close relative.
Description and ecology
Garras are slim cyprinidCyprinid
The family Cyprinidae, from the Ancient Greek kyprînos , consists of the carps, the true minnows, and their relatives . Commonly called the carp family or the minnow family, its members are also known as cyprinids...
s with a flat belly and a sucking mouth; their shape indicates that they are at least in tendency rheophilic. They are distinguished from other cyprinids by a combination of features: As in their closest relatives, their lower lip is expanded at its posterior rim to form a round or oval sucking pad, the vomero-palatine organ is much reduced or completely lost, the pectoral fins have at least the first two rays enlarged and usually unbranched, the supraethmoid is wider than long when seen from above, and the cleithrum
Cleithrum
The cleithrum is a membrane bone which first appears as part of the skeleton in primitive bony fish, where it runs vertically along the scapula. Its name is derived from Greek κλειθρον = "key ", by analogy with "clavicle" from Latin clavicula = "little key".In modern fishes, the cleithrum is a...
is narrow and elongated to the front.
From other Garrini (or Garraina), the genus Garra can be distinguished as follows: their pharyngeal teeth
Pharyngeal teeth
Pharyngeal teeth are teeth in the pharyngeal arch of the throat of cyprinids, suckers, and a number of other fish species lacking teeth.Popular aquarium fish such as goldfish and loaches have these structures. Members of the Botia genus such as clown loaches are known to make distinctive clicking...
are arranged in three rows (like 2,4,5–5,4,2), the dorsal fin
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...
has 10-11 rays and starts slightly anterior to the pelvic fins, while the anal fin starts well behind the pelvic fins and has 8-9 rays. As far as is known, the diploid karyotype
Karyotype
A karyotype is the number and appearance of chromosomes in the nucleus of an eukaryotic cell. The term is also used for the complete set of chromosomes in a species, or an individual organism.p28...
of garras is 2n = 50.
Garras are not or barely noticeably sexually dimorphic and generally cryptic
Crypsis
In ecology, crypsis is the ability of an organism to avoid observation or detection by other organisms. It may be either a predation strategy or an antipredator adaptation, and methods include camouflage, nocturnality, subterranean lifestyle, transparency, and mimicry...
ally coloured benthic freshwater
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
fish. They are omnivorous, eating alga, plankton
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
and small invertebrate
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...
s that they suck off substrate
Substrate (marine biology)
Stream substrate is the material that rests at the bottom of a stream. There are several classification guides. One is:*Mud – silt and clay.*Sand – Particles between 0.06 and 2 mm in diameter.*Granule – Between 2 and 4 mm in diameter....
like rocks or logs. The food is scraped off with the sharp keratinized borders of the 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, and ingested via suction
Suction
Suction is the flow of a fluid into a partial vacuum, or region of low pressure. The pressure gradient between this region and the ambient pressure will propel matter toward the low pressure area. Suction is popularly thought of as an attractive effect, which is incorrect since vacuums do not...
, created by contracting and relaxing the buccopharynx. As typical for Cypriniformes
Cypriniformes
The Cypriniformes are an order of ray-finned fish, including the carps, minnows, loaches and relatives. This order contains 5-6 families, over 320 genera, and more than 3,250 species, with new species being described every few months or so, and new genera being recognized regularly...
, the garras lack a stomach
Stomach
The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
entirely, their oesophagus leading directly to the sphincter
Sphincter
A sphincter is an anatomical structure, or a circular muscle, that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning...
of the intestine
Intestine
In human anatomy, the intestine is the segment of the alimentary canal extending from the pyloric sphincter of the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...
. Different Garra 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...
eat animal and vegetable matter in different proportions, which can – as typical for vertebrate
Vertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
s – usually be recognized by the length of their intestine compared to related species: more herbivorous species have a longer intestine. Indeed, intestinal length in this genus is remarkably constant within species and varies a lot between species, meaning that it is useful to distinguish species and that dietary shifts have played a significant role in the evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
of garras.
When the females are ready to spawn
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...
, they are markedly plum and swollen; the ripe roe
Roe
Roe or hard roe is the fully ripe internal egg masses in the ovaries, or the released external egg masses of fish and certain marine animals, such as shrimp, scallop and sea urchins...
may fill almost four-fifths of their body cavity
Body cavity
By the broadest definition, a body cavity is any fluid-filled space in a multicellular organism. However, the term usually refers to the space located between an animal’s outer covering and the outer lining of the gut cavity, where internal organs develop...
. The testicle
Testicle
The testicle is the male gonad in animals. Like the ovaries to which they are homologous, testes are components of both the reproductive system and the endocrine system...
s of reproductive males are large too. The average Garra egg is 1.77 mm in diameter
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
, and a clutch
Clutch (eggs)
A clutch of eggs refers to all the eggs produced by birds or reptiles, often at a single time, particularly those laid in a nest.In birds, destruction of a clutch by predators, , results in double-clutching...
contains several hundred eggs – up to a thousand or so in large females. The breeding behaviour is generally not well known and breeding is not often achieved in the 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...
; presumably, like many of their relatives they migrate
Fish migration
Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres...
upstream or (if they otherwise inhabit lakes) into the rivers to spawn.
Species
About 100 speciesSpecies
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 Garra were accepted in 2011. Some 2–3 new species are being described every year on average.