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. They are most diverse in southeastern Asia, but are entirely absent from Australia and South America.
Their closest living relatives are the Characiformes (characins and allies), the Gymnotiformes (electric eel and American knifefishes) and the Siluriformes (catfishes).
Description
Like other orders of the
Ostariophysi, the cypriniformes possess a
Weberian apparatus. However, they differ from most of their relatives in having only a
dorsal fin on their back; most other Ostariophysi have a small fleshy
adipose fin behind the dorsal fin. Further differences are the Cypriniformes'
kinethmoid and the lack of teeth in the mouth. Instead, they have
convergent structures called
pharyngeal teeth in the throat. While other groups of fish, such as
cichlids, also possess pharyngeal teeth, the cypriniformes' teeth grind against a chewing pad on the base of the skull, instead of an upper pharyngeal jaw. Brackish water and marine cyprinids are invariably
anadromous, swimming upstream into rivers to spawn. The enigmatic
mountain carps are a small group of mountain stream fishes confined to
Southeast Asia. Sometimes separated as family Psilorhynchidae, they seem to be specially-adapted Cyprinidae.
The Balitoridae and Gyrinocheilidae are families of mountain stream fishes feeding on algae and small invertebrates. They are found only in tropical and subtropical Asia. While the former are a speciose group, the latter contain only a handful of species. The suckers (Catostomidae) are found in temperate North America and eastern Asia. These large fishes are similar to carps in appearance and ecology. The Cobitidae are common across Eurasia and parts of North Africa. A mid-sized group like the suckers, they are rather similar to catfish in appearance and behaviour, feeding primarily off the substrate and equipped with barbels to help them locate food at night or in murky conditions. The Cobitidae, Balitoridae, and Gyrinocheilidae are called loaches, although it seems that the last do not belong to the lineage of "true" loaches but are related to the suckers.
Systematics and evolution
is a hillstream loach. Closely related to true loaches, like these they have barbels.]]
(
Gyrinocheilus aymonieri), one of the sucking loaches which are distant from other "loaches".]]
, a small sucker.]]
Historically these included all the forms now placed in the
superorder Ostariophysi except the catfish, which were placed in the order
Siluriformes. By this definition, the Cypriniformes were
paraphyletic, so recently the orders
Gonorhynchiformes,
Characiformes (
characins and allies), and
Gymnotiformes (
knifefishes and
electric eels) have been separated out to form their own
monophyletic orders.
The families of Cypriniformes are traditionally divided into two superfamilies. Superfamily Cyprinioidea contains the carps and minnows (Cyprinidae) and, according to some, also the mysterious mountain carps as the family Psilorhynchidae. The superfamily Cobitioidea contains hillstream loaches (Balitoridae), suckers (Catostomidae), true loaches (Cobitidae), and sucking loaches (Gyrinocheilidae) in the traditional system. However, their divergence probably occurred only with the splitting-up of Pangaea in the Jurassic, maybe 160 million years ago. By 110 mya, the plate tectonics evidence indicates that the Laurasian Cypriniformes must have been distinct from their Gondwanan relatives.
Cypriniformes is thought to have originated in south-east Asia, where the most diversity of this group is found today. The alternative hypothesis is that they began in South America, similar to the other otophysans. If this were the case, they would have spread to Asia through Africa or North America. As the Characiformes began to diversify and spread, they may have out-competed South American basal cypriniforms in Africa, where more advanced cypriniforms survive and coexist with characiforms.
The earliest fossils are already assignable to the living family Catostomidae; from the Paleocene of Alberta, they are roughly 60 million years old. During the Eocene (55-35 mya), catostomids and cyprinids spread throughout Asia. In the Oligocene, around 30 mya, advanced cyprinids began to out-compete catostomids wherever they were sympatric, causing a decline of the suckers. Cyprinids reached North America and Europe by about the same time, and Africa in the early Miocene (some 23-20 mya). The cypriniforms spread to North America through the Bering land bridge, which formed and disappeared again several times during the many millions of years of cypriniform evolution.
In science, one of the most famous members of the Cypriniformes is the zebrafish (Danio rerio). The zebrafish is one of the most important vertebrate model organisms in biological and biochemical sciences, being used in many kinds of experiments. As, during early development, the zebrafish has a nearly transparent body, it is ideal for studying developmental biology. It is also used for the elucidation of biochemical signaling pathways, among others
Threats and extinction
(
Gila crassicauda) is globally
extinct since about 1960.]]
Habitat destruction,
damming of upland rivers,
pollution and in some cases
overfishing for food or pet trade have driven some Cypriniformes to the brink of
extinction or even beyond. In particular, Cyprinidae of southwestern
North America have been severely affected; a considerable number went entirely extinct after settlement by Europeans. For example, in 1900 the
Thicktail Chub (
Gila crassicauda) was the most common freshwater fish found in
California; 70 years later not a single living individual existed anymore.
s (Epalzeorhynchos bicolor) remain in the wild today.]]
The well-known Red-tailed Black Shark (Epalzeorhynchos bicolor) from the Mae Klong river of The Bridge on the River Kwai fame possibly only survives in captivity. Ironically, while pollution and other forms of overuse by humans have driven it from its native home, it is bred for the aquarium fish trade by the thousands. The Yarqon Bleak (Acanthobrama telavivensis) from the Yarqon River had to be rescued into captivity from imminent extinction; new populations have apparently been established again successfully from captive stock. Balitoridae and Cobitidae, meanwhile, contain a very large number of species about which essentially nothing is known except how they look like and where they were first found.
Acanthobrama hulensis
Gökçe Balığı, Alburnus akili
Barbus microbarbis
Snake River Sucker, Chasmistes muriei
Chondrostoma scodrense
Cyprinus yilongensis
Evarra bustamantei
Evarra eigenmanni
Evarra tlahuacensis
Thicktail Chub, Gila crassicauda
Pahranagat Spinedace, Lepidomeda altivelis
Harelip Sucker, Moxostoma lacerum
Ameca Shiner, Notropis amecae
Durango Shiner, Notropis aulidion
Phantom Shiner, Notropis orca
Salado Shiner, Notropis saladonis
Clear Lake Splittail, Pogonichthys ciscoides
Las Vegas Dace, Rhinichthys deaconi
Stumptooth Minnow, Stypodon signifer
Telestes ukliva
Footnotes
References
(2005): The biogeography of otophysan fishes (Ostariophysi: Otophysi): a new appraisal.
J. Biogeogr. 32(2): 287–294. (HTML abstract)
(2004a):
Family Balitoridae - River loaches. Version of 2004-NOV-22. Retrieved 2007-03-05.
(2004b):
Family Catostomidae - Suckers. Version of 2004-NOV-22. Retrieved 2007-03-05.
(2004c):
Family Cobitidae - Loaches. Version of 2004-NOV-22. Retrieved 2007-03-05.
(2004d):
Family Cyprinidae - Minnows or carps. Version of 2004-NOV-22. Retrieved 2007-03-05.
(2004e):
Family Gyrinocheilidae - Algae eaters. Version of 2004-NOV-22. Retrieved 2007-03-05.
(2004f):
Family Psilorhynchidae - Mountain carps. Version of 2004-NOV-22. Retrieved 2007-03-05.
(2005):
Order Summary for Cypriniformes. Version of 2005-FEB-15. Retrieved 2007-03-05.
(2006):
Florida's Exotic Freshwater Fishes. Retrieved 2007-03-05.
(2005):
Cyprinus carpio (Linnaeus, 1758). Version of 2005-08-03. Retrieved 2007-05-03.
(2008): Phylogenetic position of the enigmatic genus
Psilorhynchus (Ostariophysi: Cypriniformes): Evidence from the mitochondrial genome.
Mol. Phylogenet. Evol. 47: 419–425. (HTML abstract)
(1997):
The Diversity of Fishes. Blackwell Publishing. ISBN 0-86542-256-7
(2007):
[www.iucnredlist.org 2007 IUCN Red List of Threatened Species].
(2006):
Fishes of the World. John Wiley & Sons, Inc. ISBN 0471250317
[2007]:
FishBase -
Tribolodon brandtii. Retrieved 2007-03-05.
(2003): Mitochondrial Genomics of Ostariophysan Fishes: Perspectives on Phylogeny and Biogeography.
J. Mol. Evol. 56(4): 464–472. (HTML abstract)
External links
Cypriniformes Tree of Life
Category:Fish of Africa
Category:Fish of Europe
Category:Fish of Asia
Category:Fish of North America
Category:Fish of Central America
