- Related Topics:
- catfish
- schilbeid catfish
- Otophysi
- Cypriniformes
- Anotophysi
ostariophysan
-
What are ostariophysan fish?
Ostariophysans are a superorder of bony fish that includes around 8,000 species, making up almost a quarter of all known bony fish species. This group contains a diverse array of freshwater fish, such as minnows, carps, piranhas, electric eels, and catfish. They are found worldwide, except in Greenland and Antarctica, and live in various freshwater habitats.
A key feature of ostariophysans is the Weberian apparatus, a unique structure that enhances their hearing. This apparatus is a chain of small bones that connects the swim bladder to the inner ear, allowing them to perceive sound more acutely than other fish. They also have a unique chemical communication warning system.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
Where can ostariophysan fish be found around the world?
Ostariophysan fish, comprising about 8,000 species, are the dominant fishes in fresh water across tropical, temperate, and subarctic regions worldwide, except for Greenland and Antarctica. A few species can also be found in brackish waters, and some reside in marine environments along tropical and subtropical coasts.
These fish have adapted to various habitats, from mountain streams to sluggish rivers, ponds, lakes, and even subterranean waters. Some species display unique adaptations like holdfast organs for living in torrential currents or a reduction or loss of eyes for life in total darkness. Familiar members of this group include minnows, carps, piranhas, electric eels, and catfish.
5 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What are some common types of ostariophysan fish?
Ostariophysans are a superorder of bony fish containing about 8,000 species, most of which are freshwater fish. They include familiar species such as minnows, carps, piranhas, electric eels, and catfishes.
The largest order in Ostariophysi is Siluriformes, which includes all catfish species. The remaining families are distributed among these orders:
* Cypriniformes (minnows, carps, suckers)
* Characiformes (characins, hatchetfishes, pencil fishes)
* Gymnotiformes (electric eels)
* Gonorynchiformes (milkfish, beaked sandfishes)Ostariophysans owe their success to two remarkable features: acute hearing and a unique chemical communication warning system. They are the dominant fishes in nearly all freshwater habitats throughout the tropical, temperate, and subarctic regions of the world.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What special features do ostariophysan fish have?
Ostariophysans, a group containing about 8,000 species of bony fishes, are the dominant fishes in freshwater habitats throughout the tropical, temperate, and subarctic regions of the world.
A distinctive feature of ostariophysans is the Weberian apparatus. This structure is a chain of small bones that link the swim bladder and inner ear, enhancing hearing by conducting pressure changes from sound waves to the ear.
Many ostariophysans also exhibit fascinating behaviors, such as nest building, oral incubation, communication by chemical secretions, and the production of sound and electricity. Some species have structural adaptations like holdfast organs and specialized respiratory mechanisms that allow them to live in mountain streams with strong currents.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
How do ostariophysan fish protect themselves from predators?
Ostariophysan fish have developed several strategies to protect themselves from predators:
- Alarm Substances When the skin is injured, special cells in the epidermis secrete an alarm substance, warning other fish in the school of potential danger.
- Protective Coloration Many smaller ostariophysans rely on somber colors to camouflage themselves, providing a passive defense. Some species, like oarfish, swim vertically to further camouflage themselves in deep water.
- Defensive Anatomy Certain species have spines in their dorsal and pectoral fins, offering protection. Some catfishes have venom glands at the base of these spines, which can cause painful injuries.
- Powerful Jaws and Teeth Larger species, such as the African tigerfish and piranhas, possess powerful jaws and strong teeth, which serve as effective weapons for both defense and offense.
4 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
Why are ostariophysan fish important to freshwater ecosystems?
Ostariophysan fish are vital to freshwater ecosystems due to their diverse ecological roles and economic importance. As the dominant fish group in tropical, temperate, and subarctic freshwaters, they inhabit various habitats, from mountain streams to lakes.
Their feeding habits range from phytoplankton strainers to voracious predators, influencing energy flow and nutrient cycling. Many species are utilized for food, supporting commercial fisheries and aquaculture. Some species control vegetation, while others serve as experimental animals in scientific research. Though some may act as pests or hosts for parasites, ostariophysans overall play key roles in maintaining the balance and health of freshwater ecosystems.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
ostariophysan, (superorder Ostariophysi), any of about 8,000 species of bony fishes belonging to a group that includes the majority of freshwater fishes throughout the world. Familiar representatives of this group are the minnows, suckers, carps, piranhas, electric eels, and innumerable catfishes. Humans consume huge quantities of ostariophysans for food. Some of these fishes are also popular in tropical aquariums. A few harmful species can inflict painful injuries; some others serve as intermediate hosts for parasites of humans. Many of these fishes exhibit strange and fascinating behaviour such as nest building, oral incubation, egg laying in mollusk shells, walking and flying, air breathing, production of sound and electricity, and communication by chemical secretions.
The largest order in superorder Ostariophysi is Siluriformes, containing the 35 recognized families of catfishes. The remaining 33 families in Ostariophysi are distributed among the orders Cypriniformes (minnows, carps, suckers, and other fishes), Characiformes (characins, hatchetfishes, pencil fishes, and others), Gymnotiformes (electric eels and other fishes), and Gonorynchiformes (the milkfish, beaked sandfishes, and others). These orders are divided into two groups, or series, based on the presence or absence of the Weberian apparatus, a bony connection between the swim bladder and the inner ear that enhances the perception of sound. Series Anotophysi, containing only the order Gonorynchiformes, does not possess a true Weberian apparatus. Series Otophysi is made up of the four remaining orders, the members of which possess a true Weberian apparatus.
General features
Size range and diversity of structure
Most ostariophysans are small to moderate in size, from 2 to 30 cm (about 1 to 12 inches) long. Others rank among the giants of the freshwater world. The elegant mahseer (Cyprinidae) of Asia grows to 2 metres (about 7 feet) long and weighs 90 kg (200 pounds), and the wels, a Eurasian catfish (Siluridae), attains a length of 4.5 metres (15 feet) and a weight of 300 kg (660 pounds). The extent of morphological diversity is at least as great as that in any other group of living vertebrates.
" height="20" alt="HEW Logo">
Ostariophysans abound in nearly all freshwater habitats, including subterranean caverns and those on all major landmasses and continental islands of the world, except for Greenland and Antarctica. A few live in brackish waters, and two families consist largely of marine species. Approximately 8,000 species are recognized, nearly one-fourth of all known species of bony fishes. Their undisputed success may be attributed at least in part to two remarkable features: a sense of hearing more acute than that in any other group of fish and a warning system by chemical communication unique among fishes.
Importance
Many moderate to large ostariophysans are utilized for food, and commercial fisheries harvest huge quantities of marketable species. The common carp (Cyprinus carpio), native to China, has been introduced nearly worldwide and is extensively cultured in the warmer regions. Other Chinese carp under cultivation include the grass carp (Ctenopharyngodon), silver carp (Hypothalmichthys), snail carp (Mylopharyngodon), and bighead carp (Aristichthys). Culture of the channel catfish (Ictalurus punctatus) is an important industry in the southern United States. Numerous ostariophysans provide sport fishers with recreation and food; several, such as the mahseers (several species of Tor) of Asia and the dorado (Salminus maxillosus) of South America, rank among the world’s prized game fish.
Among the most popular aquarium species are the characins, tetras, rasboras, danios, barbs, loaches, and catfishes. Adaptability of many ostariophysans to aquarium life has resulted in their widespread use as experimental animals in scientific research. Foremost among these are the goldfish (Carassius auratus), the common carp, and the zebra fish (Danio rerio).
In eastern Asia and parts of Europe, humans frequently become infected with liver flukes acquired by eating raw or imperfectly cooked fish. The carps, especially Ctenopharyngodon idellus, are the second intermediate host of the Chinese liver fluke (Clonorchis sinensis). Many cyprinids serve as intermediate hosts for the cat liver fluke (Opisthorchis felineus). Domestic animals similarly become infected with flukes and tapeworms.
The trusted destination for professionals, college students, and lifelong learners.
SUBSCRIBE
Some ostariophysans are pests or are potentially dangerous to people. The common carp is a nuisance in many localities in the United States. Introduced species such as the walking catfish (Clarias batrachus) pose a serious threat to the native fauna. In South America, on occasion, the piranha (Serrasalmus) voraciously attacks humans and domestic animals, and the diminutive candiru (Vandellia cirrhosa) can penetrate the urogenital openings of human bathers and cause intense pain and hemorrhaging.