Snakehead Temporal range: Eocene to recent, | |
---|---|
Northern snakehead, Channa argus | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Anabantiformes |
Suborder: | Channoidei Berg, 1940 |
Family: | Channidae Fowler, 1934 |
Genera | |
see text |
The snakeheads are members of the freshwater perciform fish family Channidae, native to parts of Africa and Asia. These elongated, predatory fish are distinguished by their long dorsal fins, large mouths, and shiny teeth. They breathe air with gills, which allows them to migrate short distances over land. They have suprabranchial organs, which are primitive forms of labyrinth organs, that develop when they grow older. [1] The two extant genera are Channa in Asia and Parachanna in Africa, consisting of more than 50 species.
They are valuable as a food source and have become notorious as an intentionally released invasive species. These fish have been kept as pets but as they get larger, people let them go into ponds, lakes, and rivers, making these fish invasive.
The various species of snakeheads differ greatly in size; dwarf snakeheads, such as Channa orientalis , do not surpass 25 cm (10 in) in length. Most other snakeheads reach between 30 and 90 cm (12 and 35 in). Five species ( C. argus , C. barca , C. marulius , C. micropeltes , and C. striata ) can reach 1 m (3 ft 3 in) or more. [2]
Snakeheads are thrust-feeders[ clarification needed ] that consume plankton, aquatic insects, and mollusks when small. As adults, they mostly feed on other fish (such as carp) or on frogs. In rare cases, small rodents such as rats are eaten.
The Channidae are well represented in the fossil record and known from numerous specimens. They likely originated in the south Himalayan region of the Indian subcontinent (modern-day northern India and eastern Pakistan) at least 50 million years ago (Mya), during the Early Eocene epoch. Two of the earliest known species, Eochanna chorlakkiensis and Anchichanna kuldanensis, have both been found in the Middle Eocene of Pakistan. [3] [4] By 17 Mya, during the Early Miocene, Channidae had spread into western and central Eurasia, and by 8 Mya, during the late Tortonian, they existed throughout Africa and East Asia. [5] As Channidae are adapted to climates of high precipitation with mean temperatures of 20 °C (68 °F), their migrations into Europe and Asia correspond to the development of the Intertropical Convergence Zone, which increased air humidity, and the intensification of the East Asian monsoon. Both weather patterns emerged due to greater vertical growth of the Alps, Pyrenees, and Himalayas, which affected Eurasian climatic patterns. [5]
Snakeheads can become invasive species and cause ecological damage because, in many areas to which they are not native, the absence of natural enemies makes them an apex predator. Not only can they breathe air, but they can also survive on land for up to four days, provided they are wet, and are known to migrate up to 400 m (1/4 mi) on wet land to other bodies of water by wriggling with their bodies and fins. National Geographic has referred to snakeheads as "fishzilla" [6] and the National Geographic Channel reported the "northern snakehead reaches sexual maturity by age two or three. Each spawning-age female can release up to 15,000 eggs at once. Snakeheads can mate as often as five times a year. This means in just two years, a single female can release up to 150,000 eggs." [7]
"Since 2002, it has been illegal to possess a live snakehead in many U.S. states, where they are considered a destructive invasive species." [8] Virginia has criminalized the "introduction" of snakeheads into the state without specific authorization, although the relevant statute does not explain whether mere importation is sufficient to constitute "introduction into the Commonwealth" or whether instead release into the environment is required. [9]
Humans have been introducing snakeheads to nonindigenous waters for over 100 years. In parts of Asia and Africa, the snakehead is considered a valuable food fish since the flesh is very tender, and is produced in aquacultures (fisheries motivation) or by accidental release (as was the case in Crofton, Maryland). [10] Examples of the introduction of snakeheads to nonindigenous waters include:
Snakeheads became a national news topic in the United States because of the appearance of C. argus, commonly known as northern snakeheads, spawning in a Crofton, Maryland, pond in 2002. [8] Northern snakeheads became permanently established in the Potomac River around 2004, [11] and possibly established in Florida. [8] In about 120 mi (190 km) of river, the population has surpassed 21,000 individuals. [12]
According to the United States Environmental Protection Agency, snakeheads have also been spotted in California, Delaware, Florida, Georgia, Hawaii, Maine, Maryland, Massachusetts, Virginia, Louisiana, [13] and Rhode Island. [14] Snakeheads have also been spotted in New York State according to the state's Department of Environmental Conservation. [15] Snakeheads have been caught in New Jersey since at least 2008 and, according to the New Jersey Department of Environmental Protection, the snakehead population appears to be growing and expanding its distribution. Due to the extensive habitat available and sheer size of the Delaware River, complete eradication of the species does not appear to be feasible. [16]
According to the International Game Fish Association, two 13.61 kg (30 lb 0 oz) giant snakeheads, both from Rawang, Malaysia are tied for the record. [17]
Snakeheads are valuable food fish. Called nga yant in Burmese and in Manipur [Meiteilon] as porom, they are prized fish eaten in a variety of ways.In south india specifically the state of Kerala natively called Varal (Malayalam: വരാൽ) this fish is used to make Varal curry which is very famous in the state. In Vietnam, they are called cá lóc, cá quả, or cá chuối, and are served in clay-pot, steamed, and pickled preparations. Larger species, such as C. striata, C. maculata, and Parachanna obscura , are farmed in aquaculture. In the United States, chefs have suggested controlling the snakehead invasion by serving them in restaurants. [18] In Indonesia, snakehead fish, called ikan gabus, are served as the main parts of traditional dishes such as the Betawi people's pucung gabus, and considered to be a delicacy due to their rarity in the wild and in aquaculture, as they are harder to raise than other popular freshwater fish such as catfish and carp. In the Philippines, where it's called "Haluan" (the Tagalogs call it "Dalag"), it is a favorite among Maguindanaons and Iranuns.
The snakeheads comprise two extant genera:
Two other genera are only known from fossils:
The genus Aenigmachanna was initially classified in Channidae upon its discovery, but analysis supports it being reclassified into its own family Aenigmachannidae. [20]
After its release in non-native North American waters, either accidentally or intentionally, the aggressive and predator-free snakehead's reputation as a "Frankenfish" [21] or "monster fish" has become part of popular culture. [22] Besides mentions on TV shows such as The Sopranos, [23] The Office [24] , CSI:NY episode "Sangre por Sangre", Central Park episode "A Fish Called Snakehead", and Bless the Harts episode "Crappy Death Day", the snakehead has been featured in four Sci-fi Channel original pictures entitled Snakehead Terror , Frankenfish , Swarm of the Snakehead , and Snakehead Swamp.
In the Animal Planet TV series River Monsters , Jeremy Wade shows a dramatization of a snakehead, "the fish from hell", stalking an unsuspecting baby and a Chihuahua. With the help of a snakehead researcher, however, Wade shows that although it is capable of living outside of water and is able to move on land, its weak pectoral muscles make movement difficult and render the snakehead an unlikely "stalker" on land.
In the animated series Penguins of Madagascar, the snakehead is portrayed as a ferocious killer fish of monstrous size with a mouth full of razor-sharp teeth that scared off a family of ducks from their pond in Central Park. The penguins go to the park to investigate and end up running into the snakehead. All of the penguins (except Skipper) are terrified of the fish. But in the end, the penguins face their fears and build a submarine to hunt down and kill the snakehead. Eventually, the team defeats the fish by tossing a soda bottle, which was shaken up earlier by King Julien when he attempted to christen the penguin’s submarine, and the bottle explodes, killing the snakehead, which is later served as sushi by the penguins. [25]
The northern snakehead is a species of snakehead fish native to temperate East Asia, in China, Russia, North Korea, and South Korea. Their natural range goes from the Amur River watershed in Siberia and Manchuria down to Hainan. It is an important food fish and one of the most cultivated in its native region, with an estimated 500 short tons (450 t) produced every year in China and Korea alone. Due to this, the northern snakehead has been exported throughout the world and has managed to establish non-native populations in Central Asia and North America. In the United States, it is found in Pennsylvania, Virginia, West Virginia, Delaware, Maryland, North Carolina, Arkansas and Mississippi.
Channa is a genus of predatory fish in the family Channidae, commonly known as snakeheads, native to freshwater habitats in Asia. This genus contains about 50 scientifically described species. The genus has a wide natural distribution extending from Iraq in the west, to Indonesia and China in the east, and parts of Siberia in the Far East. A particularly high richness of species exists in Myanmar (Burma) and northeastern India, and many Channa species live nowhere else. In contrast, a few widespread species have been introduced to several regions outside their natural range, where they often become invasive. The large and medium-sized Channa species are among the most common staple food fish in several Asian countries, and they are extensively cultured. Apart from their importance as a food fish, snakeheads are consumed in some regions as a traditional medicine for wound healing and reducing postoperative pain and discomfort, and collected for the international aquarium pet trade.
Parachanna is a genus of snakeheads native to freshwater habitats in tropical Africa. Three recognized extant (living) species are in this genus, but a phylogenetic study from 2017 indicates that a fourth, currently undescribed species also exists.
Channa bleheri is a species of dwarf snakehead that is endemic to the Brahmaputra River basin in the Indian states of Assam and Arunachal Pradesh. It is among the most colorful species of snakehead.
Dwarf snakehead is a term coined by aquarists to describe a group of Channa snakehead fishes growing to about 25 cm (10 in) maximum. They are found in freshwater habitats in South and Southeast Asia, and southern China.
The forest snakehead is a species of snakehead, a fish of the family Channidae. Its range includes most of Southeast Asia and parts of southern China. It lives in forest streams and can reach 40 cm (16 in) in length. The forest snakehead is known in Thai language as pla krasong. Khmer language called it កញ្ជនជៃ, Indonesians named it kehung, while in Malaysia, they called it ikan bujuk in Malay Language and in Vietnamese its name is cá lóc dày
Channa gachua, the dwarf snakehead, is a species of fish in the family Channidae. The name "dwarf snakehead" is also used for several other species of small snakeheads. C. gachua is native to freshwater habitats in southern Asia, where it has a wide distribution from Iran to Indonesia. This fish is considered to be a species complex, a group of several closely related taxa with one name. It is likely at least three to four different species, and further research may differentiate them. A few species such as Channa harcourtbutleri have been separated from the complex in recent decades. The easternmost population of C. gachua is often recognized as a separate species C. limbata, while the isolated Sri Lankan population often is recognized as C. kelaartii.
Channa striata, the striped snakehead, is a species of snakehead fish. It is also known as the common snakehead, chevron snakehead, or snakehead murrel and generally referred simply as mudfish. It is native to South and Southeast Asia, and has been introduced to some Pacific Islands. Reports from Madagascar and Hawaii are misidentifications of C. maculata.
Mudfish most commonly refers to all species of Neochanna, native to New Zealand and south-eastern Australia.
Channa micropeltes, giant snakehead, giant mudfish or toman harimau, is among the largest species in the family Channidae, capable of growing to 1.3 m (4.3 ft) in length and a weight of 20 kg (44 lb). It is native to the fresh waters of Southeast Asia, but has also been introduced elsewhere and is considered invasive in Taiwan. Other names include shol machh in Bengali, red snakehead, redline snakehead, and ikan toman.
The Ceylon snakehead is a species of snakehead found in freshwater habitats, typically shaded streams, in southwestern Sri Lanka.
Channa marulius, the bullseye snakehead or great snakehead, is a large species of snakehead native to South Asia. Populations in Southeast Asia are now regarded as separate species.
Parachanna fayumensis, is an extinct member of the snakehead fish family (Channidae) known from fossil records only. It is the oldest member of this family known from Africa. It differs from Parachanna insignis, P. africana and P. obscura by presence of prominent raised tooth patch with well-developed tooth sockets on a ventral surface of parasphenoid posterior end. Several skull bones were found in the upper Eocene and lower Oligocene Jebel Qatrani Formation of the Fayum Depression, Egypt. The zoogeographic importance of this fossil material is that it suggests a Channid migration from India to Africa long before the Miocene.
The Malabar snakehead is a vulnerable species of snakehead from fresh water in the Western Ghats in India. Until 2011, its scientific name was usually considered to be a synonym of C. micropeltes, the giant snakehead.
The obscure snakehead is a medium-sized carnivorous fish that has an elongated shape tapered on both ends and is covered in medium circular scales (cycloid). The head, resembling a snake, is long and depressed anteriorly and covered with cycloid scales slightly larger than those scales on the body. This species is found in central Africa along the western coastline from as far north as Senegal to as far south as Zaire and into central Africa into southwest Sudan.
Channa pleurophthalma, the ocellated snakehead is a species of Southeast Asian freshwater fish in the snakehead family.
The Anabantiformes, is an order of bony fish (Teleostei) proposed in 2009. They are collectively known as labyrinth fish, are an order of air-breathing freshwater ray-finned fish with two suborders, five families and at least 207 species. In addition, some authorities expand the order to include the suborder Nandoidei, which includes three families - the Nandidae, Badidae and Pristolepididae - that appear to be closely related to the Anabantiformes. The order, and these three related families, are part of a monophyletic clade which is a sister clade to the Ovalentaria, the other orders in the clade being Synbranchiformes, Carangiformes, Istiophoriformes and Pleuronectiformes. This clade is sometimes referred to as the Carangaria but is left unnamed and unranked in Fishes of the World. This group of fish are found in Asia and Africa, with some species introduced in United States of America.
Channa pulchra is a species of snakehead fish in the family Channidae which is native to Myanmar. It was first described in 2007 by R. Britz from a specimen collected from the Kyeintali Chaung (stream) basin in Rakhine Yoma, western Myanmar. The fish is found in streams that are fast flowing, clear, highly oxygenated and relatively cold (subtropical). It is of little food value but getting popularity as an aquarium fish recently.
Aenigmachanna gollum, the Gollum snakehead, is a species of aquifer-dwelling dragon snakehead fish that is endemic to the Indian state of Kerala.
Channa aurolineata is a species of Asian snakehead in the family Channidae. It is found natively in most of Myanmar's waterways as well as the Mae Khlong drainage in Thailand. There is also an invasive population found in Southeast Florida, United States. This species was recently split from C. marulius, the bullseye snakehead, and confirmed as a separate species in 2018; and the Florida and Thailand populations were not discovered to be C. aurolineata until even more recently in 2019. Before this, the Thailand population's species was unknown and the Florida ones were assumed to be C. marulius. C. aurolineata was able to be separated as a new species and identified in other areas due to slight differences in color pattern, lateral line scale and fin ray morphology, and DNA structure from the other species in the marulius complex.