Snakehead Fish

The snakehead fish is considered a member of the perciform fish family Channidae which is found in freshwater and are native to Africa as well as Asia. This is a predatory fish having an elongated body, dorsal fins, largemouth as well as shiny and sharp teeth. They have the ability to breathe the air through gills because of which they can migrate overland for short distances as well. The size of different species of this fish can differ. For example, Channa Orientalis does not surpass 25cm or 10 in whereas most others can grow between 30 to 90 cm or 12 to 35 in. Besides these, some other species can reach up to 1 m or more such as Channa argus, Channa Barca, Channa Marulius, Channa micropeltes Barcad, Channa striata. 

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Description of Snakehead Fish

These are the species of fish that are not considered native to North America and are indigenous to Africa as well as Asia. They are freshwater air-breathing species. Scientifically, they can be divided into two categories which are:

• Channa: snakeheads found in  Asia, Malaysia, & Indonesia

• Parachanna: snakeheads found in Africa

They got the national attention of the US when in 2002 and 2004, the northern snakehead was found in the pond of Maryland and Potomac river of Maryland. These species are considered invasive because of their potential to threaten the native's fishes and aquatic ecosystem.  A mature female snakehead can carry almost as many as 50,000 eggs. Though all of them will not be developed. Some of them will be eaten by other small fishes or insects. These eggs can hatch in 24 to 48 hours depending on the temperature of the water. For their food, when they are small, they usually consume plankton, insects, mollusks, etc whereas they eat other fishes or frogs when they become adults. Sometimes they also eat small rodents as well in rare cases.

History

The Channidae are known well by other specimens and are available in the records of the fossils. They emerged in the southern Himalayas which are situated nowadays in northern India and eastern Pakistan. It emerged 50 million years ago during the early Eocene epoch. Eochanna Chorlakkiensis and Anchichanna Kuldanensis are the two early species that are found in the middle Eocene of Pakistan. Channidae had spread in the western and central Eurasia by 17 million years ago and by 8 mya, they emerged in Africa and East Asia during the late tortorian. Channidae knows how to adapt themselves in the climate of high perception with mean temperatures of 20° C and they do migrate from Europe and Asia. Their migration led to the development of intertropical convergence zones that increased air humidity and the escalation of the East Asian monsoon. Due to greater vertical growth of the Alps, Pureness and Himalayas that affected Eurasian climatic patterns because of this, weather patterns emerged.

 The snakeheads are an invasive species. In many areas, they are not known to the place and there they are known as natural enemies to the other species living there that cause ecological damage. They can breathe air and also survive on land for 4 days if they are wet and they migrate up to 400 m on the land that is wet. They are referred to as " fishzilla" by National Geographic and at the age of 2 or 3, they reach sexual maturity. Each female can release 15,000 eggs at once. Snakeheads can make mates at least 5 times in a year and in just 2 years a single female snakehead produces 15,000 eggs. In the USA, it is illegal to possess a live snakehead as they are destructive species.

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Physical Description

The elongated bodies of snakehead fish have given them this name. They can grow up to 3 feet long in the areas where they are introduced and even larger than 3 feet in their native areas.  They used to have sharp and dagger-like teeth as well as canine teeth in the lower jaw. The dorsal fin, as well as the anal fin, helps in making them good and speedy swimmers. The scales of their bodies are golden tan to pale brown and also different splotches along their flank can also be found.  If we talk about snakehead fish walking, the juveniles of these species are skilled in moving the short distances on land but as they get older, it becomes difficult for them to do so. They during drought, burrow under the mud whereas migrating during the rainstorms.

Air-breathing Feature

This species has a special separate chamber next to their gills which are known as a suprabranchial organ which allows this fish to take oxygen directly from the air. This feature allows them to grow in low oxygen as well, in stagnant water bodies such as swamps, muddy rivers, canals, ponds, etc. and not only this, they can survive up to 4 days outside the water. Often in the winter months, they can also respire under the water with the help of their gills. If we talk about the summer or warm conditions when more oxygen is required, they usually breathe through suprabranchial organs.

Reproduction and Offsprings

These fish species can reach their sexual maturity almost between one to three years which depends upon the growing conditions and usually breed during April to August. They have the ability to spawn up to 5 times and every time can give thousands of eggs which are buoyant and orange-yellow eggs. Sometimes they give almost 50,000 eggs per annum and they often create floating nests that are made up of vegetation in order to protect their eggs. The parents of younger ones used to defend and take care of them for several weeks and are known to attack people who try to get close to them.

As Food

This snake fish is considered as valuable food which is called "nga yant" in Burmese whereas as "porom" in Manipur and they are called prized fish which is being eaten in various ways. They are called cá lóc, cá quả, or cá chuối in Vietnam and are being prized in the clay pot and also steamed & pickled preparations. Large species of this fish are farmed in aquaculture. They are also being suggested as one of the controlling measures in the US by serving them in restaurants. Besides these, they are called "ikan gabus" which are served in their traditional dishes as one of the main parts in Indonesia such as pucung gabus traditional dish. These snake type fish are considered fragile fish due to their rare presence in the wild or aquaculture because they are difficult to raise than other types of freshwater fish.

Classification

Some of the species and their description are given below if fisherman wants to keep them:

Golden Cobra Snakehead 

They are known as Channa aurantimaculata Scientifically and also called as Orange Spotted Snakehead. They can reach up to 40 cm or 16 in and are aggressive species and should be kept alone. They belong to Northern Assam of India and the cool temperature is best for this. The parameters can be from 20° to 26° C or 68° to 79° F temperature and pH of 6.0 to 7.0 whereas GH to 10.

Red Snakehead 

This species of snakehead is known as Channa micropeltes Scientifically and also Giant Snakehead. They have the capability to grow up to 1m to 39 in or even more and it is considered the largest snakehead in captivity. A large tank Imis required to keep an adult and giant snakehead. They are also one of the most aggressive species of snakehead and can attack other mates. They have large teeth and can use them on humans as well.   The juveniles of this species have attractive colours running their whole body such as bright orange stripes whereas when they become adults they have a dull blue colour. They can be maintained in temperature of 26° to 28° C or 79° to 82° F along with acidity as well as hardness by avoiding the extremes. The only experienced fishkeeper should take care of this fish.

Dwarf Snakehead 

Scientifically, they are known as Channa gachua and considered as one of the widest range species of snakeheads. It is generally said that members of Dwarf species belong to a complex of several species. This is acknowledged by referring to the population of South-East Asia. The dwarfs, especially from Northern India, need to be maintained at water parameters of 18° to 25°C or 64° to 77° F with pH levels of 6.0 to 7.5 or GH of 6 to 8. They can reach up to 20 cm or 7.8 in only and are relatively docile and can be kept in community tanks.

Emperor Snakehead 

They are called Channa marulioides scientifically and have the ability to reach up to 65 cm or 26 in. They are considered as suitable for specific tanks or with other large tank mates and can be kept at 24° to 28° C or 75° to 82° F and pH range of 6.0 to 7.0 whereas GH of 10.

Rainbow Snakehead 

They are known as Channa bleheri scientifically. They are considered as small as well as peaceful species and members of the dwarf complex. They are called rainbow because they are the most colourful among all the snakeheads and can reach up to 20 cm or 7.8 in and are suited for the community tanks. As similar to dwarf snakeheads, they are advised to keep at cooler temperatures. 

Banka Snakehead 

They are called Channa bankanensis scientifically and in terms of water conditions, they are probably considered as most demanding. They belong to the black water habitats which are extremely acidic in nature such as pH of 2.8 whereas it's not necessary to maintain it at high acidic levels and pH can be kept lower as 6.0 or lower than this because too high a level can cause infections to them. They also do better in humic or tannins acids and thus peat would be good in the filtration. They can grow up to 23 cm or 9 in only but they are aggressive. 

Splendid Snakehead 

The Scientific name of this snakehead species is Channa Lucius and they have the capability to reach up to 40 cm or 15.7 in. They are considered one of the larger species. Thus, in aquaculture, they need to be taken care of accordingly. They are aggressive and should be kept with large robust tank mates. For them, water parameters that need to be followed are 24° to 28° C or 75° to 82° F and pH of 5.0 to 6.5 whereas GH to 8.

Ocellated Snakehead 

Channa pleurophthalma is the Scientific name of this snakehead species which is found in South East Asia where it is one of the most attractive species. This fish differs from other types of snakeheads in terms of shape & more laterally compressed body whereas other species usually have cylindrical bodies. They are used to find in brown water habitats in the wild which are having a little higher acidity than the usual parameters such as pH 5.0 - 5.6 but acclimatized to 6.0 to 7.0 pH ranges in the aquarium. This species has to be maintained in water that is not too hard such as 24° to 28°C or 75° to 82°F. They are relatively considered peaceful and if you want to keep them, can be kept with large and robust tank mates as they grow up to 45 cm or 18 in.

Spotted Snakehead 

The scientific name of this species is Channa punctata which is native to India. They are considered a common species which have an extensive range of habitats such as from mild temperate to tropical areas. They have the ability to tolerate a wide range of temperatures such as from 9° to 40°C or 48° to 104° F. Besides these, the various experiments that have been conducted shows that they are able to tolerate large pH ranges as well. Thus, water parameters are also not that important if the extremes are avoided. A pretty small species that reaches 30 cm or 12 in,  this snakehead is, although competitive, sufficient for the handiest large, strong tank buddies to be considered.

Chevron Snakehead 

They are also Channa striata scientifically and considered as one of the most robust fishes of freshwater. Mostly the parameters of water are not very important but concerns for avoiding the extremes are still there. This is one of the large species which can range up to 90 cm or 35 in. It is not considered as suited for the beginner aquarist as the Red Snakehead.

African Snakehead

They are called Parachanna Obscura scientifically. They usually resemble the Splendid snakehead in colour as well shape but can be distinguished by their prominent as well as long tubular nostrils. They can reach up to 45cm or 18 in. The parameters of the water should be similar to the Splendid Snakehead. Besides this, these species are considered as more docile species.

Intentional Introductions

Humans are the reason who have been introducing snakeheads for over 100 years into the non - native areas. They are considered valuable food in Asia or Africa and kept in aquaculture as well. Some of the examples of the introduction of snakeheads are given below:

• Around the end of the 19th century, a species of snakehead or snake fish that was introduced in Madagascar and Hawaii, known as Channa maculata, can be found there today as well.

• Channa striata, one of the species of snakehead, was introduced in the latter half of the 20th century into the islands present east of the Wallace line whereas in Fiji it was failed. 

• Channa Asiatica was introduced to Taiwan as well as South Japan and it was native to China whereas its reason for introduction is not known.

• Channa argus which was the native of the Amur river of China was introduced to Countries of Central Asia such as Kazakhstan, Turkmenistan as well as Uzbekistan. It was also introduced to Japan around 100 years ago because of the fishery's motivation. Besides these, it also has been introduced to Czechoslovakia but it failed in 1960.

Invasive Spread

They have been introduced in Central Asia and other regions such as Eastern Europe, Japan, Kazakhstan, and the United States. These species grow and reproduce very quickly and also have the potential to threaten the native species and thus be considered as ecological threats. The largest invasive species of this fish is found in the Potomac River drainage of the US. Snakehead was found for the first time in 2002 in the US in a pond in Maryland which was being removed with the usage of rotenone which is a fish poison but again it was found in 2004 in Potomac and have been established there ever since.

According to the United States Environmental Protection Agency, snakeheads have also been spotted in California, Delaware, Florida, Georgia, Hawaii, Maine, Maryland, Massachusetts, Virginia, as well as Rhode Island. Besides these, they have also been spotted in New York State according to the Department of Environmental Conservation of the state.  In 2019, snakehead was caught by a fisherman in Georgia which was the first sighting of this fish in that state. Various laws of the state say that they would be killed if found and environmentalists are also concerned about their spread up to the Great Lakes which can cause serious issues to the sensitive ecosystems. Several efforts are being taken in order to limit their spread as well as to eradicate them with the help of various programs. Awards are given by the state of Maryland to those who catch the big fishes and whenever these fish are caught, serious measures are taken in order to eradicate them such as killing them & other possible measures. The import of this fish is banned in the entire country and they are considered illegal to own whereas it is also illegal to ship as well move them across the states according to the Lacey Act. 

World Record

According to the International Game Fish Association, a 7.9 kg snakehead was caught on June 1, 2013, by a resident in Virginia at the junction of Potomac River and Aquia Creek in the United States of America which became a world record. The previous record was 57 g which had been caught in Kagawa, Japan in 2004.   

Popular Culture

Due to intentionally or accidentally introduction or release of snake fish in the non-native areas, they are considered as aggressive species or frankenfish or monster fish and these names have become part of the culture now. They have been featured in some of the TV Shows as well such as The Sopranos, CSI: NY episode "Sangre por Sangre", The Office orCentral Park episode "A Fish Called Snakehead". They have also been featured in Sci-fi pictures namely Snakehead Terror, Frankenfish, as well as, Swarm of the Snakehead. Jeremy Wade in the River Monsters series of Animal Planet shows its dramatization, "the fish from hell" by stalking a baby. He shows how it is possible for snakeheads to live outside the water and their ability to move on land. In Bless the Hart's, in the 8th episode of the 2nd season, this fish in North Carolina was shown as a wanted fish and Wade was also affected by its slime and started hallucinating.

Conclusion

Thus, to wrap up the discussion about the snakehead, we can conclude that they are native to Asia and Africa but can be found in other parts of the world and considered as invasive species which cause a threat to the ecosystem. There are various species of snakeheads and they are also considered good food as well. They have elongated bodies and have the ability to breathe air through gills and can move short distances on the land as well. They can be grown up to 3 feet or more and can be as small as a few centimetres. The large species can be aggressive and need to be taken care of while handling them.

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