Northern snakehead

The northern snakehead (Channa argus) 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. 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, Missouri, and Mississippi.

Appearance

thumb|left|Head of a northern snakehead

The distinguishing features of a northern snakehead include a long dorsal fin with 49–50 rays,

Behavior

The northern snakehead is a freshwater fish and cannot tolerate salinity in excess of 10 parts per million. This unusual respiratory system allows it to live outside of water for several days. As an amphibious fish, it can wriggle its way between bodies of water or survive being transported by humans. Only young members of this species (not adults) may be able to move overland for short distances using wriggling motions.

Subspecies

Two subspecies have been recognized:

C. a. argus <small>(Cantor, 1842)</small> (Northern snakehead) China and Korea
C. a. warpachowskii <small>Berg, 1909</small> (Amur snakehead) eastern Russia.

As an invasive species

In its native Asia, the snakehead fish is considered to be an important food fish and for this reason they have been exported to many other regions around the world. They were first introduced to Japan from mainland Asia in the early 1900s, where they have since become a sport fish. The USSR experimented with aquaculture of snakeheads during the mid 20th century in both Europe and Central Asia. In the United States, snakeheads were only cultured in Arkansas, but have managed to establish populations there and several states in the Mid-Atlantic.

Japan

Snakeheads of Korean stock were first introduced to Japan in the 1920s, and since then have spread to about every suitable body of water on the Japanese mainland.

Europe

During the Cold War, the USSR imported several different species of fish from eastern Eurasia into Europe for new prospects in aquaculture. Among these fish was the northern snakehead, which came from the Amur River basin and were stocked in various ponds of the Moscow region starting in 1949. These initial experiments were successful and it was recommended that snakehead be stocked into various other waterbodies. However, only one shipment to Czechoslovakia was ever made in 1955, and nothing else after. The snakehead was also introduced to the Volga Delta and various ponds in Yekaterinburg, but are presumed to have failed due to no reports since then.

While the snakeheads were reported to have been breeding in Moscow in the 1950s, they have since disappeared. There are no known populations in Europe in this moment.

In the European Union, it is included in the list of invasive alien species of Union concern and hence cannot be imported, bred, transported, commercialized, or intentionally released into the environment in any of its member states.

Central Asia

The snakehead has managed to establish themselves in the countries of Kazakhstan, Turkmenistan, and Uzbekistan, all of which used to be part of the former Soviet Union. More specifically, they are known to be in the Amu Darya, Syr Darya, and Kashka-Darya since the 1960s due to both accidental and intentional releases. Since then, snakeheads have also been introduced to the Sarysu River, Talas River, and Chu River. They have become an important commercial fish in the region, with around 10 metric tons being harvested from just the Talas in 1989.

United States

The fish first appeared in U.S. news when an alert fisherman discovered one in a Crofton, Maryland, pond in the summer of 2002. The northern snakehead was considered a threat to the Chesapeake Bay watershed, and wary officials took action by draining the pond in an attempt to destroy the species. The action was successful, and two adults and over 100 juvenile fish were found and destroyed. A man admitted having released two adults, which he had purchased from a New York City market, into the pond.thumb|Northern snakehead in shallow water

When the northern snakehead was found in Crofton, the piscicide rotenone was added to the three adjacent ponds.

In 2004, 19 northern snakeheads were captured in the Potomac River, and they were later confirmed to have become established (i.e., they were breeding). They are somewhat limited to that stretch of the river and its local tributaries, upstream by the Great Falls and downstream by the salinity of the Chesapeake Bay. Northern snakeheads continue to be caught in the river as of 2022.

The northern snakehead has been found in three counties of Florida, and may already be established there. Apparently unestablished specimens have been found in Flushing Meadows–Corona Park in New York City, two ponds in Philadelphia, Pennsylvania,

On 1 June 2013, Caleb Newton, a resident of Spotsylvania County, Virginia, caught a northern snakehead from the junction of Aquia Creek and the Potomac River, beating the previous world record of caught in 2004, in Miki, Kagawa Prefecture, Japan.

thumb|A captured northern snakehead.

In late 2013, authorities in Maryland and Virginia were counting snakeheads in the Chesapeake Bay to better understand the impact of the introduction of the fish to the local ecosystem. The Commonwealth of Virginia has criminalized the "introduc[tion]" of snakeheads into the state without specific authorization, although the relevant statute does not explain whether mere importation is sufficient to constitute "introduc[tion] into the Commonwealth" or whether instead release into the environment is required.

On May 20, 2014, Luis Aragon of Triangle, Virginia, caught a northern snakehead, which was officially listed as the biggest ever caught on rod and reel, according to the International Game Fish Association.

On the night of May 24, 2018, Andrew "Andy" Fox of Mechanicsville, Maryland, shot a northern snakehead with a bow and arrow, which was officially listed as the biggest ever shot according to the Maryland Department of Natural Resources. The record-breaking northern snakehead weighed , with a length of . The snakehead was shot in Mattawoman Creek in Charles County, Maryland, near Indian Head.

In October 2019, a number of northern snakeheads were found in a pond on private property in Gwinnett County, Georgia.

In August 2021, a snakehead weighing was caught in a reservoir in Canton, Massachusetts.

In 2024 a snakehead was confirmed at the Duck Creek Conservation Area in southeast Missouri.

In August 2025 multiple snakehead have been caught in the Crosswicks Creek, New Egypt, New Jersey with a live sample being confirmed by the NJ DEP.

A new concern is that this fish's spreading is getting close to the Great Lakes, which it may enter and disrupt that ecosystem.

Canada

In 2012, a suspected northern snakehead was found in a pond in Burnaby, British Columbia, but further study revealed that it had been released three months or less before its capture and that it was a blotched snakehead or perhaps a hybrid involving that species. Before its exact identity was revealed, the government of British Columbia introduced legislation banning the possession of snakeheads and several other potentially invasive species.

In traditional culture

Northern snakeheads are respected among some Chinese fishermen for their virtue, as parent snakefish are known to sacrifice themselves to protect their young. The young fish are said to rush to feed upon their mother after she gives birth and is temporarily unable to catch prey.

References

External links

InvadingSpecies.com
Recognizing Northern Snakehead
Northern Snakehead
Species Profile- Northern Snakehead (Channa argus), National Invasive Species Information Center, United States National Agricultural Library. Lists general information and resources for Northern Snakehead.