How Many Species of Snakehead Fishes are in the USA? by Don Orth

The summer of 2002 was the summer of the snakehead — the first exposure with these exotic fishes for many of us.  It began with the first appearance of the Northern Snakehead Channa argus in a small pond in Crofton, Maryland.   Snakehead fishes are air-breathing freshwater fishes in the family Channidae. The genus Channa includes snakeheads of Asia, Malaysia, and Indonesia, and the genus Parachanna occur in Africa. In their native range, they are important food fish. Elsewhere, snakeheads are popular in live food fish and aquarium trades and many species are cultured for food.  Recently sport fishing for snakeheads has grown in popularity. After the establishment of the Northern Snakehead in the Potomac River, it spread to other tributaries of Chesapeake Bay and scientists are concerned about its potential to spread into all the Great Lakes except Superior (Kramer et al. 2017; Love and Newhard 2018).  In all habitats it colonizes, scientists will need to evaluate its potential to threaten native fishes, the recreational fishing industry, and aquatic ecosystems, all of which will cost time and money.

Top Ten Little Known Facts about the Snakehead Fish. 

(The Late Show with David Letterman, Dolin 2003).

10.       The fish is 50 percent snake, 50 percent head. 

9.         Mortal enemy is the fishhead snake.

8.         High-protein diet of fish and frogs means slim look for summer. 

7.         They love kids.

6.         Bush promised to find and catch them…of course we’ve heard that before. 

5.         Fans of the snakehead fish are known as snakehead-heads.

4.         Available for a limited time at participating Red Lobsters. 

3.         It’s very popular with lawyers, am I right people?

2.         Developed by the government to distract people from the whole Cheney-Halliburton thing. 

1.         It’s the result of a drunken genetic engineer and a dare. 

Many initial fears were overblown or laughed off by comedians who managed to pass on misinformation about the snakehead.   This infographic in The Onion from 2002 joked about the  snakehead signing movie deals left and right.  Snakehead fish played a feature role in four movies, including Snakehead Swamp, Frankenfish, Snakehead Terror, and Swarm of the Snakehead. But the movie hype only distracted us from learning more about the potential for the snakehead to cause harm. 

Invasive species are serious concerns as our global society facilitates transcontinental introductions.  An invasive species is "an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health" as per Executive Order 13112: Section1. Definitions. Defining harm is the most difficult prerequisite to devising management interventions. Charles Elton introduced the militaristic "invasion" metaphor to describe exotic plants and animals in the 1950s and we’re often stuck with a Mission Impossible situation. Julian Olden, Professor in the School of Aquatic and Fishery Sciences at the University of Washington, refers to this approach as the "guilty even when proven innocent."  

The snakehead family of fishes have been federally regulated since 2002 when they were listed as injurious wildlife under the Federal Lacey Act (18 USC 42), which makes it illegal to import injurious wildlife into the United States or transport between the listed jurisdictions in the shipment clause (the continental United States, the District of Columbia, Hawaii, the Commonwealth of Puerto Rico, and any possession of the United States) without a permit. An injurious wildlife listing would not prohibit intrastate transport or possession of that species within a State where those activities are not prohibited by the State. See also: Injurious Wildlife: A Summary of the Injurious Provisions of the Lacey Act. 

The first step in determining harm is to map out the occurrence and consider where and what other species it might influence.  But this is not a simple step because there are five, not one, species of snakehead fish known to occur in USA (Benson 2019).

Blotched Snakehead Channa maculata is native to southern China and Vietnam.  It was the first snakehead introduced to the island of O’ahu, Hawaii in the late 1800s.  It became established there in ditches, ponds, and reservoirs.  

from USGS

Giant Snakehead Channa micropeltes is tropical-subtropical species native to India, southeast Asia, including the peninsular Malaysia.  It has been collected in six states presumably due to aquarium releases (Benson 2019). 

Giant Snakehead Source

Giant Snakehead juvenile. Source

Northern Snakehead Channa argus is a temperate species native to the Korean peninsula and eastern rivers of China and Russia.  Northern Snakehead have been collected from 13 states and the District of Columbia (Benson 2019).   Northern Snakehead has established populations from Arkansas, Virginia, Maryland, Delaware, New Jersey, and New York. History of introductions of the Northern Snakehead is chronicled in Benson (2019).  Populations originated from escapees from fish culture ponds (banned in 2002), live food markets, and human assisted introductions.

Northern Snakehead.  Illustration by Susan Trammell. Source

Chevron Snakehead Channa striata is a a warm temperate species native to Pakistan and parts of southeast Asia.  It was introduced into Hawaii as broodstock for commercial aquaculture. 

Chevron Snakehead.  USGS

Bullseye Snakehead Channa marulius is native to tropical and warm temperate regions of southeast Asia, southern China, and Pakistan.  The Bullseye Snakehead has been established in southern Florida since at least 2000, but has not colonized Everglades National Park or Big Cypress Natural Preserve.  

Bullseye Snakehead.  (c) Michigan Science Art.  Source.

It helps that we know more about the distribution of these five snakehead fishes.  Context is everything.   Before snakehead fish were banned for import, live snakeheads were common in live-food markets where they could easily be released to create fisheries or for prayer release ceremonies. The Buddhist practice known as ‘live release’, ‘fang sheng’, ‘mercy release’, and ‘prayer animal release’, entails the release into the wild of captive animals and particularly those destined for slaughter. However, this ancient practice would release animals to their native habitats (Everard et al. 2019).   

Given the multiple species and settings for introduction, we need to treat each case and context according to best information regarding harm and feasible management policies (SPDC 2014; Orth 2019).  To develop and enact sensible policies, it is crucial to consider two philosophical questions: (1) What exactly makes a species native or exotic, and (2) What values are at stake? (Woods and Moriarty 2001). Humans are important vectors so the solution to widespread dispersal must focus on human behavior. Importing live snakeheads is prohibited as is their interstate transport.  Maryland and Virginia prohibit possession of live snakeheads.  Penalties for transporting live Snakehead should be continued and communicated widely.  Fishing and bow fishing have potential to reduce local abundance of Northern Snakehead in Potomac tributaries.   Whether we can eat our way out of the snakehead abundance is yet to be seen, though plenty of recipes will work for this tasty fish.    

Snakehead Cakes prepared by Alewife Restaurant, Baltimore.  Photo by D.J. Orth.

References

Benson, A.J. 2019. Snakehead fishes (Channa spp.) in the USA.  Pages 000-000 in D. Chapman and J. Odenkirk, editors.  First International Snakehead Symposium, American Fisheries Society Symposium 89.  Bethesda, Maryland.  

Dolin, E.J. 2003.  Snakehead: Fish out of water.  Smithsonian Books, Washington, D.C.

Everard, M., A.C. Pinder, R. Raghavan, and G. Kataria. 2019.  Are well-intended Buddhist practices an under-appreciated threat to global aquatic biodiversity?  Aquatic Conservation Marine and Freshwater Ecosystems 29:136-141. 

Kramer, A. M., G. Annis, M. E. Wittmann, W. L. Chadderton, E. S. Rutherford, D. M. Lodge, L. Mason, D. Beletsky, C. Riseng, and J. M. Drake. 2017. Suitability of Laurentian Great Lakes for invasive species based on global species distribution models and local habitat. Ecosphere 8(7):e01883.

Love, J.W., and J.J. Newhard. 2018. Expansion of Northern Snakehead in the Chesapeake Bay watershed. Transactions of the American Fisheries Society 147:342-349.

Orth, D.J. 2019.  Socrates opens a Pandora’s Box of Northern Snakehead issues.   Pages 000-000 in D. Chapman and J. Odenkirk, editors. First International Snakehead Symposium, American Fisheries Society Symposium 89.  Bethesda, Maryland.  

Snakehead Plan Development Committee (SPDC). 2014. Draft National Control and Management Plan for Members of the Snakehead Family (Channidae).Submitted to the Aquatic Nuisance Species Task Force.  https://www.anstaskforce.gov/Species%20plans/SnakeheadPlanFinal_5-22-14.pdf Accessed July 5, 2018.

Woods, M., and P. Moriarty. 2001. Strangers in a strange land: The problem of exotic species. Environmental Values10:163-191.