[Federal Register: October 4, 2002 (Volume 67, Number 193)]
[Rules and Regulations]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 16
Injurious Wildlife Species; Snakeheads (family Channidae)
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Final rule.
SUMMARY: The U.S. Fish and Wildlife Service adds all species of
snakehead fishes in the Channidae family to the list of injurious fish,
mollusks, and crustaceans. By this action, the Service prohibits the
importation into or transportation between the continental United
States, the District of Columbia, Hawaii, the Commonwealth of Puerto
Rico, or any territory or possession of the United States. The best
available information indicates that this action is necessary to
protect wildlife and wildlife resources from the purposeful or
accidental introduction and subsequent establishment of snakehead
populations in ecosystems of the United States. Live snakehead fishes
or viable eggs can be imported only by permit for scientific, medical,
educational, or zoological purposes, or without a permit by Federal
agencies solely for their own use; permits will also be required for
the interstate transportation of live snakeheads or viable eggs
currently held in the United States, for scientific, medical,
educational, or zoological purposes. This final rule becomes effective
immediately upon publication.
DATES: This rule is effective October 4, 2002.
FOR FURTHER INFORMATION CONTACT: Kari Duncan, Division of Environmental
Quality, Branch of Invasive Species at (703) 358-2464 or kari--
Summary of Actions Taken and Comments
The Fish and Wildlife Service published a proposed rule in the July
26, 2002 (67 FR 48855), Federal Register based upon information we
obtained indicating that snakehead fishes are injurious to the wildlife
and wildlife resources of the United States. The proposed rule invited
comments for 30 days ending August 26, 2002. We received 453 written
comments during this period. Of those 453 comments, 386 were
nonrelevant or nonsignificant, one offered editorial suggestions on the
proposed rule, 32 were opposed to adding snakeheads to the list of
injurious fishes, and 34 stated their support for the proposed rule. Of
the 386 nonrelevant or nonsignificant comments, 353 were electronic
messages that were generated erroneously, 13 were electronic messages
pertaining to investment scams, 8 were electronic messages pertaining
to advertising, one comment offered a resume for employment
opportunities, 2 were unknown, 2 offered suggestions/opinions on
treating the ponds in Crofton, Maryland, and 7 provided information on
sightings of snakeheads. Of the 67 comments that were considered
relevant and significant, one came from a Federal agency, 12 from
private organizations, 8 from State agencies, and 46 from private
We reviewed all comments received for substantive issues and new
information regarding the injurious nature of snakehead fishes. Similar
comments were grouped into issues; these issues and our responses to
each are presented below:
Issue 1: One respondent stated that some readers may not understand
that snakeheads are fishes until it's stated later in the proposed
rule. The respondent suggested clarifying the rule by using the terms
``snakehead fish'' or ``snakehead fishes'' either early in the rule or
throughout the rule.
Response: The Service agrees with the respondent's comments on this
issue. The suggested changes to improve clarification are used in the
Issue 2: Twenty-one respondents requested that we not list the
entire family of snakehead fishes (Channidae) as injurious, but that we
list those species (up to five species) that are large and cold
tolerant. The respondents stated that the small, temperature-sensitive
species used in the aquarium hobby would not pose a threat in most of
the United States because, if released, they would not survive the cold
Response: We acknowledge that five of the 28 species recognized in
the Channidae family at this time are considered large, approximately 6
are considered dwarf species, and the remaining species are considered
medium-size snakehead fishes. As we presented in the proposed rule, the
family Channidae contains 9 species that are strictly tropical, 4 can
be considered tropical to subtropical, one is subtropical, 12 can
tolerate tropical or subtropical to warm temperate conditions, one is
warm temperate, and one is warm temperate to cold temperate.
The tropical species would survive in the warmest waters such as
extreme southern Florida, perhaps parts of southern California, Hawaii,
and certain thermal spring systems and their outflows in the American
west. The tropical to subtropical species would have a similar
potential range of distribution as for tropical species but with a
greater likelihood of survival during cold winters and more northward
limits. The tropical or subtropical to warm temperate species could
survive in most southern States. The warm temperate, and warm temperate
to cold temperate, species could survive in most areas of the United
Although the tropical to subtropical species of snakehead fishes
are not likely to become established in the northern waters of the
United States, all of the Channidae species, including the dwarf
species, are aggressive and highly predatory. Should a species of
snakehead fishes be accidentally or intentionally released into U.S.
waters, the 131 taxa of threatened and endangered amphibians, fishes,
and crustaceans could face additional threats. Additionally, because
snakehead fishes are morphologically very similar, it would be very
difficult for biologists, wildlife inspectors at entry ports, and law
enforcement agents to differentiate among species of snakeheads.
Based upon the aggressive, predatory nature of all species of
snakehead fishes, the fact that one or more species could become
established in most waters of the United States, and the fact that it
is very difficult to differentiate among the species of snakeheads, the
Fish and Wildlife Service has determined that all 28 of the currently
recognized species of snakehead fishes in the Channidae family should
be listed as injurious fishes under the Lacey Act.
Issue 3: Six respondents indicated that most hobbyists and fish
keepers are responsible and know that releasing exotic species into the
environment is dangerous to the environment. The respondents indicated
that the responsible hobbyists should not be punished and all species
of snakehead fishes should not be listed as injurious. Additionally,
most of these respondents stated that an educational campaign should be
initiated to explain the hazards of releasing exotic species into the
environment and encourage the proper disposition of unwanted pets.
Response: The Service appreciates that most hobbyists and fish
keepers are responsible and properly dispose of unwanted pets. It is to
the tremendous credit of hobbyists that snakehead fishes
have been imported into the United States and only a small number have
been found in the wild. This rule is not intended to punish hobbyists;
it is based upon the scientific evidence that indicates that snakehead
fishes are aggressive and highly predatory and therefore threaten the
wildlife and wildlife resources of the United States. It is important
to note that individuals or organizations who possessed snakeheads
prior to the injurious wildlife listing in States where possession of
snakeheads is legal will be able to continue to possess them; however,
they will be prohibited from transporting them across State lines.
The Fish and Wildlife Service has initiated a national public
awareness campaign known as Stop Aquatic Hitchhikers! This campaign
targets aquatic recreation users to raise their awareness about the
growing aquatic invasive species problem and to encourage them to
become part of the solution in preventing the spread of harmful,
nonnative species. While aquatic recreation users may not be
responsible for bringing these species into the country, they may
inadvertently transport them overland. The Service is working with
State fish and wildlife agencies, conservation organizations, and the
fishing and boating industries to address this issue. The campaign has
a supporting web site with the address: http://
The Service is considering the development of a new campaign
similar to Stop Aquatic Hitchhikers! that would target aquarium
hobbyists. This campaign would be conducted in conjunction with the Pet
Industry Joint Advisory Council, the largest trade association in the
United States representing the pet industry in Washington, DC, and it
would focus on raising awareness about aquatic invasive species, and
encouraging aquarium hobbyists to adopt preventive actions to avoid
having unwanted aquarium fish and plant species become part of our
environment. The campaign would be a multi-layered, voluntary effort,
and would encourage aquarium species importers, wholesalers, retailers
and consumers to focus on how the aquarium industry is a responsible
economic sector that collectively values the environment and seeks to
protect it while simultaneously enjoying the benefits of the aquarium
Issue 4: Two respondents stated that they are opposed to the
injurious wildlife listing because snakehead fishes are valuable food
Response: The Service recognizes the value of snakehead fishes as a
food source, just as we recognize their value to hobbyists. However, as
stated above, the decision to list the Channidae family of snakehead
fishes is based upon scientific data on the hazards that these fishes
would present to the wildlife and wildlife resources of the United
States. Dead or frozen snakehead fishes can continue to be imported and
transported as an alternative to importing live snakeheads.
Issue 5: Two respondents stated that they consider the injurious
wildlife listing of snakehead fishes to be racist against the Asian
American community because it would prohibit the use of a valuable food
source and protect the sport activity of European Americans.
Additionally, the respondents indicated that the Service should consult
with the Asian American community and that we should consider
snakeheads as an economic resource and not a threat.
Response: The decision to list snakehead fishes as injurious under
the Lacey Act is based solely on the biological characteristics of the
fishes and the need to protect our native wildlife and wildlife
resources, and is in no way based upon race or ethnicity, or preserving
recreational opportunities for certain sectors of the population. We
have substantial scientific data that describe the harm that snakehead
fishes cause when introduced outside of their native range and are
likely to cause if released into U.S. waters.
According to our Law Enforcement data, 372 individuals and 892
kilograms of snakehead fishes were imported into the United States in
1997; 1,488 individuals and 1,883 kilograms were imported in 1998;
6,044 individuals and 8,512 kilograms were imported in 1999; 8,650
individuals and 9,240 kilograms were imported in 2000; and 20,547
individuals were imported in 2001. We do not have information on how
many of those imports contained young fishes destined for the aquarium
trade and how many were larger individuals destined to be sold as live
food fish. While the importations did increase between 1997 and 2001,
the importation of snakehead fishes into the contiguous United States
does not appear to represent a significant portion of live fish
imports. We suggest that all persons who previously used live
snakeheads as a food fish consider the use of dead or frozen fish as an
Issue 6: Two respondents indicated that the proposed listing of
snakehead fishes was based more on hype than fact, and is an
overreaction to media attention.
Response: As a result of the discovery of the bullseye snakeheads
in south Florida, the U.S. Geological Survey and the Service began
evaluating the risks associated with snakehead fishes in 2001.
Consequently, the injurious wildlife listing was being developed within
the Service before the recent media attention.
Outside of what is published in our official press releases, the
Service has no control over what is published in the media. We agree
that some of the facts have been exaggerated, and we have taken
measures to correct misinformation that has appeared in the media.
Issue 7: Thirteen respondents stated that snakehead fishes threaten
ecological harmony, present major risks to ecosystems and aquatic
communities, and could eliminate some of our threatened and endangered
species that are restricted in distribution. The respondents also
stated that the United States has a well-documented history of adverse
consequences to native species due to the introduction of other
Response: The Service agrees with the respondents' comments on
these issues. The biological characteristics of snakehead fishes and
their potential to be injurious to the wildlife and wildlife resources
of the United States is the basis for our decision to add snakeheads to
the list of injurious fishes under the Lacey Act.
Issue 8: Two respondents stated that the fines are too lenient
compared to the potential ecological devastation caused by the
potential establishment of snakeheads.
Response: The Secretary of the Interior has the authority under the
Lacey Act to add species to the injurious wildlife list, but the
Secretary does not have the authority to change the penalties. The
penalties are established by statute and can be changed by an act of
Issue 9: Three respondents stated that the prohibition on
importation and interstate transportation of snakehead fishes would not
significantly impact the aquarium industry. They also stated that the
humane disposition of snakeheads will be encouraged.
Response: The Service is pleased that this action will not result
in significant financial losses to aquarium fish producers,
wholesalers, and retailers. We are also encouraged that the respondents
are willing to proactively promote the humane disposal of the fishes,
thereby reducing the risk that they would be introduced into the
Issue 10: Three respondents stated that they are opposed to listing
the family Channidae by simply referring to ``Channidae'' because the
taxonomy is not clear and not all people are
conversant with scientific names. The respondents suggested we revise
50 CFR 16.13 to resemble a list instead of a paragraph, and that we
include the genus, species, and common names of all currently
recognized snakehead species, as well as the family name.
Response: We have accepted this suggestion and made the changes in
this rule. We have also included synonyms for the Channa and Parachanna
Issue 11: One respondent expressed concern that permits for
importation and interstate transportation can be issued for medical
purposes under the Lacey Act. The respondent indicated that permits
should be granted only to accredited medical institutions.
Response: As described in 50 CFR 16.22, the Director of the Fish
and Wildlife Service may issue permits for the importation and
interstate transportation of injurious species only for scientific,
medical, educational, or zoological purposes. Persons or institutions
wishing to apply for a permit must meet the application requirements,
additional permit conditions, and issuance criteria as set forth in 50
CFR 16.22. Permits are issued only to legitimate individuals and/or
institutions for medical research, scientific, zoological, or
Description of the Final Rule
The regulations contained in 50 CFR part 16 implement the Lacey Act
(18 U.S.C. 42) as amended. Under the terms of that law, the Secretary
of the Interior is authorized to prohibit by regulation certain
activities involving wild mammals, wild birds, fish (including mollusks
and crustaceans), amphibians, reptiles, and the offspring or eggs of
any of the foregoing that are injurious to human beings, to the
interests of agriculture, horticulture, or forestry, or to the wildlife
or wildlife resources of the United States. The lists of injurious
wildlife species are at 50 CFR 16.11 to 16.15. By adding snakehead
fishes to the list of injurious wildlife, their importation into, and
transportation between, States, the District of Columbia, the
Commonwealth of Puerto Rico, or any territory or possession of the
United States by any means whatsoever is prohibited, except by permit
for zoological, educational, medical, or scientific purposes (in
accordance with permit regulations at 50 CFR 16.22), or by Federal
agencies without a permit solely for their own use, upon filing a
written declaration with the District Director of Customs and the U.S.
Fish and Wildlife Service Inspector at the port of entry. No live
snakehead fish, progeny thereof, or viable eggs imported or transported
under a permit may be sold, donated, traded, loaned, or transferred to
any other person or institution unless such person or institution has a
permit issued by the Director of the U.S. Fish and Wildlife Service.
The interstate transportation of any live snakehead fish or viable eggs
currently held in the United States for any purpose is prohibited
without a permit.
Two genera of snakehead fishes are currently recognized in the
family Channidae. They are Channa (snakehead fishes of Asia, Malaysia,
and Indonesia) and Parachanna (African snakeheads). Synonyms include
Bostrychoides, Ophicephalus and its misspelled form Ophiocephalus, and
Parophiocephalus. Although 86 species and 4 subspecies have been
described (Eschmeyer, 1998), current taxonomy is in flux with
approximately 28 species recognized as valid (Musikasinthorn, 2001;
Table 1). Because their morphology is very similar, it is very
difficult to differentiate among species of snakeheads. Juvenile and
adult color patterns are often quite different (Day, 1875; Lee and Ng,
1991, 1994), and some are quite variable in size and color, and may
represent species complexes. A taxonomic revision of the family,
expected to be published within the next two years, will likely result
in additional species being recognized as valid and perhaps new species
Table 1.--Currently Recognized Species of the Family Channidae (After
Musikasinthorn, 2000, 2001).
Channa amphibeus (McClelland, 1845)--no common name known.
Channa argus (Cantor, 1842)--northern snakehead.
Channa asiatica (Linnaeus, 1758)--Chinese snakehead.
Channa aurantimaculata Musikasinthorn, 2000--no English common name;
naga-cheng (Assam, India).
Channa bankanensis (Bleeker, 1852)--Bangka snakehead.
Channa baramensis (Steindachner, 1901)--Baram snakehead.
Channa barca (Hamilton, 1822)--barca snakehead.
Channa bleheri Vierke, 1991--rainbow snakehead.
Channa cyanospilos (Bleeker, 1853)--bluespotted snakehead.
Channa gachua (Hamilton, 1822)--dwarf snakehead.
Channa harcourtbutleri (Annandale, 1918)--Inle snakehead.
Channa lucius (Cuvier, 1831)--splendid snakehead.
Channa maculata (Lacepede, 1802)--blotched snakehead.
Channa marulius (Hamilton, 1822)--bullseye snakehead.
Channa maruloides (Bleeker, 1851)--emperor snakehead.
Channa melanoptera (Bleeker, 1855)--no common name known.
Channa melasoma (Bleeker, 1851)--black snakehead.
Channa micropeltes (Cuvier, 1831)--giant snakehead.
Channa nox (Zhang, Musikasinthorn, and Watanabe, 2002)--no English
Channa orientalis Schneider, 1801--Ceylon snakehead.
Channa panaw Musikasinthorn, 1998--no English common name; ng panaw
Channa pleurophthalmus (Bleeker, 1851)--ocellated snakehead.
Channa punctata (Bloch, 1793)--spotted snakehead.
Channa stewartii (Playfair, 1867)--golden snakehead.
Channa striata (Bloch, 1797)--chevron snakehead.
Parachanna africana (Steindachner, 1879)--Niger snakehead.
Parachanna insignis (Sauvage, 1884)--Congo snakehead.
Parachanna obscura (Gunther, 1861)--African snakehead.
Snakehead fishes have distinctive morphological features as
follows: Long, almost cylindrical body; long dorsal and anal fins, and
all fins supported only by rays; most with large scales on head,
somewhat similar to the large epidermal scales on the heads of snakes
(hence the common name, snakeheads); eyes dorsolateral (back and side)
and located on the anterior portion of the head; tubular, anterior
nostrils; pectoral and caudal fin margins rounded; large mouth with
protruding lower jaw; lower jaw always toothed, and prevomer and
palatines often toothed; some lower jaw teeth canine-like, and canines
present or absent on prevomer and palatines; most species with pelvic
fins present; and ventral aorta typically divided into two portions,
one serving the gills and the other the suprabranchial (above the
gills) chambers. Suprabranchial chambers of Channa are non-labyrinthic
(complex system of paths/tunnels), and made up of two plates, one
formed by the first epibranchial (above the gills), the second from the
hyomandibular; those of Parachanna consist of a single cavity with
elements from the epibranchial of the first gill arch and hyomandibular
Two larger snakehead species, Channa marulius and C. maruloides,
superficially resemble the native bowfin, Amia calva, in that all three
are elongated fishes, have long dorsal fins, tubular nostrils, and an
ocellus (eyespot) at the base of the upper portion of the caudal fin.
The bowfin, however, has its pelvic fins in a more abdominal rather
than thoracic or anterior-abdominal position, and the anal fin is not
elongated. Moreover, the bowfin does not have a rosette (circular
arrangement) of enlarged scales on top of the head.
Species and species complexes of the genus Channa are native from
southeastern Iran and eastern Afghanistan eastward through Pakistan,
India, southern Nepal, Bangladesh, Myanmar (Burma), Thailand, Laos,
Malaysia, Sumatra, Indonesia, and China northward into Siberia. Of the
currently recognized 25 species of Channa, 9 species and
representatives of 4 species complexes occur in peninsular Malaysia,
Sumatra, and/or Indonesia. Of the same 25 species, 16 species and
members of 5 species complexes are tropical to subtropical; members of
three species complexes are temperate; and one species is temperate to
boreal and can live beneath ice in the northern portion of its range.
The three species of Parachanna are native to Africa and are tropical.
Snakeheads are considered as non-ostariophysan primary freshwater
fishes (Mirza, 1975, 1995), meaning they have little or no tolerance
for seawater. Habitat preferences vary by species or species complex,
with a majority occurring in streams and rivers. Others occur in
swamps, rice paddies, ponds, and ditches. All can tolerate hypoxic (low
oxygen) conditions because they are airbreathers from late juvenile
stages. Where known, pH range varies by species with one (Channa
bankanensis) preferring highly acidic (pH 2.8-3.8) waters. At least
three species are tolerant of a wide pH range; C. gachua, C. punctata,
and C. striata survived for 72 hours at pH levels ranging from 4.25 to
9.4 (Varma, 1979).
Spawning seasons vary by species. While information on reproductive
biology of many species is lacking, several conclusions can be drawn
from those for which this information is available. Breeding in several
species occurs primarily in summer months (June through August), and in
at least two (the Channa striata species complex and C. punctata),
breeding pairs can be found throughout the year. Some species spawn
twice each year. Okada (1960) reported that female northern snakeheads,
C. argus, are capable of spawning five times per year. There are
several reports that when snakeheads pair, the pair remains monogamous
for a spawning season, perhaps longer, but a pair may not mate for
Snakehead fishes build nests by clearing a generally circular area
in aquatic vegetation, often weaving the removed vegetation around the
centrally cleared area. This results in a vertical column of water
surrounded by vegetation. One species (C. punctata) prepares elaborate
tunnels through vegetation leading into the nest column. At time of
spawning, the male and female move upward into the central region of
the nest column. The male entwines his body around that of the female,
with some species appearing to ``dance'' in the water column as eggs
are released and fertilized (Breder and Rosen, 1966; Ng and Lim, 1990).
Eggs are buoyant, rising to the surface of the nest column, where they
are vigorously guarded by one or both parents. Snakeheads in two
species complexes (C. gachua and C. orientalis) are mouthbrooders, with
the male being the mouthbrooder of fertilized eggs and, later, fry.
Most snakehead fishes, however, are not mouthbrooders, but one or both
parents guard their young vigorously; one species (C. micropeltes)
reportedly attacked and in some instances killed humans who approached
the mass of young (Kottelat, 1993). Thus, parental care, whether by
mouthbrooding or guarding, is a behavioral characteristic of snakehead
fishes. Successful spawning in the absence of vegetation has also been
reported for three species of snakeheads (Parameswaran and Murgesan,
Fecundity and early development: There is limited information on
fecundity (capacity to produce offspring) except for those snakehead
fishes of commercial importance. Nevertheless, that information shows a
pattern that likely applies to the entire family Channidae. Smaller
species, such as Channa gachua and C. orientalis, produce few
o[ouml]cytes or unfertilized ``eggs'' (about 20 when sexual maturity is
first reached and later up to 200; Lee and Ng, 1991, 1994). Both are
considered to be ``species complexes'' and one or both ``species''
contain mouthbrooding adults; low fecundity is a general rule among
mouthbrooding fishes (Breder and Rosen, 1966). Fecundity increases
greatly in larger snakehead species and appears to follow increasing
body length. For example, Quayyum and Quasim (1962) recorded fecundity
ranging from 2,300 to 26,000 o[ouml]cytes for C. striata, increasing in
number with increasing body length. The bullseye snakehead, C.
marulius, the largest species of snakehead, has been reported to
produce approximately 40,000 o[ouml]cytes (Jhingran, 1984). Frank
(1970) reported that the northern snakehead, C. argus, produced
approximately 50,000 o[ouml]cytes. Frank's data came from Nikol'skiy
(1956) who recorded fecundity of 22,000 to 51,000 in northern snakehead
from the Amur basin. Dukravets and Machulin (1978) gave fecundity rates
of 28,600 to a high of 115,000 for northern snakehead (probably from
Yangtze River stock) introduced to the Syr Dar'ya basin of
Turkmenistan/Uzbekistan. They also noted that, although the growth of
northern snakehead is slower than that reported for this species from
the Amur basin, growth rates from both stocks become equal once sexual
maturity is reached.
O[ouml]cytes, when released from the female parent, are small,
ranging from approximately 1 mm to slightly over 2 mm in diameter,
depending on species. Fertilization takes place by the male releasing
milt (sperm) on the o[ouml]cytes (or eggs) as they emerge from the
female. Eggs contain an oil droplet within the yolk mass, which causes
them to rise to the surface. Development time to hatching varies with
water temperature and, to a lesser extent, with the species involved.
For example, hatching occurred in 54 hours at 16-26[deg]C and 30 hours
at 28-33[deg]C in Channa punctata (Khan, 1924). In the northern
snakehead, C. argus, eggs hatch in 28 hours at 31[deg]C, 45 hours at
25[deg]C, and 120 hours at 18[deg]C.
Early life history: In general, newly hatched fry, depending on
species, are about 3.0--3.5 mm in length. Following yolk absorption,
snakehead fry begin feeding on zooplankton. Fry typically remain
together until they reach early juvenile stage, guarded by one or both
adults, or until they can fend for themselves (Lee and Ng, 1994). Late
juveniles of the giant snakehead, Channa micropeltes, school and feed
in packs (Lee and Ng, 1991). Although there are few reports of early
life history except for species of commercial importance, it appears
that, as larval snakeheads mature to early juvenile stages, the diet
changes to small crustaceans and insects, particularly insect larvae.
Presence of phytoplankton, plant material, and detritus in the
digestive system of young snakeheads, as well as adults, appears to
occur from incidental ingestion.
Respiration and overland migrations: Snakeheads are highly evolved
airbreathing teleostean (bony) fishes, and many are capable of overland
migration by wriggling motions (Lee and
Ng, 1991; Berra, 2001). They possess suprabranchial (above the gills)
chambers for aerial respiration, and the ventral aorta is divided into
two portions to permit bimodal (aquatic and aerial) respiration (Das
and Saxena, 1956; Graham, 1997). The suprabranchial chambers become
functional during the juvenile stage of growth (Graham, 1997),
following which some species of snakehead fishes are obligate (limited,
bound to a restricted environment) and others are facultative
(optional, ability to live under varied conditions) airbreathers. In
Channa, the chambers open into the pharynx through inhalent openings.
The chamber lining contains respiratory ``islets'' with vascular
papillae. The chambers can be filled with air or water. In addition, in
C. striata, there are also vascular structures in the mouth and pharynx
that can be utilized for respiration; these, however, can be retracted
into depressions to prevent damage when feeding (Munshi and Hughes,
Some channids, perhaps all, have a circadian rhythm in oxygen
uptake. Channa marulius, for example, showed a peak in oxygen uptake at
night. C. striata and C. gachua peaked in early night hours, and C.
punctata at dusk (Munshi and Hughes, 1992). Munshi and Hughes (1992)
attributed these rhythms to evolution in swamp ecosystems (i.e., the
rhythm is a property of the ecosystem).
It is unknown how many species of snakehead fishes are capable of
overland migrations, but several are known to do so. These migrations
from drying habitats in search of those with water are probably driven
by instinctive behavior. Overland migrations likely apply to those
species whose native range is subject to seasonal dry/wet (or
monsoonal) conditions (encompassing much of western to southeastern
Asia, where a majority of snakehead species exist).
Hypoxic survival: Snakehead fishes are either obligate or
facultative airbreathers. Therefore, survival in hypoxic waters is not
problematic to these fishes. When prevented from access to the surface,
some adult snakeheads will drown due to lack of oxygen (Day, 1868, Lee
and Ng, 1991). Moreover, snakeheads can remain out of water for
considerable periods of time as long as they remain moist. Some
snakeheads, especially Channa striata, can bury themselves in mud
during times of drought (Smith, 1965). They are known to secrete mucus
that helps to reduce desiccation and facilitates cutaneous breathing
(Mittal and Banerji, 1975; Lee and Ng, 1991).
Fishers in Thailand are aware of this habit and, during drought
periods, will slice into the mud until they locate the fish (Smith,
For larger species of snakeheads such as Channa marulius, young are
facultative airbreathers and adults are obligate breathers (Wee, 1982),
but all species are airbreathers.
Lifespan: No specific information on lifespan can be found in the
literature. Nevertheless, one species (C. marulius) is reported to
reach a total length of 1.8 meters in Maharashtra State, India (Talwar
and Jhingran, 1992), indicating a relatively long lifespan. Smaller
snakeheads, such as members of the C. gachua and C. orientalis species
complexes, may not live for more than a few years. Most larger
snakeheads are reported to reach sexual maturity in two years, after
which growth slows but fecundity increases with increasing size.
Feeding habits: There are few studies of feeding habits of
snakeheads. For those species studied, following yolk-sac absorption,
snakehead fry feed mostly on zooplankton. As juveniles, they feed on
insect larvae, small crustaceans, and fry of other fishes (Munshi and
Hughes, 1992). What is universal in reports of adult feeding habits is
that snakeheads are predators with many species showing a preference
for other fishes, although they may also consume crustaceans, frogs,
smaller reptiles, and larger species may sometimes consume birds and
small mammals. Under conditions of food deprivation, snakeheads can
become cannibalistic on their own young. The piscivorous (fish-eating)
nature of snakeheads has led to the use of some species (C. striata and
C. micropeltes in particular) to control tilapia populations in
Associated diseases and parasites: Investigations of diseases and
parasites of snakeheads concentrate on those species of importance in
aquaculture. Bykhovskaya-Pavlovskaya et al. (1964) cited Channa argus
as hosting 18 parasite species (Table 2). Two of the same parasites
listed by Bykhovskaya-Pavlovskaya et al. (1964) were reported from the
digestive tracts of northern snakehead from Kyungpook Province, Korea,
from 115 specimens collected between 1995 and 1997. The trematode
Azygia hwangtsinyi was found in 47% of the samples and the nematode
Pingis sinensis in 73%.
Table 2.--Parasites of northern snakehead, Channa argus (Adapted From Bykhovskaya-Pavolovskaya et al. (1964)
Parasite Group Host issues Other fishes affected
Myxidium ophiocephali.................. Myxosporidia....................... Gall bladder, liver ducts.........
Zschokkella ophiocephalli.............. Myxosporidia....................... Kidney tubules....................
Neomyxobolus ophiocephalus............. Myxosporidia....................... Gill filaments....................
Mysosoma acuta......................... Myxosporidia....................... Gill filaments.................... crucian carp.
Myxobolus cheisini..................... Myxosporidia...................... Gill filaments....................
Henneguya zschokkei?................... Myxosporidia...................... Gills, subcutaneous, musculature.. salmonids (tubercle disease of
Henneguya ophiocephali................. Myxosporidia....................... Gill arches, suprabranchial
Henneguya vovki........................ Myxosporidia....................... Body cavity.......................
Thelohanellus catlae................... Myxosporidia....................... Kidneys...........................
Gyrodactylus ophiocephali.............. Monogenoidea....................... Fins..............................
Polyonchobothrium ophiocephalina....... Cestoidea.......................... Intestine.........................
Cysticercus Gryporhynchus Cestoidea.......................... Gallbladder, intestine............ cyprinids, perches.
Azygia hwangtsi[uuml]i................. Trematoda.......................... Intestine.........................
Clinostomum complanatum................ Trematoda.......................... Body cavity....................... perches.
Pingis sinensis........................ Nematoda........................... Intestine.........................
Paracanthocephalus curtus.............. Acanthocephala..................... Intestine......................... cyprinids, esocids, sleepers, bagrid
Paracanthocephalus tenuirostris........ Acanthocephala..................... Intestine.........................
Lamproglena chinensis.................. Copepoda........................... Gills.............................
Literature on parasites of snakeheads includes numerous
descriptions of new species, not detailed herein, but indicates that
most studies concentrate on cultured fishes such as Channa argus, C.
punctata, and C. striata. The potential threat of these parasites to
native North American fishes has yet to be examined.
A disease that received broad attention is epizootic ulcerative
syndrome (EUS) that causes high mortality in snakeheads, particularly
Channa striata and C. punctata under intensive culture. EUS involves
several pathogens, including motile aeromonad bacteria (e.g., Aeromonas
hydrophila, A. caviae, Pseudomonas fluorescens; Prasad et al., 1998;
Qureshi et al., 1999), a fungus Aphanomyces invadans (considered a
primary pathogen; Mohan et al., 1999; Miles et al., 2001), and perhaps
a rhabdovirus (Kanchanakhan et al., 1999; Lio-Po et al., 2000). Another
bacterium, Aquaspirillum sp., has also been implicated in the disease
(Lio-Po et al., 1998). EUS may have originated in India in the 1980s,
but has since been found in Pakistan, Thailand, and the Philippines
with outbreaks reported from all these areas during the 1990s.
Snakeheads are not the only fishes affected by this disease. It is also
known to occur in airbreathing catfish (Clarias), the bagrid catfish
genus Mystus, two cyprinid genera (Cyprinus and Puntius), mastacembalid
eels (Mastacembalus), and the nandid genus Nandus in India (Mukherjee,
1998). In Thailand, it has been found in giant gourami (Osphronemus
gouramy) and climbing perch (Anabas testudineus) during an outbreak in
1996-1997 (Kanchanakhan et al., 1999).
History of introduction in the United States: Four species of
snakeheads (Channa argus, C. marulius, C. micropeltes, and C. striata)
have been recorded from open waters of the United States (California,
Florida, Hawaii, Maine, Maryland, Massachusetts, and Rhode Island), and
two have become established as reproducing populations. At least 16
States prohibit possession of live snakeheads (Alabama, Arkansas,
California, Colorado, Florida, Georgia, Idaho, Kentucky, Mississippi,
Nevada, North Carolina, Oregon, Pennsylvania, Texas, Utah, and
Washington), and illegal activity, confiscations, citations, or
investigations have occurred in six of those States within the past two
years (Alabama, California, Florida, Kentucky, Texas, and Washington).
Florida: An established population of the bullseye snakehead,
Channa marulius, was discovered in residential lakes and adjoining
canals in Tamarac, Broward County, Florida, in 2001 (Florida Fish and
Wildlife Conservation Commission, 2001). It is unknown how long this
species has occupied these waters, perhaps several years, but both
juveniles and adults have been collected, which indicates reproductive
success. This species is the largest of snakeheads, with adults
commonly reaching lengths of 120-122 cm (Talwar and Jhingran, 1992).
Researchers have reported that in Maharashtra State, India, this
species can reach a length of 1.8 m and a weight of 30 kg (Talwar and
Jhingran, 1992). A length of 30 cm can be reached in one year (Talwar
and Jhingran, 1992). The pathway of the introduction to Florida is
unknown. The species may have escaped from a fish farm (although there
are none known in Tamarac), been purposefully introduced to establish a
food or aquarium fish resource, or they may have been introduced by
aquarists. Tamarac is located just east of Water Conservation Area II,
north of Everglades National Park, and interconnected canal systems
lead into this area. Nevertheless, there are water control structures
on canals leading into Water Conservation Area II that would have to be
open to allow this snakehead access to that area. It is likely that C.
marulius will expand its range in peninsular Florida as its native
range includes tropical to temperate climates. The bullseye snakehead
is considered predacious (Jhingran, 1984; Talwar and Jhingran, 1992),
especially on other fishes (Schmidt, 2001).
The northern snakehead, Channa argus, is also reported from Florida
waters. Two individuals were caught in the St. Johns River below Lake
Harney, Seminole and Volusia counties, in 2000. Unconfirmed reports
indicate three additional individuals having been caught nearby. An
attempt to collect additional specimens by U.S. Geological Survey
(USGS) personnel by electroshocking was unsuccessful, but will be
repeated in 2002. Until reproduction has been confirmed, the species is
considered present but not established. This species is not involved in
the aquarium fish trade, but is sold in live food fish markets as a
food fish. The most likely pathway is introduction of live food fish,
perhaps to establish a local source. The northern snakehead is sold in
live food fish markets and some restaurants in Boston and New York,
where snakeheads are legal. Live C. argus were confiscated in
Washington (100 individuals, alive on ice, destined for the
international district of Seattle), a market in Houston, Texas (Howells
et al., 2002), markets in Miami and Plantation, southeastern Florida,
in 2001, and in Orlando, Florida, in March 2002, all indications of the
availability of this species in States where possession is illegal.
Moreover, a few U.S. aquarium fish retailers sell snakeheads via the
Internet. USGS scientists purchased three species from a reputable
dealer in Rhode Island, who first requested a copy of the State permit
that allowed USGS to possess the fish in Florida. Private purchases can
also be made through several Internet ``chat rooms'' where possession
of permits is not discussed.
California: California Department of Fish and Game personnel
collected a snakehead while electrofishing in a reservoir, Silverwood
Lake, in 1997. Silverwood Lake is in the Mohave River drainage, east-
northeast of Los Angeles and north of San Bernardino in the San
Bernardino Mountains. The specimen was subsequently frozen and later
discarded (Camm Swift, pers. comm.). It was identified as Channa argus
(John Sunada, pers. comm. to W.R. Courtenay, Jr.). It is believed that
the fish got in the lake from the California Aqueduct that runs from
the San Joaquin River south of Stockton into Lake Silverwood, one of
several reservoirs that serves Los Angeles.
Hawaii: The chevron snakehead, (Channa striata) has been
established on Oahu, Hawaii, since the late 1800s and was introduced
from southern China (Herre, 1924). For whatever reasons, it does not
appear to have been introduced to other waters of Hawaii and is
confined to reservoirs on Oahu (Maciolek, 1984). In addition, the
species is now being cultured as a food fish on Oahu. This species is
regarded as carnivorous with a preference for other fishes (Moshin and
Ambak, 1983; Conlu, 1986). Lee and Ng (1991) described it as a
territorial ambush feeder. It is also used to control tilapia
populations in the Philippines (Conlu, 1986).
Maryland: Two adults and eight juveniles of Channa argus were found
in a pond in Crofton, Anne Arundel County, Maryland in late June and
early July 2002. Maryland Department of Natural Resources personnel
captured over 100 juveniles from the pond in July 2002. The adults are
known to have over-wintered in the pond. The fish were purchased from a
live food fish market in New York City, transported to Maryland, and
kept in an aquarium, and two fish were released into the pond in 2000.
This species appears to be the most common snakehead available in food
markets and restaurants as a live food fish.
New England States: A specimen of the northern snakehead, Channa
argus, was collected in October 2001 from Newton Pond, Sudbury,
Worcester County, Massachusetts, by Massachusetts Department of Fish
and Wildlife personnel. The likely source is from live food fish
markets. It is capable of establishment in most fresh waters of the
United States. Okada (1960) reported adults as voracious feeders,
particularly on other fishes.
Specimens of the giant snakehead, Channa micropeltes, have been
collected from open waters in Maine, Massachusetts, and Rhode Island
(Courtenay et al, 1984; Fuller et al., 1999). This tropical/subtropical
species could not become established in those temperate waters.
Juveniles of the species are cardinal red with two dark stripes on
either side of the body, and sold by aquarium fish retailers as red or
redline snakeheads. Aquarist-oriented web sites note that this species
requires much animal food and that growth is rapid. These sites often
advise that, once these fish reach approximately 15-20 cm in length, no
more than one individual should be kept in a single aquarium because
they are aggressive predators. The pathway into these New England
States was likely aquarists who released their ``pets'' when they grew
too large for their aquaria and/or because it was too costly to feed
them. Releases of this species into subtropical waters in southern
Florida or Hawaii could lead to establishment of this snakehead,
regarded as the most predaceous channid and known to have attacked
humans (Ng and Lim, 1990; Lee and Ng, 1991; Kottelat et al., 1993).
Uses: According to U.S. Fish and Wildlife Service Law Enforcement
data, 16,554 individuals or 20,527 kilograms of all species of
snakeheads were imported into the United States between 1997 and 2000
at a declared value of $85,425 (records of imports report numbers of
individual fish OR weight in kilograms). Importations of snakeheads
into the United States do not appear to represent a significant portion
of live fish imports at present. However, from the raw data, it is
clear that the trend has been upward in recent years.
Snakeheads have been imported into the United States for two
purposes: as aquarium fish and for use as food. In Southeast Asia,
particularly in Thailand and Malaysia, and to a lesser extent in Japan,
there are developing recreational fisheries for the larger snakehead
species (see http://www.fishingasia.com as an example).
Several species of snakeheads are listed on aquarium fish websites.
Some of these entries are for information purposes and a few others
list fish for sale. The most popular species are, in order of
importance and availability: Channa micropeltes, juveniles sold as red
or redline snakehead; C. marulius, juveniles sold as cobra snakehead;
C. bleheri, sold as rainbow snakehead; C. barca sold as barca or tiger
snakehead; C. gachua sold under a variety of names; and Parachanna
africana, juveniles sold as African snakehead. Some are cultured and
others are captured from the wild. Rarely does one see listings for C.
asiatica, C. orientalis, C. pleuropthalma, C. punctata, or C.
stewartii. This is somewhat surprising because several are attractive
aquarium fishes, and they can be purchased from dealers in southeast
Asia via the Internet. Channa bleheri, C. gachua, and C. orientalis are
small snakeheads, unlike C. micropeltes and C. marulius that grow
quickly to large sizes. All but the smallest snakeheads are unsuitable
for community tanks, and even they may kill other fishes in aquaria.
Larger snakeheads require very large aquaria and must be kept alone.
The number of aquarium hobbyists interested in keeping snakeheads
appears to be small, and snakeheads represent a minor component in the
aquarium fish industry (Marshall Myers, pers. comm. to J.D. Williams).
Conversely, use of snakeheads as food fishes is growing in the
United States (Table 3). Live snakeheads of the larger species can be
purchased in live food fish markets and in some restaurants in States
where these fishes are not prohibited, but they are also appearing in
markets in States where possession is prohibited (Howells et al.,
2002). Some restaurants display live snakeheads in aquaria, a common
practice where these fishes are native, allowing customers to choose a
fish to be prepared for a meal. This is reminiscent of many U.S.
seafood restaurants where one can select a lobster to be cooked from an
During FY 1999, the USDA Small Business Innovation Research Program
funded a Phase II project to the Hawaii Fish Company of Waialua,
Hawaii, to develop commercial culture of the chevron snakehead, Channa
striata. It is now being cultured in Hawaii as a food fish.
Table 3.--Species of the Family Channidae Currently Known To Be Cultured
for Food and/or Aquarium Fish Trade
* Species most widely cultured for food. Also being cultured in Hawaii.
** Second most important species cultured for food.
*** Appears to be the most important species cultured for the aquarium
Although several snakehead species may be found for sale alive in
live food fish markets, the most available species is the northern
snakehead, Channa argus. It is being sold in Boston and New York City,
where snakeheads are legal. Through confiscation by State fish and game
personnel in 2001, it has also been found in the live food fish trade
of three States (Florida, Texas, and Washington) where possession of
snakeheads is prohibited. The northern snakehead is able to tolerate a
considerable temperature range, from warm temperate to boreal climates,
where this species can live under ice. Additionally, its airbreathing
capabilities enhance its transport and marketing. Marketing and
customer preferences, however, are not synonymous. For example, persons
of southeastern Asian descent prefer chevron snakehead, C. striata,
above any other species. It is currently being cultured in much of
southeastern Asia, the Philippines, and Hawaii.
Potential Range: Temperature is the most important environmental
factor that would determine potential range of snakeheads in the United
States. Because there are few data providing thermal tolerance ranges
for snakeheads, potential range must be inferred from
distribution within native ranges. The family Channidae contains nine
species that are strictly tropical, and if introduced, would survive in
the warmest waters such as extreme southern Florida, perhaps parts of
southern California, Hawaii, and certain thermal spring systems and
their outflows in the American west. Another four can be considered
tropical to subtropical, indicating a similar potential range of
distribution as for tropical species but with a greater likelihood of
survival during cold winters and more northward limits. One is
subtropical. Another 12 (4 of which appear to be species complexes)
snakeheads can tolerate tropical or subtropical to warm temperate
conditions, indicative of species that could survive in most southern
States. One is warm temperate, and another warm temperate to cold
temperate (Channa argus with a temperature range of 0-30
In summary, there are few waters in the United States or
territories of the United States that, based on temperature, would
preclude some member(s) of the family Channidae from becoming
Factors That Contribute to Injuriousness
The likelihood of release or escape of snakeheads is high. One
species, Channa striata, was released and became established in waters
of Oahu, Hawaii, before 1900. It was likely introduced as a food fish.
A second species, Channa marulius, is a recent introduction to
southeastern Florida (Broward County) and has also become established.
The pathway for this introduction was release of either food or
aquarium fish. Two specimens of Channa argus were caught in the St.
Johns River near Sanford, Florida, and three more are believed to have
been caught at or near the same location. This species is available
only through live food fish markets. The same species was captured from
a pond in central Massachusetts in October 2001. The snakehead captured
in Lake Silverwood, California, was also C. argus. Two adults and eight
juveniles of C. argus were collected from a pond in Crofton, Maryland,
in June and July 2002. Individual specimens of Channa micropeltes were
caught in Maine, Massachusetts, and Rhode Island in past years, the
source of which were most likely aquarium fish releases. The
availability of 8 species of snakehead fishes in live food fish markets
and the aquarium trade raises the probability that one or more species
will be released into open water. As demonstrated by the documented
discoveries of both aquarium and food fish species of snakeheads in the
wild, there is a high likelihood that snakeheads would escape or be
If snakeheads escaped, or were released into the wild, the
likelihood that they would survive and/or become established with or
without reproduction is dependent upon the species of snakehead
involved and the location of the release. The family Channidae contains
9 species that are strictly tropical, 4 can be considered tropical to
subtropical, one is subtropical, 12 can tolerate tropical or
subtropical to warm temperate conditions, one is warm temperate, and
one is warm temperate to cold temperate. The tropical species would
survive in the warmest waters such as extreme southern Florida, perhaps
parts of southern California, Hawaii, and certain thermal spring
systems and their outflows in the American west. The tropical to
subtropical species would have a similar potential range of
distribution as for tropical species but with a greater likelihood of
survival during cold winters and more northward limits. The tropical or
subtropical to warm temperate species could survive in most southern
States. The warm temperate, and warm temperate to cold temperate,
species could survive in most areas of the United States.
That Channa striata, a tropical to warm temperate species cultured
for the live food trade, has been established for over a century in
Hawaii and, more recently, C. marulius, a tropical to warm temperate
species cultured for the aquarium trade, has become established as a
reproducing population in southeastern Florida is indicative of the
likelihood of survival and potential for establishment of snakehead
fishes. Although C. striata is largely confined to reservoirs on Oahu,
C. marulius has ample opportunity to expand its range in southeastern
Florida through the large network of interconnected canals and Water
Conservation Areas to the west of the metropolitan areas. The release
of live food or aquarium fishes is a viable pathway for introduction of
snakehead fishes and, depending on temperature, many species could
become established from Florida to or above the U.S.-Canadian border
and in many territories of the United States.
The likelihood and magnitude of spread would be high for all
species within their thermal limits. Both the northern snakehead,
Channa argus, and, to a somewhat lesser extent, the blotched snakehead,
C. maculata, expanded their ranges of distribution from sites of
initial introduction in Japan. Since introduction of the northern
snakehead into the Aral Sea basin in the 1960s, there has been a
dramatic range expansion in waters of Kazakhstan, Turkmenistan, and
Uzbekistan. Range expansion also occurred in the Philippines following
introduction of the chevron snakehead, C. striata.
Although there is limited information on the fecundity of
snakeheads, scientific data indicate that fecundity increases greatly
in larger snakeheads and follows increasing body length. According to
Quayyum and Quasim (1962), fecundity for C. striata, a medium-sized
snakehead species, ranges from 2,300 to 26,000 [ouml]cytes. Larger
species, such as C. marulius and C. argus can produce 40,000 to 50,000
[ouml]cytes. Given that two individual northern snakeheads, C. argus,
were reportedly released into the pond in Crofton, Maryland, and
successfully reproduced two times in the summer of 2002, and that
several species of snakeheads are known to have a high fecundity, there
is a high likelihood that snakeheads would be capable of spreading
within their thermal limits.
Several species of snakeheads, whose native ranges are subject to
seasonal dry/wet conditions, are known to be capable of overland
migrations. According to Peter Ng (pers. comm. to W.R. Courtenay, Jr.)
some species can crawl sinuously on land, even dry land, from point to
point. There are 2 main groups of snakeheads that are slow, but
effective and directed, at overland migrations. One group, including C.
striata, C. micropeltes, C. asiatica and C. gachua, has a more dorso-
ventrally flattened body with a somewhat flatter belly and can crawl on
land. The second group, including C. argus, C. maculata and C. lucius,
has a more laterally compressed or rounded body and is not as
successful at overland migrations. For those species that are not
capable of overland migration, there is a high likelihood that they can
be transferred to other water bodies through flooding if they are
released into flood-prone areas. In summary, there are few waters in
the United States or territories of the United States that, based on
temperature, would preclude some member(s) of the family Channidae from
becoming established and expanding their ranges through reproduction
and/or overland migration.
At all life stages, snakeheads will compete for food with native
species. As discussed above in the Biology section, snakehead fry feed
on zooplankton; juveniles feed on insect larvae, small crustaceans, and
fry of other fishes; and
adults are predators, feeding on other fishes, crustaceans, frogs,
smaller reptiles (snakes, lizards), and sometimes birds (particularly
young waterfowl) and mammals. Native fish and wildlife populations that
prey upon fishes, crustaceans, frogs, snakes, lizards, and young
waterfowl would face reductions resulting from the loss of food
Although the literature on snakeheads does not include specific
information on feeding habits of every species, what is universal for
those species that have been studied in this respect is that fishes are
an important component of snakehead diets. This can range, for example,
from approximately 20-30% (e.g., Channa gachua) of the diet to well
over 90% (e.g., C. argus, C. micropeltes, C. striata). Next in line to
fishes, crustaceans (particularly shrimp, etc.) form a substantial
dietary component for snakeheads. Native fish populations in particular
would likely be reduced through predation if snakeheads were introduced
and became established in bodies of water. Through predation, ecosystem
balance and predator-prey relationships could be modified drastically
should snakeheads become established in waters with low diversity of
native fishes and low abundance or absence of native predatory species.
Therefore, the likelihood and magnitude of adverse impacts on native
wildlife through competition for food and predation on native wildlife
While the potential for snakeheads to transfer pathogens to native
wildlife is largely unknown, all snakehead species examined are host to
at least several species of parasites. At least two snakehead species,
Channa punctata and C. striata, are susceptible to epizootic ulcerative
syndrome (EUS), a disease believed to be caused by several species of
bacteria, a fungus, and perhaps a retrovirus, under intensive culture
conditions. EUS is not specific to snakeheads and has affected other
fishes, such as clariid catfishes, bagrid catfishes, two cyprinid
genera, mastacembalid eels, and a nandid fish in India; in Thailand, it
has been found in giant gourami and climbing perch. Although there have
been no studies undertaken to examine transfer of parasites or diseases
from snakeheads to native North American fishes, there are numerous
cases documented in the scientific literature where nonnative species
have transferred diseases and pathogens to native species. Several of
the parasites of northern snakeheads listed in Table 2 are known to
affect salmonids, cyprinids, and percids. Therefore, there is a
credible evidence on the potential for snakeheads to transfer pathogens
to native fishes.
Due to the highly predatory nature of snakeheads, the likelihood
and magnitude of effect on threatened and endangered species is high.
Of all the taxa listed as endangered or threatened in U.S. aquatic
habitats, 16 amphibians, 115 fishes, and 5 of the 21 crustaceans (the
surface-dwelling crayfish and shrimp) would be the most likely to be
affected. Based on habitat requirements and life history, fishes are
more likely to be affected by introduced snakeheads than amphibians and
the surface-dwelling crustaceans. Nonetheless, the possibility of an
additional nonindigenous predator in the aquatic community with any
listed amphibian or crustacean would constitute a threat.
In the western United States, habitat requirements of listed fishes
range from steep-gradient, coldwater mountain streams, lower-gradient
large desert rivers, to thermal (warm) springs in desert areas. Eastern
fishes likewise occupy a variety of habitats, including springs,
creeks, large rivers, and the Great Lakes. One or more species of
snakeheads would be capable of living in any of the above habitats.
Since all snakehead species prey on fish, to a greater or lesser
extent, all of the fishes listed as endangered or threatened would be
vulnerable to predation at some stage in their life history. The degree
of threat would vary from extremely high for any species of snakeheads
introduced in relatively small, isolated habitats, such as desert
thermal springs and their outflows in the American southwest, to
somewhat less in steep-gradient coldwater mountain streams. Based on
the food habits and habitat preferences of snakeheads, it is likely to
invade the habitat, feed on, and further threaten Federally listed
freshwater fishes. Snakeheads are likely to also further threaten
candidates for Federal protection.
The likelihood that one or more species may be placed in danger of
extinction or become endangered within the foreseeable future as a
result of introduction/establishment is high. The introduction of a
small number of individuals (<5) into isolated spring habitats could
result in the extinction of endemic spring-adapted fishes or
crustaceans. The snakeheads would not have to establish a reproducing
population to reduce or eliminate a fish or crustacean species confined
to a small section of a stream or isolated spring habitat. Any
snakehead that becomes established in a water body would represent a
significant threat and could potentially push any listed amphibian,
fish, or crustacean to extinction.
The likelihood and magnitude of ancillary wildlife resource damage
due to control measures is high. Chemical control using rotenone or
other similar toxins that work by preventing fish from removing oxygen
from the water would likely be damaging to nontarget native organisms.
Only one species of snakehead, Channa micropeltes, a tropical/
subtropical species, is reported to have attacked human beings. There
have been reports of human deaths as a result. All such incidents
apparently happened when humans approached a nest or group of young,
and attacks were perpetrated by guarding adults. However, the
likelihood and magnitude of direct impacts on human beings is low.
Factors That Reduce or Remove Injuriousness
The ability to eradicate or control snakehead populations depends
on where they are found. However, there is no known method of removing
all snakeheads following introduction. If established in large lakes or
river systems, eradication and/or control are expected to be nearly
impossible, and snakeheads would likely become permanent members of the
fish community. Control in smaller water bodies depends upon the amount
of vegetation, the accessibility to the water body, and the
effectiveness of the control methods. Piscicides work by preventing
fish from removing oxygen from the water. Chemical control using
rotenone and similar toxins would likely be ineffective to airbreathing
snakeheads and damaging to nontarget organisms except in closed
situations. Electrofishing and netting may provide some level of
control of snakehead populations; however, eradication using these
methods would be too selective on size classes to remove a population
of snakeheads. When a population is discovered, it is typically too
late for removal unless the population is isolated.
Since effective measures to eradicate, manage, or control the
spread of snakeheads once they are established are not currently
available, the ability to rehabilitate or recover ecosystems disturbed
by the species is low. Re-establishment of extirpated populations of
native amphibians, fishes, and crustaceans, if biologically possible,
would be labor and cost intensive and would depend on eradication of
snakeheads within those habitats.
Because several species of snakehead fishes are available through
aquarium, restaurant, and the live food fish trades, the likelihood
that they would escape or be intentionally released into the wild is
high. If they escape or are intentionally released, they are likely to
survive or become established within their respective thermal limits.
Because there are no known limiting factors, because some species have
the ability to move across land, and because snakeheads have a fairly
high reproductive potential, they are likely to spread once they are in
the wild. Snakeheads fishes are likely to compete with native species
for food, may transmit parasites to native species, and are likely to
feed on native species, which will negatively affect native fishes,
amphibians, crustaceans, birds, small reptiles, and small mammals. The
air-breathing and mobile characteristics of snakeheads increase the
difficulty in preventing, eradicating, managing, or controlling their
spread. Because the successful removal of all individual snakeheads
from a water body would be very difficult to accomplish, it will be
very difficult rehabilitate or recover ecosystems disturbed by
snakeheads. In conclusion, for the reasons stated above, the Service
finds snakeheads to be injurious to the wildlife and wildlife resources
of the United States.
We are making this rule effective upon publication. In accordance
with the Administrative Procedure Act, we find good cause as required
by 5 U.S.C. 553 (d)(3) to make this rule effective less than 30 days
after publication in the Federal Register. Approximately 2.94 times
more snakeheads were imported in July 2002 than in July 2001.
Inspectors at ports of entry have noticed an increase in interest in
importing snakeheads before the final rule becomes effective; some
importers have told inspectors that they are trying to ``beat the ban''
and import as many snakeheads as possible before the prohibition on
importation and interstate transportation is imposed. Because we have
already documented a nearly three-fold increase in the importation of
snakeheads from one year ago, and because of the increased interest in
importing snakeheads before the final rule becomes effective, the
Service believes that there will be a substantial and significant
increase in the numbers of snakehead fishes imported and transported
across State lines if this rule is effective 30 days after publication
in the Federal Register. The increases in importations and interstate
transportations during that 30-day period could result in a significant
potential for damage to the wildlife and wildlife resources of the
United States. As discussed previously in the preamble to this rule,
snakehead fishes are highly predatory, are difficult to control, and
are difficult to differentiate among species. Therefore, we believe
that we have sufficient evidence and cause to take immediate action to
prohibit further importation and interstate movement of the entire
Channidae family of snakehead fishes.
Paperwork Reduction Act
This rule contains information collection activity for special use
permits. The Fish and Wildlife Service has approval from OMB to collect
information under OMB control number 1018-0093. This approval expires
March 31, 2004. The Service may not conduct or sponsor, and a person is
not required to respond to, a collection of information unless it
displays a currently valid OMB control number.
Regulatory Planning and Review
In accordance with the criteria in Executive Order 12866, the
Office of Management and Budget has determined that this rule is not a
significant regulatory action.
(a) This rule will not have an annual economic effect of $100
million or adversely affect an economic sector, productivity, jobs, the
environment, or other units of the government. A cost-benefit and
economic analysis is not required.
The net economic effect of prohibiting the importation and
interstate transportation of snakeheads is difficult to determine
because of the minimal amount of data available for a relatively new
species to the aquarium, live fish markets, and restaurant trades.
There is a trade-off between damage avoided by not letting snakeheads
get into U.S. water bodies and the economic benefits received by fish
markets and aquarium owners who want to own the species. Since only
$85,000 worth of snakeheads were imported during the four-year period
between 1997 and 2000, and the potential damage by snakeheads if they
get into U.S. waters would be in the millions of dollars from the loss
of native species, including threatened and endangered species, this
rule will have a net positive benefit. The dollar amount of imported
and traded value is not the net economic value of this fish, but the
relatively small value compared to environmental damage avoided by
prohibiting these species is convincing that this rule will not have a
major negative economic effect.
(b) This rule will not create inconsistencies with other agencies.
This rule pertains only to regulations promulgated by the Fish and
Wildlife Service under the Lacey Act. No other agencies are involved in
(c) This rule will not materially affect entitlements, grants, user
fees, loan programs, or the rights or obligations of their recipients.
This rule does not affect entitlement programs. This rule is aimed at
regulating the importation and movement of nonindigenous species that
have the potential to cause significant economic and other impacts on
(d) This rule does not raise novel legal or policy issues. No
previous listings of wildlife as injurious have raised legal or policy
Regulatory Flexibility Act and SBREFA
This rule will not have a significant economic effect on a
substantial number of small entities as defined under the Regulatory
Flexibility Act (5 U.S.C. 601 et seq.). A Regulatory Flexibility
Analysis is not required. Accordingly, a Small Entity Compliance Guide
is not required. The rule is not a major rule under 5 U.S.C. 804(2),
the Small Business Regulatory Enforcement Fairness Act. This rule will
not have an annual effect on the economy of $100 million or more, and
does not have significant adverse effects on competition, employment,
investment productivity, innovation, or the ability of U.S.-based
enterprises to compete with foreign-based enterprises.
No individual small industry within the United States will be
significantly affected if snakehead importation and interstate
transport are prohibited. Live food fish markets, restaurants, and
aquarium hobbyists are the entities most likely to be affected by this
rule. The number of aquarium hobbyists interested in keeping snakeheads
appears to be small, and snakeheads represent a minor component in the
aquarium fish industry (Marshall Myers, pers. comm.. to J.D. Williams).
With only 16,554 individual snakeheads imported over four years and
most of these going to markets and restaurants for human consumption,
the number of entities engaging in selling and buying these fish is
very small. There is no recreational fishery for these species. The
number of entities involved in the trade of these species is not known,
but it is assumed to be very small because of the small number of these
fish imported. This rulemaking will have the indirect effect of
protecting native fishes, amphibians, and crustaceans from the
intentional or accidental
introduction of snakeheads into U.S. water bodies. The snakeheads would
likely devastate many native wildlife populations if introduced into a
waterway. It is very unlikely that this rulemaking will affect a
substantial number of small entities and those entities affected will
not be significantly affected because of the very small numbers of
these fish imported. This rulemaking, by protecting the environment
from the spread of a nonnative species that would devastate native
fishes, amphibians, and crustaceans, will indirectly work to sustain
the economic benefits enjoyed by numerous small establishments engaged
in the recreational fishing industry, among others.
This rule will not cause a major increase in costs or prices for
consumers, individual industries, Federal, State, or local government
agencies, or geographic regions. This rulemaking will not affect costs
or prices for any fish species other than snakeheads. Once this rule is
published, and importation and interstate movement are prohibited, the
maximum loss would be approximately $22,000 per year to the few
entities that deal in these species.
Unfunded Mandates Reform Act
In accordance with the Unfunded Mandates Reform Act (2 U.S.C. 1501
et seq.), the rule will not ``significantly or uniquely'' affect small
governments. A Small Government Agency Plan is not required. The
Service has determined and certifies pursuant to the Unfunded Mandates
Reform Act that this rulemaking will not impose a cost of $100 million
or more in any given year on local or State governments or private
entities; will not produce a Federal mandate of $100 million or greater
in any year and therefore, is not a ``significant regulatory action''.
In accordance with Executive Order 12630, the rule does not have
significant takings implications. A takings implication assessment is
not required. This rule will not impose significant requirements or
limitations on private property use.
In accordance with Executive Order 13132, the rule does not have
significant Federalism effects. A Federalism assessment is not
required. This rule will not have substantial direct effects on States,
in the relationship between the Federal Government and the States, or
on the distribution of power and responsibilities among the various
levels of government. Therefore, in accordance with Executive Order
13132, we determine that this rule does not have sufficient Federalism
implications to warrant the preparation of a Federalism Assessment.
Civil Justice Reform
In accordance with Executive Order 12988, the Office of the
Solicitor has determined that the rule does not unduly burden the
judicial system and meets the requirements of sections 3(a) and 3(b)(2)
of the Executive Order. The rule has been reviewed to eliminate
drafting errors and ambiguity, was written to minimize litigation,
provides a clear legal standard for affected conduct rather than a
general standard, and promotes simplification and burden reduction.
We have reviewed this rule in accordance with the criteria of the
National Environmental Policy Act and our Departmental Manual in 516
DM. This rule does not constitute a major Federal action significantly
affecting the quality of the human environment. Since only 16,554
snakehead fishes were imported between 1997 and 2000 for a declared
value of $85,000, the maximum annual loss to the few entities that deal
in these species is estimated to be $22,000. Therefore, an
environmental impact statement/assessment is not required. The action
is categorically excluded under the Department's NEPA procedures (516
DM 2, Appendix 1.10), which apply to policies, directives, regulations,
and guidelines of an administrative, legal, technical, or procedural
nature; or the environmental effects of which are too broad,
speculative, or conjectural to lend themselves to meaningful analysis
and will be subject later to the NEPA process, either collectively or
on a case-by-case basis.
In accordance with the President's memorandum of April 29, 1994,
``Government-to-Government Relations with Native American Tribal
Governments'' (59 FR 22951), Executive Order 13175, and 512 DM 2, we
have evaluated potential effects on Federally recognized Indian tribes
and have determined that there are no potential effects. This rule
involves the importation and interstate movement of live snakeheads. We
are unaware of trade in these species by Tribes.
Effects on Energy
On May 18, 2001, the President issued Executive Order 13211 on
regulations that significantly affect energy supply, distribution, and
use. Executive Order 13211 requires agencies to prepare Statements of
Energy Effects when undertaking certain actions. Because this rule is
intended to prevent the accidental or intentional introduction of
snakeheads and the possible subsequent establishment of populations of
these fish in the wild, it is not a significant regulatory action under
Executive Order 12866 and is not expected to affect energy supplies,
distribution, and use. Therefore, this action is a not a significant
energy action and no Statement of Energy Effects is required.
A complete list of all references cited in this rule is available
upon request from the Division of Environmental Quality (see FOR
FURTHER INFORMATION CONTACT section).
The Fish and Wildlife Service is issuing this final rule under the
authority of the Lacey Act (18 U.S.C. 42).
List of Subjects in 50 CFR Part 16
Fish, Imports, Reporting and recordkeeping requirements,
For the reasons discussed in the preamble, we amend part 16,
subchapter B of chapter I, title 50 of the Code of Federal Regulations
as set forth below.
1. The authority citation for part 16 continues to read as follows:
Authority: 18 U.S.C. 42.
2. Amend Sec. 16.13 by revising paragraph (a)(2) to read as
Sec. 16.13 Importation of live or dead fish, mollusks, and
crustaceans, or their eggs.
(a) * * *
(2) The importation, transportation, or acquisition of any of the
species listed in this paragraph is prohibited except as provided under
the terms and conditions set forth in Sec. 16.22:
(i) Live fish or viable eggs of walking catfish, family Clariidae;
(ii) Live mitten crabs, genus Eriocheir, or their viable eggs;
(iii) Live mollusks, veligers, or viable eggs of zebra mussels,
genus Dreissena; and
(iv) Any live fish or viable eggs of snakehead fishes of the genera
Channa and Parachanna (or their generic synonyms of Bostrychoides,
Ophicephalus, Ophiocephalus, and Parophiocephalus) of the Family
Channidae, including but not limited to:
(A) Channa amphibeus (Chel or Borna snakehead).
(B) Channa argus (Northern or Amur snakehead).
(C) Channa asiatica (Chinese or Northern Green snakehead).
(D) Channa aurantimaculata.
(E) Channa bankanensis (Bangka snakehead).
(F) Channa baramensis (Baram snakehead).
(G) Channa barca (barca or tiger snakehead).
(H) Channa bleheri (rainbow or jewel snakehead).
(I) Channa cyanospilos (bluespotted snakehead).
(J) Channa gachua (dwarf, gaucha, or frog snakehead).
(K) Channa harcourtbutleri (Inle snakehead).
(L) Channa lucius (shiny or splendid snakehead).
(M) Channa maculata (blotched snakehead).
(N) Channa marulius (bullseye, murrel, Indian, great, or cobra
(O) Channa maruloides (emperor snakehead).
(P) Channa melanoptera.
(Q) Channa melasoma (black snakehead).
(R) Channa micropeltes (giant, red, or redline snakehead).
(S) Channa nox.
(T) Channa orientalis (Ceylon or Ceylonese Green snakehead).
(U) Channa panaw.
(V) Channa pleurophthalmus (ocellated, spotted, or eyespot
(W) Channa punctata (dotted or spotted snakehead).
(X) Channa stewartii (golden snakehead).
(Y) Channa striata (chevron or striped snakehead).
(Z) Parachanna africana (Niger or African snakehead).
(AA) Parachanna insignis (Congo, square-spotted African or light
(BB) Parachanna obscura (dark African, dusky, or square-spotted
* * * * *
Dated: September 26, 2002.
Acting Assistant Secretary for Fish and Wildlife and Parks.
[FR Doc. 02-25337 Filed 10-3-02; 8:45 am]
BILLING CODE 4310-55-P