Bowfin (Amia calva)
Chris Rego
AbstractThe Bowfin, Amia calva, is a primitive fish native to North America capable of breathing air. The
Bowfin is a predacious fish, often caught by anglers fishing for something else. Bowfin are found
in slow moving, vegetated areas where they build nests. Bowfin populations are stable.
Bowfin
Amia calva (Linnaeus, 1766)
Context and Content- Order Amiiformes,
Family Amiidae, Genus Amia. A.calva is the
only extant species in the order Amiiformes,
which flourished in the mid-Mesozoic
period (Wilson 1982).
General Characteristics- The Bowfin is a
long, heavy bodied fish with a rounded,
heterocercal caudal fin. They can easily be
distinguished from all other North American
native fish by the presence of a long dorsal
fin separated from the caudle fin, a short
anal fin, and a single gular plate. The bowfin
has a large mouth with many sharp teeth.
Bowfin are generally olive in color with
some dark mottling in some individuals. The
undersides are whitish or light in color.
Males and juveniles have an ocellus (dark
spot) on the caudal fin. This spot loses
distinction in adult females. Bowfin have
10-13 brachiostegal rays and two barbels on
the snout, as well as 65-70 lateral line
scales, 45-48 dorsal rays, 9-10 anal rays, and
16-18 pectoral rays (Ross 2001).
Bowfin have been recorded at lengths of
1090 mm, but are more commonly found
from 381-685 mm. The U.S. Angling record
is 9.76 kg caught in South Carolina in 1980.
Male bowfin are typically smaller than
females (Ross 2001).
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Distribution- Bowfin are widespread and
found in most water systems and drainages
in Mississippi, including, but not limited to,
the Mississippi, Pascagoula, Pearl, and
Tombigbee drainages. In the North
America, Bowfin are found throughout the
eastern portion of the United Sates and
parts of Southern Canada. They can be
found in the Mississippi, St. Lawrence-Lake
Champlain, and Great Lakes basins (except
Lake Superior). The Bowfin is also found in
many Atlantic drainages from the Hudson,
south into Florida and can be found
throughout the Gulf of Mexico Coastal Plain
from Florida west into Texas (Ross 2001).
Form and Function- The Bowfin’s
distinguishing dorsal fin allows for slow
moving both forward and backward by the
use of wave-like undulations generated by
the muscles attached to the dorsal rays.
This is called ribbon-fin locomotion
(Jagnandan 2012).
Bowfin posses the ability to breath air, that
is, to acquire needed oxygen from the air.
This is accomplished by the use of a highly
vascularized swim bladder as a “lung” for
gas exchange. Bowfin have a physostomous
swim bladder, meaning there is a
connection from the swim bladder to the
gut via the pneumatic duct. It is because of
this connection that Bowfin can breathe air.
Bowfin breathe by exhaling the old air in
the swim bladder and quickly inhaling new
air (Horn and Riggs 1973). An increase in air
breathing occurs as water temperatures
rise. At 10°C, Bowfin rely almost solely on
their gills for respiration but at 30°C, Bowfin
get most of their oxygen from the air.
Interestingly though, even at high
temperatures, the Bowfin uses its gills for
around 60% of CO2 elimination. (Johansen
et al. 1970)
The gills of Bowfin are also unique among
most fish. The gill lamellae are fused so that
the tips are held apart from each other. This
adaptation allows for gas exchange in air,
while water is not holding the tips apart
(Bevelander 1934).
Bowfin can survive out of water for hours,
and even days at a time. Green (1966)
reports of a Bowfin surviving 21 days buried
in the mud of a dried up pond.
Ontogeny and Reproduction- Bowfin breed
in the spring in Mississippi. Spawning
activity begins as water temperatures reach
12°C and continues through 26°C, with peak
spawning occuring at 18°C. Males construct
a bowl shaped nest in shallow weedy areas
of depths between 61-92 cm (Hildebrand
and Towers 1928; Reighard 1903).
Courtship begins when a male approaches a
female and holds her by the snout with his
jaws. He then begins to swim circles around
the nest. Next, the male moves to lie
parallel to the female, with his snout just
behind her pectoral fin. Spawning begins as
the male starts vibrating his fins and the
female sheds the eggs and they are
fertilized. The courtship ritual may take
over an hour and the pair may repeat it up
to five times. Bowfin spawn both day and
night, but show preference to the night
(Reighard 1903). After spawning, the female
leaves the nest but the male stays to
vigorously guard the eggs (Kelly 1924).
Females may contain as many as 64,000
eggs. Mature eggs have a yellowish
appearance and they are slightly elliptical
(2.2 x 2.8 mm). The eggs are adhesive and
stick to objects such as roots or vegetation.
After fertilization, the eggs hatch in 180
hours (Ross 2001; Breder and Rosen 1966).
At hatch, the fry measure 3-7 mm and are
tadpole in shape. Each individual has a yolk
sac until the fry reach 10-13 mm. The newly
hatched fish have an adhesive organ which
they use to attach to vegetation in the nest
(Reighard 1934). The male guards the fry in
the nest for about nine days. Then the fry
leave the nest in a compact school, still
vigorously guarded by the male. The fry stay
in the school until about 102 mm, and then
the solitary life of adults begins (Ross 2001).
Bowfin become sexually mature in two to
three years and generally do not live more
than ten years in the wild (Pflieger 1975).
Growth can be rapid, with fish reaching 203
mm in the first year and 378-397 mm by
their second (Becker 1983; Scott and
Crossman 1973).
Ecology- Bowfin prefer habitats that include
sluggish waters, vegetation, and annual
flooding. Bowfin can commonly be found in
oxbow lakes, slow rivers, and swamps.
During high water stages, Bowfin move out
into the flood plain. Because of this
migration into the floodplain, Bowfin have
developed a response to lowering water
levels. As flood waters recede, Bowfin will
actively swim with the currents back to the
main river channel to avoid being trapped
in drying pools (Greenbank 1956).
Bowfin are predators. Berry (1955) showed
that, 97% of the stomach contents of adult
Bowfin consisted of various fish species
such as: Black Crappie, White Catfish, and
Brown Bullheads. Other prey items include
large crustaceans such as crayfish and grass
shrimp (Stacy et al. 1970; Pflieger 1975).
Juvenile Bowfin feed mainly on small
crustaceans such as copepods and on
insects such as dragon fly larvae. Fish
smaller than 39 mm tend to feed more on
small crustaceans and fish between 39-59
mm begin to feed more on aquatic insects
and other appropriate sized foods. At
around 102 mm, Bowfin begin to predate
on small fish in addition to insects and
crustaceans (Stacy et al. 1970; Pflieger
1975; Frazer et al. 1989).
Conservation- Bowfin populations are
secure throughout their range. However,
Bowfin are susceptible to habitat changes
from slow, sluggish systems with lots of
vegetation to systems with faster waters
and little vegetation. In Mississippi, the
Bowfin is regarded as a non-game fish and
as such, has no regulation on harvest
(MDWFP 2013).
Remarks- The Bowfin has many local names
such as: Choupique (pronounced Shoe-
pick), grinnel, grinner, dogfish, mudfish,
spottail, and cypress trout. (Ross 2001)
Bowfin are known among fishermen for
their fight on the line. Bowfin can be caught
on most types of lures and baits from Texas
Rigged soft lures to all styles of cut baits
used to catch catfish and everything in
between.
Bowfin do have commercial value, not
necessarily for their meat, but for their
eggs. Louisiana began marketing Bowfin roe
as a less expensive caviar called
“Choupiquet Royal” (Arceneaux 1992)
Literature CitedArceneaux, H. 1992. Mining golden eggs
from choupique. La. Conserv. (March/April):
8-10.
Becker, G. C. 1983. Fishes of Wisconsin.
Univ. Wisconsin Press, Madison.
Berry, F. H. 1955. Food of the mudfish
(Amia calva) in lake Newnan, Florida, in
relation to its management. Quart. J. Fla.
Acad. Sci. 18(1): 69-75.
Bevelander, G. 1934. The gills of Amia calva
specialized for respiration in oxygen
deficient habitat. Copeia 1934(3): 123-127.
Pfliger, W. L. 1975. The fishes of Missouri.
Missouri Department of Conservation,
Jefferson City.
Breder, C. M., and D. E. Rosen. 1966. Modes
of reproduction in fishes. American
Museum of Natural History, The Natural
History Press, Garden City, NY.
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volume. G. H. Parker, ed. Henry Holt & Co.,
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1989. Diet of juvenile bowfin, Amia calva
Linnaeus, in the Sipsey River, Alabama.
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under ice. Copeia 1956(3): 158-162.
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temperature and light on the rate of air
breathing of the bowfin, Amia calva. Copeia
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in the bowfin, Amia calva: morphological
design and kinematics. UMI Dissertation
Publishing 2012.
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young. Copeia 1924(133):73-74.
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Avault Jr. 1970. Food habits of the bowfin in
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