Picture by Chad Thomas, Texas State University-San Marcos Texas
Charleston, South Carolina (Linnaeus 1766).
Etymology/Derivation of Scientific Name
Amia, an ancient Greek name for a type of fish, probably the bonito (Sarda sarda); calva, Latin, meaning “smooth” (Wallus et al. 1990).
Amia calva Linnaeus 1766:500; Hildebrand and Towers 1928:113; Cook 1959:64 (Ross 2001).
Maximum size: 1090 mm, (43 in) TL (Page and Burr 1991).
Coloration: Dark greenish above, lighter below, with dark reticulations on body and some fins; males with black spot on the dorsal part of the caudal base (Miller and Robison 2004).
Counts: Lateral line scale count 62-70; 42-53 dorsal fin soft rays; 9-12 anal fin soft rays (Mansueti and Hardy 1967); 16-18 pectoral fin soft rays; 9 pelvic fin soft rays (Heufelder 1982).
Body shape: Long, robust body; head conical (Mansueti and Hardy 1967).
Mouth position: Terminal (Goldstein and Simon 1999).
Morphology: Large bony gular plate (Goldstein and Simon 1999); single, long, dorsal fin; rounded pectoral, pelvic, and caudal fins (Scott and Crossman 1973); heterocercal tail (Heufelder 1982); scales cycloid; anterior nostrils at end of short barbels (Mansueti and Hardy 1967). Gut rudimentary spiral valve (Goldstein and Simon 1999) which can function as lung (Wallus et al. 1990); jaws with numerous strong, conical teeth (Mansueti and Hardy 1967; Wallus et al. 1990).
Distribution (Native and Introduced)
U.S. distribution: Occur from the Great Lakes and drainages southward to central Texas and eastward throughout Florida; introduced populations now occur in Appalachian streams (Hubbs et al. 1991).
Texas distribution: Found in the Red, San Jacinto, and Sabine river systems and in the downstream reaches of the Brazos and Colorado basins (Hubbs et al. 1991). Warren et al. (2000) listed the following drainage units for distribution of Amia calva in the state: Red River (from the mouth upstream to and including the Kiamichi River), Sabine Lake (including minor coastal drainages west to Galveston Bay), Galveston Bay (including minor coastal drainages west to mouth of Brazos River), Brazos River, Colorado River.
[Additional literature noting collection of this species from Texas locations includes, but is not limited to the following: Bettoli et al. (1993); Linam et al. (1994); Gelwick and Li (2002); Hubbs (2002).]
Abundance/Conservation status (Federal, State, Non-government organizations):
Currently stable (Warren et al. 2000).
Macrohabitat: Sluggish lowland waters (Burgess and Gilbert 1980).
Mesohabitat: Clear waters, often abundantly vegetated (Burgess and Gilbert 1980). According to Cahn (1927) species commonly found in weed beds just over the edge of sand bars. Fish are able to survive in poorly-oxygenated habitat; when the area no longer holds water, fish may burrow in the mud and reemerge when water has returned (Neill 1950; Green 1966). Able to gulp air at water surface (Burgess and Gilbert 1980; Katula and Page 1986) and tolerates high temperatures (Burgess and Gilbert 1980).
Spawning season: In the spring (Hildebrand and Towers 1928; Burgess and Gilbert 1980) or early summer (Breder and Rosen 1966); late-March to June (Wallus et al. 1990); at water temperatures between 16-19°C, (61-66°F) (Mansueti and Hardy 1967; Heufelder 1982; Wallus et al. 1990). In southeastern Louisiana, spawning occurred in late February and early March (Davis 2006).
Spawning location: Occurs in vegetated areas in shallow water (Breder and Rosen 1966; Burgess and Gilbert 1980); also under stumps, logs, and bushes (Mansueti and Hardy 1967; Wallus et al. 1990). Katula and Page (1998) observed a nest located near the shore of a heavily vegetated pond in shallow water; nest had been constructed on flooded terrestrial grasses; the shoots of grasses had been broken off during nest construction, and the bottom of the nest was mud with exposed roots. Phytophils – plant material nesters that have adhesive eggs and free embryos that hang on plants by cement glands (Breder and Rosen 1966; Balon 1975; Simon 1999).
Reproductive strategy: Guarders; nest spawners (Simon 1999). Spawning usually occurs at night, occasionally by day, lasting 1-3 hours (Mansueti and Hardy 1967). Males build circular nests (Burgess and Gilbert 1980), guard eggs during incubation, and protect schooling young after hatching (Cahn 1927; Hildebrand and Towers 1928; Burgess and Gilbert 1980; Wallus et al. 1990). By fanning the caudal and pectoral fins, and using the snout to break off plant shoots, the male clears a large circular nest area 460-760 mm (18-30 in) in diameter, and 100-200 mm (4-8 in) deep which may have a tunnel-like entrance at one side through dense vegetation. After a female appears, the pair circle about touching intermittently, finally positioning themselves side by side where the female then lays the eggs and the male fertilizes; this process may occur up to 6 times. A male may spawn with successive females, and a single female may spawn in multiple nests. Male guards nest aggressively, until the young are at least 102 mm (4 in) long. Young leave the nest in a group, while the male slowly circles them, in an effort to prevent any from becoming separated (Breder and Rosen 1966).
Fecundity: In Louisiana, mean fecundity was about 23,000 eggs, with a range of 1,900-72,500 eggs; mean number of eggs per gram of body weight was 15 eggs/gram of body weight; mean egg diameter was 2.0 mm (.08 in) from December to April; females that did not spawn retained and reabsorbed eggs (Davis 2006). 23,600 eggs produced by female measuring 480 mm (19 in); 64,000 eggs reported from ovaries of a 530 mm (21 in) fish (Vessel and Eddy 1941). In Missouri, relationship between body length and number of eggs was variable – mature females (470-843 mm, 18.5-33.2 in TL) averaged 21,332 eggs per fish; an 843 mm (33.2) TL female had 98,737 eggs (Wallus et al. 1990). Eggs slightly elliptical in shape; hatching in 180 hours (Breder and Rosen 1966). Katula and Page (1998) reported collection of eggs from a nest, which were black in color, and measured 2 mm (.08 in) in diameter. Eggs creamy-yellow when first laid, darkening quickly; white to yellowish brown animal pole and charcoal gray to dark, grayish brown yolk; eggs darken with age, and vary in color with locality (Mansueti and Hardy 1967; Wallus et al. 1990). According to Davis (2006), spawning behavior is completed between 16 and 25 days; this based on the following information from earlier studies: 1-6 day time frame for nest construction and egg deposition, 8-10 days for hatching, and 7-9 days for yolk-sac absorption while larvae is attached to vegetation.
Age at maturation: In southeastern Louisiana, most fish were mature by age 2 (Davis 2006). In Canada, males and females may mature from age 3-5 (Wallus et al. 1990). Minimum TL at maturation is reported at about 380 mm, 15 in (Trautman 1957; Wallus et al. 1990).
Migration: During high water, bowfin move into floodplain habitats and return to the river channel as floodplains start to become dry (Davis 2006; Greenbank 1956). Migration during spawning season has been reported (Mansueti and Hardy 1967; Wallus et al.1990).
Longevity: 10 years reported from Louisiana; females were older than males (Davis 2006). Fish in captivity may live up to 30 years (Carlander 1969).
Food habits: First and second level trophic classifications: carnivore and whole body, respectively; trophic mode: ambush (in conjunction with protective resemblance); feeding behavior: clumsy predatory opportunist, generalist, nocturnal; main food items include fishes, crayfish, and frogs (Burgess and Gilbert 1980; Goldstein and Simon 1999). In southeastern Missouri, fish (especially gizzard shad, but including golden shiner, bullheads, and sunfish) represented about 65% of the adult diet, with crayfish (important diet item from March – June) constituting the majority of what remained; young bowfin (<102 mm, 4 in) consumed mainly water fleas and other microscopic animals (Plieger 1975). Pearse (1918) examined Wisconsin specimens and reported food items of fish remains (90.1%) and crayfish remains (9.4%). Cahn (1927) reported that the diets of southern Wisconsin populations consisted of fish (including small specimens of largemouth and smallmouth bass as along with yellow perch) and crayfish (dominant item in late summer and fall). In the Kissimmee River, Florida, species fed on herpetofauna (Jordan and Arrington 2001).
Growth and population structure: Early growth is rapid (Wallus et al. 1990). In southeast Missouri, fish are about 178-229 mm (7-9 in) long by the end of the first year, and attain a length of about 508 mm (20 in) when 5 or 6 years old (Pflieger 1975). In Louisiana, sex ratio of females to males was 2.3:1; females were longer and heavier than males (Davis 2006).
Phylogeny and morphologically similar fishes:
Only living representative of Amiiformes (Burgess and Gilbert 1980).
Numerous parasites listed by Hoffman (1967): Trematoda, Cestoda, Nematoda, Acanthocephala, Leech, Crustacea, Linguatula.
Commercial or Environmental Importance:
Status of species as “living fossil”, ease of maintenance, and interesting physiological and behavioral attributes has lead to its common use as a laboratory test animal (Burgess and Gilbert 1980). Due to its predatory nature, species has been considered a valuable tool in managing sport fish populations (Wallus et al. 1990). In Louisiana, eggs are marketed as less expensive caviar under the name "Choupiquet Royale" (Arceneaux 1992). Nests constructed by bowfin may be used for spawning by the golden shiner (Katula and Page 1998).
Arceneaux, H. 1992. Mining golden eggs from choupique. La. Conserv. (March/April):8-10.
Balon, E.K. 1975. Reproductive guilds of fishes: a proposal and definition. Journal of the Fisheries Research Board of Canada 32:821-864.
Bettoli, P.W., M.J. Maceina, R.L. Noble, and R.K. Betsill. 1993. Response of a reservoir fish community to aquatic vegetation removal. North American Journal of Fisheries Management 13:110-124.
Breder, C. M. and D. E. Rosen. 1966. Modes of reproduction in fishes. T.F.H. Publications, Jersey City, New Jersey. 941pp.
Burgess, G.H., and C.R. Gilbert. 1980. Amia calva (Linnaeus), Bowfin. pp. 53 in D. S. Lee, et al. Atlas of North American Freshwater Fishes. N. C. State Mus. Nat. Hist., Raleigh, i-r+854 pp.
Cahn, A.R. 1927. An ecological study of southern Wisconsin fishes. The brook silversides (Labidesthes sicculus) and the cisco (Leucichthys artedi) in their relation to the regions. Illinois Biological Monographs 11(1):1-151.
Carlander, K.D. 1969. Handbook of Freshwater Fishery Biology. Volume 1. The Iowa State University Press, Ames. 752 pp.
Cook, F.A. 1959. Freshwater fishes in Mississippi. Mississippi Fame and Fish Commission, Jackson. 239 pp.
Davis, J.G. 2006. Reproductive biology, life history and population structure of a bowfin Amia calva population in southeastern Louisiana. M.S. Thesis, Nicholls State University, Thibodaux. 83 pp.
Gelwick, F.P., and R.Y. Li. 2002. Mesohabitat use and community structure of Brazos River fishes in the vicinity of the proposed Allens Creek Reservoir. Report to the Texas Water Development Board. 50 pp.
Goldstein, R.M., and T.P. Simon. 1999. Toward a united definition of guild structure for feeding ecology of North American freshwater fishes. pp. 123-202 in T.P. Simon, editor. Assessing the sustainability and biological integrity of water resources using fish communities. CRC Press, Boca Raton, Florida. 671 pp.
Green, O. L. 1966. Observations on the culture of the bowfin. Prog. Fish-Cult. 28:179.
Greenbank, J. 1956. Movement of fish under ice. Copeia 1956(3):158-162.
Heufelder, G.R. 1982. Family Amiidae, bowfins. pp. 56-62. In N.A. Auer (ed.). 1982. Identification of larval fishes of the Great Lakes basin with emphasis on the Lake Michigan drainage. Great Lakes Fishery Commission, Ann Arbor, MI 48105. Special Pub. 82-3:744 pp.
Hildebrand S.F. and I.L. Towers. 1928. Annotated list of fishes collected in the vicinity of Greenwood, Mississippi, with descriptions of three new species. Bull. U.S. Bur. Fish. 43(2):105-136.
Hoffman, G.L. 1967. Parasites of North American Freshwater Fishes. University of California Press, Berkeley. 486 pp.
Hubbs, C. 2002. A preliminary checklist of the fishes of Caddo Lake in northeast Texas. Texas Journal of Science 54(2):111-124.
Hubbs, C., R J. Edwards, and G.P. Garrett. 1991. An annotated checklist of the freshwater fishes of Texas, with keys to identification of species. The Texas Journal of Science, Supplement 43(4):1-56.
Jordan, F., and D.A. Arrington. 2001. Weak trophic interactions between large predatory fish and herpetofauna in the channelized Kissimmee River, Florida, USA. Wetlands 21(1):155-159.
Katula, R.S., and L.M. Page. 1998. Nest association between a large predator, the bowfin (Amia calva), and its prey, the golden shiner (Notemigonus crysoleucas). Copeia 1:220-221.
Linam, G.W., J.C. Henson, and M.A. Webb. 1994. Fisheries inventory and assessment of Allens Creek and the Brazos River, Austin County, Texas. River Studies Report No. 12. Texas Parks and Wildlife Department, Austin. 13 pp.
Linnaeus, C. 1766. Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Laurentii Salvii, Holmiae, 12th ed., Vol. 1(1):532 pp.
Mansueti, A.J., and J.D. Hardy, Jr. 1967. Development of Fishes of the Chesapeake Bay Region. Port City Press, Baltimore, Maryland. 202 pp.
Miller, R.J., and H.W. Robison. 2004. Fishes of Oklahoma. University of Oklahoma Press, Norman. 450 pp.
Neill, W.T. 1950. An estivating bowfin. Copeia 1950(3):240.
Page, L.M., and B.M. Burr. 1991. A Field Guide to Freshwater Fishes of North America, north of Mexico. Houghton Mifflin Company, Boston, Massachusetts. 432 pp.
Pearse, A.S. 1918. The food of the shore fishes of certain Wisconsin lakes. Bulletin of the Bureau of Fisheries 35:245-292.
Pflieger, W.L. 1975. The Fishes of Missouri. Missouri Department of Conservation, Jefferson City. 343 pp.
Ross, S.T. 2001. The Inland Fishes of Mississippi. University Press of Mississippi, Jackson. 624 pp.
Scott, W.B., and E.J. Crossman. 1973. Freshwater Fishes of Canada. Fisheries Research Board of Canada, Ottawa. Bulletin 184:966.
Simon, T. P. 1999. Assessment of Balon’s reproductive guilds with application to Midwestern North American Freshwater Fishes, pp. 97-121. In: Simon, T.L. (ed.). Assessing the sustainability and biological integrity of water resources using fish communities. CRC Press. Boca Raton, Florida. 671 pp.
Trautman, M.B. 1957. The Fishes of Ohio. Waverly Press, Inc., Baltimore, Maryland. 683 pp.
Vessel, M.F., and S. Eddy. 1941. A preliminary study of the egg production of certain Minnesota fishes. Investigational Report No. 26.Minnesota Game Research Group. 18 pp.
Wallus, R., T.P. Simon, and B.L. Yeager. 1990. Reproductive biology and early life history of fishes in the Ohio River drainage. Volume 1: Acipenseridae through Esocidae. Tennessee Valley Authority, Cattanooga, Tennessee. 273 pp.
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