Xiphophorus helleri
green swordtail
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Type Locality
Etymology/Derivation of Scientific Name
Synonymy
Characters
Maximum size: Known SL
78 mm (Miller et al., 2005).
Coloration: Males are
mostly greenish, with the longitudinal stripes of reddish, blue or duller
colors, and there may be rows of reddish spots in the dorsal fin. Females
are similar in color, nut lack the sword and have a normally expanded anal
fin. (Stevenson 1976). Quite variable, not normally showing pale
iridescent-blue pigment between red striped on side (Rauchenberger 2005).
Counts: Dorsal fin
rays 11-17, typically 12-14 (Minckley 1973).
Body shape:
Mouth position:
External morphology:
Lower caudal rays of male elongated into a "sword" (Hensley and Courtenay
1979) Males are easily recognized by the long sword-like process from the
ventral lobe of the caudal fin (Stevenson 1976). Claw present at tip of
gonopodial ray 5a (Rauchenberger 2005).
Distribution (Native and Introduced)
U.S. distribution:
Established in Montana, Florida, Arizona, California and Nevada. (Hensley
and Courtenay 1979) Hawaii and Canada (Dawes 1991; Jacobs 1969)
Texas distribution:
Abundance/Conservation status (Federal, State, NGO)
Habitat Associations
Macrohabitat: Diverse,
including ponds, springs, shaded and sometimes very rocky arroyos, ditches,
open lagoon and rivers with a variety of substrates; water clear to murky,
muddy, or opaque, sometimes badly polluted; currents non to moderate;
vegetation non to occasionally common; depth to 1.5m. (Miller et al., 2005).
Mesohabitat:
Biology
Spawning season: Young
8.0-14 mm SL have been collected between 23 December and 28 March,
suggesting a long reproductive season (Rauchenberger 2005). Possibly year
round (Milton and Arthington 1983).
Spawning habitat:
Spawning Behavior:
Live bearing, all poeciliid males posses a gonopodium. After attaining
sexual maturity, swordtails do not form mating pairs but are completely
polygamous (Tamaru et al., 2001).
Fecundity: known to be
as high as 242 fry/female (Breder and Rosen 1966), Spawns of X. helleri
average about 30 fry/female (Tamaru et al., 2001).
Age at maturation:
10-12 weeks, or at 25-30mm TL (Milton and Arthington 1983; Dawes 1991).
Migration:
Growth and Population
Structure: Younger swordtails grow at a rate of just over .5 mm/day. The
rate of growth slows after the fry attain sexual maturity. Accompanying
growth is a dramatic alteration in morphology most notable in males with the
extension of their caudal fin or "sword."
Longevity:
Food habits:
Omnivorous (Dawes 1991). Terrestrial and aquatic insects are eaten along
with phytoplankton and some macro algae (Arthington 1989).
Phylogeny and morphologically similar fishes
X. maculatus and X.
variatus are often used for hybridization in the aquarium trade for
obtaining ornamental species, because of their close relation. They are in
the same subfamily as Poecilia latipinna and P. reiculata
(Tamaru et al., 2001).
Host Records
Protozoa (Trichondina),
Monogenea (Dactlyogyrus and Gyrodactylidae) and Fungi (Saprolegnia) (Tamaru
et al., 2001).
Commercial or Environmental Importance
X. helleri and the
hybrids involving it are used in the aquarium trade worldwide (Tamaru et
al., 2001).
This popular aquarium fish
has been introduced in many places in Texas and elsewhere in the United
States. Such transfers are to be strongly discouraged as they often have
serious effects on native aquatic life (Miller et al., 2005).
References
Arthington, A.H. 1989. Diet of Gambusia affinis holbrooki, Xiphophorus
helleri, X. maculatus and Poecilia reticulata (pisces:
Poeciliidae) in streams of southeastern Queensland, Australia. Asian
Fisheries Science, (2) 193-212.
Breder, C. M. and D. E. Rosen. 1966, Modes of reproduction in fishes. New
York: American Museum of Natural History Press.
Dawes, J. A. 1991. Livebearing Fishes. A Guide to Their Aquarium Care,
Biology and Classification. Blandforn, London, England. 240 pp.
Heckel, J. 1848. Eine neue gatting poecilien mit
rochenartigen anklammerungs-organe. Sitzber. K. Akad. Wiss. Wien. Math. Nat.
Cl. 1:289-303.
Hensley, D.A. and W.R. Courtenay, Jr. 1980. Xiphophorus hellerii (Heckel)
Green swordtail pp. 554 in D.S. Lee et al. Atlas of North American
Freshwater fishes. N.C. State Mus. Nat. Hist., Raliegh, i-r+854
Jacobs, K. 1969. Livebearing Aquarium Fishes. The Macmillan Company. New
York.
Miller, R. R., W. L. Minckley and S. M. Norris. 2005. Freshwater Fishes of
Mexico. The University of Chicago Press. Chicago, IL. pp 258-59
Milton, A. A. and A. H. Arthington. 1983. Reproductive Biology of
Gambusia affinis holbrooki (Baird and Girard), Xiphophorus helleri,
(Gunther) and X. malculatus (Heckel) (Pisces; Poeciliidae) in
Queensland, Australia. Journal of Fishery Biology., (23): 23-41
Minckley, W. L. (1973). Fishes of Arizona. Phoenix, Arizona Game and Fish
Department 293 pp.
Rauchenberger, M. 2005. Artificial Key to Mexican Poeciliidae. pp. 212-218
in Miller et al., 2005. Freshwater Fishes of Mexico. The University
of Chicago Press. Chicago, IL.
Stevenson, H.M.1976. Vertebrates of Florida. University Presses of Florida,
Gainesville pp.1-607.
Tamaru, C. S., B. Cole, R. Bailey, C. Brown and H. Ako. 2001. A Manual for
Commercial Production of the Swordtail, Xiphpophorus helleri. CTSA
Publication Number 128. December 2001.
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