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Sailfin Molly (Poecilia latipinna)


Department of Wildlife and Fisheries, Mississippi State University, Mississippi State, Mississippi, 39762, USA

  • Fig. 1. Sailfin Molly Characteristics: 1. Livebearer 2. Upturned mouth 3. Sexual dimorphism 4. Dorsal fin anterior to anal fin 5. Can be confused with mosquitofish and killifishes.
  • Fig. 2. Distribution of the Sailfin Molly (Poecilia latipinna)

Context & Content[+] Expand

Order Cyprinodontiformes, Family Poeciliidae.

General Characteristics[+] Expand

Poecilia latipinna is a livebearer with a small, superior mouth and a pointed head (see Figure 1). The body is laterally compressed changing from more robust near the anterior to flat nearest the caudal peduncle (Ross 2001). Larger fish are generally deeper bodied (Ross 2001). The caudal fin is rounded. In males, the anal fin is altered into a gonopodium (a modified structure for breeding) and the dorsal fin is greatly enlarged and sail-like. The second ray of the pelvic fin is also elongated in males (Ross 2001). Teeth are immoveable and are organized in multiple rows with the outer row being larger (Hubbs et al. 1991, Ross 2001). Sailfin mollies have 25-29 lateral line scales, 12-16 dorsal rays, 7-9 anal rays, and 6-7 pelvic rays (Hubbs et al. 1991, Ross 2001). Adult size can be widely variable but normally ranges from 16-103 mm Standard Length in males (Snelson 1985). The maximum size recorded is 150 mm Total Length (Burgess 1980).

Distribution[+] Expand

In Mississippi, P. latipinna are naturally found only in the coastal portions of the state in the Pearl, Coastal Rivers, and Pascagoula drainages (Ross 2001). They also occur in coastal waters and streams from North Carolina to Mexico (see Figure 2). P. latipinna have a wide environmental tolerance, and because of their popularity in the aquarium trade, P. latipinna has been introduced across the United States and internationally (Courtenay and Meffe 1989).

Form & Function[+] Expand

The origin of the dorsal fin is anterior to the origin of the anal fin, and the dorsal fin base is also more than half the predorsal length (Hubbs et al. 1991). Dark spots on the scales obscure a diamond shaped color pattern (Hubbs et al. 1991). The expanded dorsal fin of large male P. latipinna is highly distinctive. The dorsal fin is enlarged in males greater than 45 mm SL. Males from 30-45 mm SL show some enlargement of the dorsal fin. Males less than 30 mm SL do not develop an enlarged dorsal fin and usually resemble females (Snelson 1985). Larger breeding males typically have a reddish orange marginal band on the dorsal fin and a reddish orange spot on the caudal fin (Ross 2001). The caudal fin often has a dusky margin (Ross 2001). By exploiting the thin film of oxygen rich surface water with their upturned mouths, P. latipinna are able to survive oxygen depleted habitats (Ross 2001).

Small males, females, and juveniles could be confused with mosquitofishes (Gambusia affinis) or with small topminnows, including the rainwater killifish (Lucania parva). P. latipinna differs from both in having distinct horizontal rows of spots expressed laterally, and differs from all killifishes by having internal fertilization (males possess a gonopodium to impregnate females). P. latipinna differs from mosquitofishes in lacking a distinct teardrop marking under the eye (Ross 2001).

Ontogeny & Reproduction[+] Expand

P. latipinna are live-bearers; courtship and copulation occur rapidly. Young are born live, not hatched from deposited eggs. Maturation occurs quickly; males born in spring may breed in late summer; more often, fish grow and do not breed until next spring (Snelson 1984). Sex can normally be determined when individuals reach a length of 1.6 to 1.8 cm TL (Snelson and Wetherington 1980). Large males (over 45 mm SL) use brightly-colored, enlarged dorsal fins to attract females (Snelson 1985). In Florida, P. latipinna breeds from April — June, and again from August — October (Snelson 1984). As with all livebearers, the optimal temperatures for reproduction are reported to be between 22 and 26 C (Dawes 1991). Reproductive patterns in the state of Mississippi are not well known.

Broods typically range from 6-36, depending upon the size of the female (Ross 2001). Very large females can produce up to 141 young in a brood (Moyle 1976). Broods are produced every 21-68 days depending on time spent in egg development, and the rate at which egg yolk is added (Trexler 1985, Snelson et al. 1986). Females are capable of storing sperm for an extended period of time (Moyle 1976, Burgess 1980). Populations are comprised of females, dominant males, and small "sneaky" males (Snelson 1982). Studies have shown that females prefer larger males when presented with several mates simultaneously (MacLaren and Rowland 2006). These larger males frequently engage in territorial courtship displays, and smaller males must "sneak" in to inseminate females without courtship in order to be reproductively competitive (Farr et al. 1986, Travis et al. 1990, Travis 1994, Travis and Woodward 1989). Males appear to suffer higher rates of mortality, a consequence of their life spent largely in a breeding frenzy. Males greater than 45 mm SL are generally found in less dense populations; at higher population densities, males are usually smaller than 45 mm SL (Snelson 1985). Males may only live 11 months or less upon reaching sexual maturity (Snelson 1982).

Ecology[+] Expand

Principal habitats are stream and pond edges near vegetation for food and protection (Ross 2001). P. latipinna are often found in stagnant or low-flow areas. Studies have shown that individuals can become acclimated to hypoxic conditions, with dissolved oxygen concentrations as low as 1 mg/L (Timmerman and Chapman 2004). The ability to tolerate hypoxic conditions is also due to the larger gill surface area found in natural populations that inhabit low oxygen waters.

P. latipinna reportedly live in small shoals, or groups, comprised of 10-20 individuals of both sexes (Aspbury 2007). Females generally outnumber males (Moyle 1976). Early in life, growth rates are similar for both sexes but male growth rates generally decline with onset of sexual maturity (Snelson 1982).

The thermal tolerance of P. latipinna has been documented from approximately 6 to 40 C, and depends somewhat upon the temperature to which the individual was previously acclimated (Fischer and Schlupp 2009). P. latipinna is one of only a few species of bony fishes considered to be truly euryhaline, inhabiting fresh to hypersaline waters (Nordlie et al. 1992, Zedler 2001). Populations have tolerated salinities up to 80 ppt, depending on the salinity to which the fish were previously acclimated (Nordlie et al. 1992). An even wider salinity range of 0 to 94.6 ppt has been documented in other studies (Kumaraguru Vasagam et al. 2007). Captive breeding of P. latipinna is reportedly least successful in freshwater (Kumaraguru Vasagam et al. 2005). Salt is typically added to P. latipinna tanks to induce breeding and a salinity of 25 ppt yields faster growth and the greatest number of fry per clutch (Kumaraguru Vasagam et al. 2005).

Behavior[+] Expand

P. latipinna are omnivorous: feeding on green algae, diatoms and other plant material, as well as animal material like rotifers, small crustaceans, and aquatic insects. At times, they may heavily predate mosquito larvae and pupae. Larger fish eat more plant material (Harrington and Harrington 1961, Hunt 1953, Zedler 2001); invertebrates are eaten only when greatly abundant and are mainly consumed by smaller fish (Harrington and Harrington 1961).

Genetics[+] Expand

There is no information on the subject at this time

Conservation[+] Expand

Populations in southern drainages are currently stable (Warren et al. 2000).

Acknowledgements[+] Expand

I wish to thank Dr. E. Dibble and Dr. D. Jackson for feeding my passion to study fish and fisheries. I would also like to thank Buford Lessley for his advice and guidance regarding aquaria.

Remarks[+] Expand

There is no information on the subject at this time

Literature Cited[+] Expand

Aspbury, A. S. 2007. Sperm competition effects on sperm production and expenditure in sailfin mollies, Poecilia latipinna. Behav. Ecol. 18: 776-780.

Aspbury, A. S., and C. R. Gabor. 2004. Differential sperm priming by male sailfin mollies (Poecilia latipinna): Effects of female and male size. Ethology 110(3):193-202.

Burgess, G. H. 1980. Poecilia latipinna (Lesueur), Sailfin molly. P. 549 in D.S. Lee, et al. Atlas of North American Freshwater Fishes. N. C. State Mus. Nat. Hist., Raleigh, 854 pp.

Courtenay, W. R. and G. K. Meffe. 1989. Small fishes in strange places: a review of introduced Poeciliids. 319-331. In: Meffe, G. K. and F. F. Snelson, Jr., eds. Ecology and evolution of livebearing fishes (Poeciliidae). Prentice-Hall. Englewood Cliffs, NJ. USA.

Dawes, J. A. 1991. Livebearing fishes: A guide to their aquarium care, biology and classification. Blandford Publications. London, UK.

Farr, J. A., J. T. Travis and J. C. Trexler. 1986. Behavioral allometry and interdemic variation in sexual behavior of the sailfin molly Poecilia latipinna (Pisces: Poeciliidae). Anim. Behav. 34: 497-509.

Fischer, C. and I. Schlupp. 2009. Differences in thermal tolerance in coexisting sexual and asexual mollies (Poecilia, Poeciliidae, Teleostei). J. Fish Biol. 74: 1662-1668.

Harrington, R. W., Jr., and E. S. Harrington. 1961. Food selection among fishes invading a high subtropical salt marsh: from onset of flooding through the progress of a mosquito brood. Ecology 45(4):646-666.

Hubbs, C., R. J. Edwards, and G. P. Garrett. 1991. An annotated checklist to the freshwater fishes of Texas, with keys to identification of species. The Texas Journal of Science, Supplement, 43(4):1-56.

Hunt, B. P. 1953. Food relationships between Florida spotted gar and other organisms in the Tamiami Canal, Dade Country, Florida. Trans. Amer. Fish. Soc. 82(1952):12-33.

Kumaraguru Vasagam, K. P., S. Rajagopal and T. Balasubramanian. 2005. Effect of salinity on gestation period, fry production, and growth performance of the sailfin molly (Poecilia latipinna Lesueur) in captivity. Israeli J. Aquacul. 57: 147-152.

Kumaraguru Vasagam, K. P., A. Shanmugam and S. Rajagopal. 2007. Dietary effect of fry production and growth performance of sailfin molly, Poecilia latipinna, in salt water. Acta Ichthyol. Piscat. 37: 29-35.

MacLaren, R. D. and W. J. Rowland. 2006. Differences in female preference for male body size in Poecilia latipinna using simultaneous versus sequential stimulus presentation designs. Behav. 143: 273-292.

Nico, L., P. J. Schofield, and M. Neilson. 2013. Poecilia latipinna. USGS Nonindigenous Aquatic Species Database, Gainesville, FL. Revision Date: 9/29/2011. Accessed 3/28/2013.

Nordlie, F. G., D. C. Haney and S. J. Walsh. 1992. Comparisons of salinity tolerances and osmotic regulatory capabilities in populations of sailfin molly (Poecilia latipinna) from brackish and fresh waters. Copeia. 1992: 741-746.

Ross, S. T. 2001. The Inland Fishes of Mississippi. University Press of Mississippi. 624 pp.

Snelson, F. F., Jr. 1982. Indeterminate growth in males of the sailfin molly, Poecilia latipinna. Copeia 1982(2):296-304.

Snelson, F. F., Jr. 1984. Seasonal maturation and growth of males in a natural population of Poecilia latipinna. Copeia 1984(1):252-255.

Snelson, F. F., Jr. 1985. Size and morphological variation in males of the sailfin molly, Poecilia latipinna. Env. Biol. Fish. 13(1):35-47.

Snelson, F. F., Jr. and J. D. Wetherington. 1980. Sex ratio in the sailfin molly, Poecilia latipinna. Evolution. 34: 308-319.

Snelson, F. F., Jr., J. D. Wetherington, and H. L. Large. 1986. The relationship between interbrood interval and yolk loading in a generalized poeciliid fish, Poecilia latipinna. Copeia 1986(2):295-304.

Timmerman, C. M. and L. J. Chapman. 2004. Hypoxia and interdemic variation in Poecilia latipinna. J. Fish Biol. 65: 635-650.

Travis, J. 1994. The interplay of life-history variation and sexual selection in sailfin mollies. In: Real, LA, ed. Ecological genetics. Princeton University Press. Princeton, NJ. USA. 205-232.

Travis, J., J. C. Trexler, and M. Mulvey. 1990. Multiple paternity and its correlates in female Poecilia latipinna (Poeciliidae). Copeia. 1990: 722-729.

Travis, J. and B. D. Woodward. 1989. Social context and courtship flexibility in male sailfin mollies, Poecilia latipinna (Pisces: Poeciliidae). Anim. Behav. 38: 1001-1011.

Trexler, J. C. 1985. Variation in the degree of viviparity in the sailfin molly Poecilia latipinna. Copeia 19885(4):999-1004.

Warren, M. L. Jr., B. M. Burr, S. J. Walsh, H. L. Bart Jr., R. C. Cashner, D. A. Etnier, B. J. Freeman, B. R. Kuhajda, R. L. Mayden, H. W. Robison, S. T. Ross, and W. C. Starnes. 2000. Diversity, distribution and conservation status of the native freshwater fishes of the southern United States. Fisheries 25(10):7-29.

Zedler, J. B., ed. 2001. Handbook for restoring tidal wetlands. CRC Press LLC. Boca Raton, FL. USA. 458 pp.

Order[+] Expand

The Cyprinodontiformes is an order of ray–finned fish, comprising mostly small, fresh-water fish. Many popular aquarium fish, such as killifish and live-bearers, are included. They are closely related to the Atheriniformes and are occasionally included with them. A colloquial term for the order as a whole is toothcarps, though they are not actually close relatives of the true carps — the latter belong to the superorder Ostariophysi, while the toothcarps are Acanthopterygii.

Family[+] Expand

Poeciliidae is a family of fresh–water fish which are live–bearing aquarium fish (they give birth to live young). They belong to the order Cyprinodontiformes, tooth–carps, and include well–known aquarium fish such as the guppy, molly, platy, and swordtail. The original distribution of the family was the southeastern United States to north of Rio de la Plata, Argentina. However, due to release of aquarium specimens and the widespread use of species of the genera Poecilia and Gambusia for mosquito control, poeciliids can today be found in all tropical and subtropical areas of the world. In addition, Poecilia and Gambusia specimens have been identified in hot springs pools as far north as Banff, Alberta.

About This Project.

This website is an ongoing project by Ichthyology students of the Department of Wildlife, Fisheries, and Aquaculture, within the College of Forest Resources to provide information on the biology and ecology of fishes that occur in Mississippi. These accounts were written by undergraduate students as a course assignment, generally follow the format of Mammalian Species, and nomenclature follows Nelson 1994.

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