Speckled Mosquitofish, Phalloceros caudimaculatus (Hensel 1868)


Other Names: Dusky Millions Fish, One-spot Livebearer, Speckled Livebearer
Summary:
A yellowish mosquitofish with a black blotch on the caudal peduncle edged with silver or gold in some individuals. Males are speckled with black spots and blotches and have a black margin on the dorsal fin.

Cite this page as:
Gomon, M.F. & Bray, D.J. 2020, Phalloceros caudimaculatus in Fishes of Australia, accessed 29 Mar 2024, https://fishesofaustralia.net.au/home/species/2102

Speckled Mosquitofish, Phalloceros caudimaculatus (Hensel 1868)

More Info


Distribution

Native to South America between Brazil and Uruguay, and introduced to Australia via aquarium releases. The species has been recorded from the Perth region, Western Australia, Trephina Gorge, East MacDonnell Ranges, east of Alice Springs, Northern Territory, south of Adelaide, South Australia, Sydney, New South Wales, and the Lake Eyre drainage, central Australia (apparently unsuccessful release). The Sydney population, which was discovered at Long Reef Golf Course in 2002, was subsequently eradicated. 

The species was also found in South Australia and was succesfully eradicated. 

In Australia the species occurs in freshwater swamps and drains in metropolitan areas, usually amongst dense aquatic vegetation. Speckled Mosquitofish are very hardy and tolerate a wide range of environmental conditions, including cold water temperatures.

Features

Dorsal fin 7-8; Anal fin 9-10; Pectoral fin 10; Pelvic fin 5; Mid-lateral scales 28-30.

Body stout with a deep rounded belly (particularly in females, and more so when carrying a brood of young); upper surface flattened, especially the head; mouth small, upturned and protrusible, lower jaw a little longer than upper; eyes large; jaw with compressed, marginal jaw teeth.

Scales relatively large; lateral line absent
A single short-based, high, rounded dorsal fin, positioned well back on the trunk; anal fin small and rounded in females, elongate and modified into a gonopodium in males; caudal fin rounded.

Size

Females to 6 cm, males to 2.5 cm.

Colour

Yellowish overall with a black blotch on caudal peduncle edged with silver or gold. Males are speckled with black spots and blotches and have a black margin on the dorsal fin.

Feeding

Omnivores -  feed on plant material, detritus and aquatic invertebrates.

Biology

A live bearer that breeds at a very small size and has an extended breeding season. Both sexes mature at about 1.8 cm SL, and females produce broods of up to 80 young after a gestation period of about 24 days.

Fisheries

The species is listed as a Class 2 noxious species in NSW under the Fisheries Management Act 1994. Buying and selling Speckled Mosquitofish, or keeping them in garden ponds or farm dams, without a permit is illegal in NSW. Heavy penalties apply for breaking the rules.
Speckled Mosquitofish may still be maintained in fully enclosed aquaria.

Conservation

Speckled Mosquitofish may pose a serious threat to native fishes and frogs if populations were to expand and become established in other areas through aquarium releases. 

Etymology

The specific name caudimaculatus is from the Latin cauda (= tail) and maculatus (= spotted), in reference to the spot on the caudal peduncle of some specimens.

Species Citation

Gerardinus caudimaculatus Hensel, 1868, Arch. Naturg. 34: 362. Type locality: Costa da Serra, São Leopoldo, Brazil.

Author

Gomon, M.F. & Bray, D.J. 2020

Resources

Atlas of Living Australia

Speckled Mosquitofish, Phalloceros caudimaculatus (Hensel 1868)

References


Allen, G.R. 1989. Freshwater fishes of Australia. T.F.H. Publications, Inc., Neptune City, New Jersey.

Allen, G.R., Midgley, S.H. & Allen, M. 2002. Field guide to the freshwater fishes of Australia.  Perth : Western Australian Museum 394 pp.

Arthington, A.H. & Lloyd, L.N. 1989. Introduced poeciliids in Australia and New Zealand. pp. 333-348 in Meffe, G.K. & Snelson, F.F. Jr. (eds). Ecology and evolution of livebearing fishes (Poeciliidae). Englewood Cliffs, New Jersey, USA: Prentice-Hall, Inc.

Corfield, J., Diggles, B., Jubb, C., McDowall, R.M., Moore, A., Richards, A. & Rowe, D.K. 2008. Review of the impacts of introduced ornamental fish species that have established wild populations in Australia. Prepared for the Australian Government Department of the Environment, Water, Heritage and the Arts. 277 pp. 

Hammer, M.P., Adams, M. & Foster, R. 2012. Update to the catalogue of South Australian freshwater fishes (Petromyzontida & Actinopterygii). Zootaxa 3593: 59–74 

Harris, J.H. 2013. 11. Fishes from elsewhere. pp. 259-282 in Humphries, P. & Walker, K. (eds). Ecology of Australian Freshwater Fishes. Collingwood, Victoria : CSIRO Publishing 423 pp.

Hensel, R. 1868. Beiträge zur Kenntnis der Wirbelthiere Südbrasiliens. Archiv für Naturgeschichte 34: 356–375.

Larson, H.K., Williams, R.S. & Hammer, M.P. 2013. An annotated checklist of the fishes of the Northern Territory, Australia. Zootaxa 3696(1): 1-293

Maddern, M. 2003: The distribution, biology and ecological impacts of three introduced freshwater teleosts in Western Australia. Unpublished Honours thesis, Murdoch University, Western Australia. 119 pp.

Maddern, M.G. 2007. The One-spot livebearer: another introduced ornamental fish in Australia. Fishes of Sahul 21(3&4): 342-347.

Maddern, M.G. 2008. Distribution and spread of the introduced One-spot Livebearer Phalloceros caudimaculatus (Pisces: Poeciliidae) in southwestern Australia. Journal of the Royal Society of Western Australia 91: 229-235.

McDowall, R.M. 1999. Further feral poeciliid fish in New Zealand fresh waters, with a key to species. New Zealand Journal of Marine and Freshwater Research 33: 673-682.

McNeil, D.G. & Wilson P.J. 2008. The speckled livebearer (Phalloceros caudimaculatus): A new alien fish for South Australia. South Australian Research and Development Institute (Aquatic Sciences), Adelaide. pp. 29 Publication number: F2008/000939-1. SARDI Research Report Series No. 316.

McNeil, D.G., Westergaard, S. & Hartwell, D. 2010. Preliminary investigations into the control of speckled livebearers (Phalloceros caudimaculatus). Report to Primary Industries and Resources South Australia – Biosecurity. South Australian Research and Development Institute (Aquatic Sciences), Adelaide. SARDI Publication No. F2010/000306-1. SARDI Research Report Series No. 452. 29 pp.  

McNeil, D.G., Thwaites L. & Westergaard, S. 2013. Effective Eradication off Speckled livebearer (Phalloceros caudimaculatus) from South Australia following establishment in Willunga Creek. Report to Biosecurity SA. South Australian Research and Development Institute, West Beach.  

Merrick, J.R. & Schmida, G.E. 1984. Australian Freshwater Fishes Biology and Management.  Sydney : J.R. Merrick 409 pp.

Morgan, D.L., Gill, H.S., Maddern, H.G. & Beatty, S.J. 2004. Distribution and impacts of introduced freshwater fishes in Western Australia. New Zealand Journal of Marine and Freshwater Research 38: 511–523.

Rayner, T.S. & Creese, R.G. 2006. A review of rotenone use for the control of non-indigenous fish in Australian fresh waters, and an attempted eradication of the noxious fish, Phalloceros caudimaculatus. New Zealand Journal of Marine and Freshwater Research 40: 477–486.

Rowley, J.J.L., Rayner, T.S. & Pyke, G.H. 2005. New records and invasive potential of the poeciliid fish Phalloceros caudimaculatus. New Zealand Journal of Marine and Freshwater Research 39: 1013–1022.

Trendall, J.T. & Johnson, M.S. 1981. Identification by anatomy and gel electrophoresis of Phalloceros caudimaculatus (Poeciliidae), previously mistaken for Gambusia affinis holbrooki (Poeciliidae). Australian Journal of Marine and Freshwater Research 32(6): 993-996 

Unmack, P.J. 2001. Fish persistence and fluvial geomorphology in central Australia. Journal of Arid Environments 49: 653-669

Wager, R. & Unmack, P.J. 2000. Fishes of the Lake Eyre catchment of central Australia. Department of Primary Industries Queensland Fisheries Service 88 pp.

Quick Facts


CAAB Code:37244002

Biology:Live-bearer

Habitat:Freshwater swamps, drains

Max weight:6 cm TL

Native:Introduced, invasive

Species Maps

CAAB distribution map