Heterandria formosa (known as the least killifish, dwarf topminnow, mosqu or midget livebearer)[3] is a species of livebearing fish within the family Poeciliidae. This is the same family that includes familiar aquarium fishes such as guppies and mollies. Heterandria formosa is not as commonly kept in aquaria as these species. Despite the common name "least killifish", it belongs to the family Poeciliidae and not to one of the killifish families. H. formosa is one of the smallest fish species; the 1991 Baensch Aquarium Atlas listed it as the 7th smallest fish in the world,[4] and as of 2006[update] it remains the smallest fish species found in North America.[5][6]
Heterandria formosa is the only member of its genus found in the United States.[7] Its geographical range spans the southeastern United States, from South Carolina south to Georgia and Florida, and westward across the Florida Gulf Coast to Louisiana.[7][8] In recent years, this species has been collected in eastern Texas. It is recorded to occur along the western portion of the Sabine River basin, according to North American Native Fishes (NANFA).[9] It has also been collected as far west as Humble, TX in small sand pit ponds after the 2017 floods associated with hurricane Harvey. It is one of the few aquarium fishes that is endemic to North America.
Heterandria formosa live primarily in vegetated, slow moving or standing freshwater habitats, but this species also occurs in brackish waters.[8]
Descriptionedit
Heterandria formosa is one of the smallest fish and smallest vertebrates known to science.[7] Males grow to about 2 centimeters (0.8 inches), while females grow a little larger, to about 3 centimeters (1.2 inches).[7][10]
The fish is generally an olive color, with a dark horizontal stripe through the center of the body. There is also a dark spot on the dorsal fin and females also have a dark spot on their anal fin. Like most poeciliids, male anal fins are modified into a gonopodium (intromittent organ) that is used to deliver sperm and impregnate females during mating.
Like most poeciliids, H. formosa is a livebearer. The male uses his modified anal fin, or gonopodium, to deliver sperm to the female. The fertilized eggs grow within the female until they hatch, and the free-swimming young are released into the water. Heterandria formosa has an uncommon breeding strategy even among livebearers: rather than all of the young being released at once, as many as 40 fry are released over a 10- to 14-day period, but occasionally over a longer period.[4][7][10]
Inbreeding depressionedit
The effect of inbreeding on reproductive behavior was studied in H. formosa in at least one published work.[11] One generation of full-sib mating was found to decrease reproductive performance and likely reproductive success of male progeny. Other traits that displayed inbreeding depression were offspring viability and maturation time of both males and females.
Referencesedit
^NatureServe (2013). "Heterandria formosa". IUCN Red List of Threatened Species. 2013: e.T202395A18233162. doi:10.2305/IUCN.UK.2013-1.RLTS.T202395A18233162.en. Retrieved 20 November 2021.
^ abcFroese, Rainer; Pauly, Daniel (eds.) (2019). "Heterandria formosa" in FishBase. February 2019 version.
^Combest, Lisa. "North American Native fishes". North American Native Fishes Forum. North American Native Fishes. Retrieved 5 March 2018.
^ abDawes, J. (2001). Complete Encyclopedia of the Freshwater Aquarium. p. 276. ISBN1-55297-544-4.
^Ala-Honkola O, Uddström A, Diaz Pauli B, Lindström K (2009). "Strong inbreeding depression in male mating behaviour in a poeciliid fish". Journal of Evolutionary Biology. 22 (7): 1396–406. doi:10.1111/j.1420-9101.2009.01765.x. PMID 19486236.
External linksedit
"Heterandria formosa - Der Zwergkärpfling", German language
December 15, 2023
heterandria, formosa, known, least, killifish, dwarf, topminnow, mosqu, midget, livebearer, species, livebearing, fish, within, family, poeciliidae, this, same, family, that, includes, familiar, aquarium, fishes, such, guppies, mollies, commonly, kept, aquaria. Heterandria formosa known as the least killifish dwarf topminnow mosqu or midget livebearer 3 is a species of livebearing fish within the family Poeciliidae This is the same family that includes familiar aquarium fishes such as guppies and mollies Heterandria formosa is not as commonly kept in aquaria as these species Despite the common name least killifish it belongs to the family Poeciliidae and not to one of the killifish families H formosa is one of the smallest fish species the 1991 Baensch Aquarium Atlas listed it as the 7th smallest fish in the world 4 and as of 2006 update it remains the smallest fish species found in North America 5 6 Heterandria formosaAdult femaleConservation statusLeast Concern IUCN 3 1 1 Scientific classificationDomain EukaryotaKingdom AnimaliaPhylum ChordataClass ActinopterygiiOrder CyprinodontiformesFamily PoeciliidaeGenus HeterandriaSpecies H formosaBinomial nameHeterandria formosaGirard 1859 2 Contents 1 Range and habitat 2 Description 3 Diet 4 Breeding 5 Inbreeding depression 6 References 7 External linksRange and habitat editHeterandria formosa is the only member of its genus found in the United States 7 Its geographical range spans the southeastern United States from South Carolina south to Georgia and Florida and westward across the Florida Gulf Coast to Louisiana 7 8 In recent years this species has been collected in eastern Texas It is recorded to occur along the western portion of the Sabine River basin according to North American Native Fishes NANFA 9 It has also been collected as far west as Humble TX in small sand pit ponds after the 2017 floods associated with hurricane Harvey It is one of the few aquarium fishes that is endemic to North America Heterandria formosa live primarily in vegetated slow moving or standing freshwater habitats but this species also occurs in brackish waters 8 Description editHeterandria formosa is one of the smallest fish and smallest vertebrates known to science 7 Males grow to about 2 centimeters 0 8 inches while females grow a little larger to about 3 centimeters 1 2 inches 7 10 The fish is generally an olive color with a dark horizontal stripe through the center of the body There is also a dark spot on the dorsal fin and females also have a dark spot on their anal fin Like most poeciliids male anal fins are modified into a gonopodium intromittent organ that is used to deliver sperm and impregnate females during mating Diet editHeterandria formosa primarily eats aquatic invertebrates such as worms and crustaceans They also eat plant matter 8 Breeding editLike most poeciliids H formosa is a livebearer The male uses his modified anal fin or gonopodium to deliver sperm to the female The fertilized eggs grow within the female until they hatch and the free swimming young are released into the water Heterandria formosa has an uncommon breeding strategy even among livebearers rather than all of the young being released at once as many as 40 fry are released over a 10 to 14 day period but occasionally over a longer period 4 7 10 Inbreeding depression editThe effect of inbreeding on reproductive behavior was studied in H formosa in at least one published work 11 One generation of full sib mating was found to decrease reproductive performance and likely reproductive success of male progeny Other traits that displayed inbreeding depression were offspring viability and maturation time of both males and females References edit NatureServe 2013 Heterandria formosa IUCN Red List of Threatened Species 2013 e T202395A18233162 doi 10 2305 IUCN UK 2013 1 RLTS T202395A18233162 en Retrieved 20 November 2021 Nicolas Bailly 2010 Bailly N ed Heterandria formosa Girard 1859 FishBase World Register of Marine Species Retrieved May 29 2012 Common names of Heterandria formosa FishBase Retrieved May 29 2012 a b Baensch H 1991 Baensch Aquarium Atlas pp 592 593 ISBN 3 88244 050 3 Jason C Chaney amp David L Bechler 2006 The occurrence and distribution of Heterandria formosa Teleostei Poeciliidae in Lowndes County Georgia PDF Georgia Journal of Science 64 2 67 75 Archived from the original PDF on 2013 10 14 Bennett M G Conway K W 2010 An overview of North America s diminutive freshwater fish fauna Ichthyological Exploration of Freshwaters 21 1 63 a b c d e Dawes J 1995 Livebearing Fishes pp 186 187 ISBN 0 7137 2592 3 a b c Froese Rainer Pauly Daniel eds 2019 Heterandria formosa in FishBase February 2019 version Combest Lisa North American Native fishes North American Native Fishes Forum North American Native Fishes Retrieved 5 March 2018 a b Dawes J 2001 Complete Encyclopedia of the Freshwater Aquarium p 276 ISBN 1 55297 544 4 Ala Honkola O Uddstrom A Diaz Pauli B Lindstrom K 2009 Strong inbreeding depression in male mating behaviour in a poeciliid fish Journal of Evolutionary Biology 22 7 1396 406 doi 10 1111 j 1420 9101 2009 01765 x PMID 19486236 External links edit Heterandria formosa Der Zwergkarpfling German language Retrieved from https en wikipedia org w index php title Heterandria formosa amp oldid 1170981517, wikipedia, wiki, book, books, library,
