Poecild's files


  Mosquito Fish, Dwarf Top-Minnow, Dwarf Livebearer, Least Killifish, Lesser Killifish, Pygmy Livebearer


Heterandria formosa

an extract from the article Three Unusual Livebearers by Howard Norfolk. Original publication : Vancouver Aquatic Hobbyist Club Newsletter.
You can find the whole article here: http://www.aquarticles.com

H. formosa is not a killifish, but is in fact the smallest species of livebearer, and for that matter one of the smallest fish species in the World, and until recently was considered to be the smallest known vertebrate in the U.S.A. The males grow to 0.8", and the females 1.4".

They are tiny North American fish, found in weedy, slow moving fresh and brackish waters from Florida to North Carolina, and were recently also discovered in Texas. They are not normally found in pet stores, since they are so small and not too showy, being olive green in colour with a dark brown line running down the side of their body. Don't say I told you because it says so in the books, but the males proudly sport very large gonopodiums!

They accept all foods but should have some vegetable matter. I feed mine regular flakes and spirulina flakes, pinched to a small size. They are not greedy eaters and are rather lazy swimmers, and are best kept in a well planted small species tank at room temperature in hard, slightly alkaline water with some tannin. Both adults and young like to hide amongst plants.

The young are produced continually on a "production line" system ("superfoetation") rather than in distinct broods, and it is said that adult females can produce one or two fully developed young almost every day of their adult lives. I acquired a young pair from our member Matt Hennig a few months ago, and now have well over a dozen.

Despite being a North American fish, Matt's strain came from Germany. Having kept them before and liking them, Matt's father bought some in Germany and flew here with them in a bag in his shirt pocket, aerating the bag every now and then with a straw!

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