The Littlest Livebearer
Heterandria Formosa
Size: 3 cm -- Tank: 30 L ---pH: 7.5 ---Temp: 24°C ---Origin: Southeast USA
Article By:
David L. Hall
813 Williams Ave.
Madera, CA 93637
dahall@lightspeed.net
From the bayous of Louisiana to the swamps and ditches of Florida and north to the ponds of southeastern North Carolina the Least Killifish, Heterandria formosa, lives its life relatively unnoticed because of its diminutive size. Yet this little livebearer deserves to be noticed by aquarists as it is easily kept and requires little attention.
I have kept this little fish off and on for years and it has been one of my favorites because it is hardy and tolerates a variety of water conditions so it can be kept it many places with local water. Temperature is not a critical issue as with most native fish it tolerates a wide range of temperatures in its native range. In fact I once collected it in the Panhandle of Florida when it was so cold that the little fish froze to the net when lifted out of the water, but recovered quite nicely when I put it in the water in my collecting bucket! H. formosa does well in temperatures that most tropical fish prefer 65 to 80 degrees Fahrenheit.
I have collected the Least killie on several occasions in Florida and in a variety of locations from ditches in the panhandle to lakes in south central. In every instance they were most abundant in the aquatic vegetation. I believe plants are a must in the H. formosa tank so that the adults feel comfortable and that the babies can hide. During courtship the males can become quite aggressive toward other males as well as toward the females and so adequate cover should be provided. In good condition these fish breed often, like many livebearers, but the female Least killies give birth to several fry over a period of 3 to 4 days. Parents rarely eat their young and the babies will feed on infusoria found on algae, plants or snails.
This little livebearer should have a tank of its own unless a suitable tankmate can be found that will not eat them as the females rarely exceed 1 1/5 inches and the males are only about 4/5 of an inch. Filtration is not critical because H. formosa is usually often found in locations with low oxygen levels. Regular water changes are highly recommended and are beneficial to the health of the fish.
These are not beautiful fish but are far from ugly. They are olive-gray with a broad black stripe running the length of the fish. The black spots on the dorsal and anal fins are very conspicuous and occasionally one can find a mottled form. It has been reported that H. formosa has been found with red spots and some take on a light golden hue.
The Least killie is an easy fish to keep and an easy fish to breed. It would be a good fish to use to introduce aquarists to the joys of native fish keeping. I believe as more people discover this little livebearer he will become a favorite of others. If you haven't tried H. formosa you are in for a treat.
I have kept this little fish off and on for years and it has been one of my favorites because it is hardy and tolerates a variety of water conditions so it can be kept it many places with local water. Temperature is not a critical issue as with most native fish it tolerates a wide range of temperatures in its native range. In fact I once collected it in the Panhandle of Florida when it was so cold that the little fish froze to the net when lifted out of the water, but recovered quite nicely when I put it in the water in my collecting bucket! H. formosa does well in temperatures that most tropical fish prefer 65 to 80 degrees Fahrenheit.
I have collected the Least killie on several occasions in Florida and in a variety of locations from ditches in the panhandle to lakes in south central. In every instance they were most abundant in the aquatic vegetation. I believe plants are a must in the H. formosa tank so that the adults feel comfortable and that the babies can hide. During courtship the males can become quite aggressive toward other males as well as toward the females and so adequate cover should be provided. In good condition these fish breed often, like many livebearers, but the female Least killies give birth to several fry over a period of 3 to 4 days. Parents rarely eat their young and the babies will feed on infusoria found on algae, plants or snails.
This little livebearer should have a tank of its own unless a suitable tankmate can be found that will not eat them as the females rarely exceed 1 1/5 inches and the males are only about 4/5 of an inch. Filtration is not critical because H. formosa is usually often found in locations with low oxygen levels. Regular water changes are highly recommended and are beneficial to the health of the fish.
These are not beautiful fish but are far from ugly. They are olive-gray with a broad black stripe running the length of the fish. The black spots on the dorsal and anal fins are very conspicuous and occasionally one can find a mottled form. It has been reported that H. formosa has been found with red spots and some take on a light golden hue.
The Least killie is an easy fish to keep and an easy fish to breed. It would be a good fish to use to introduce aquarists to the joys of native fish keeping. I believe as more people discover this little livebearer he will become a favorite of others. If you haven't tried H. formosa you are in for a treat.
