Two male white and orange fish swimming next to each other.Livebearers are a staple of fish-keeping hobbyists around the world. They are generally very hardy and, because of their highly prolific nature, usually reasonably inexpensive. Size of enclosure is also less important since they do well in aquariums 55 gallons and larger, but many also do well in as small as a 5 gallon. Gender is easily distinguishable in Livebearers even at a young age because Males have an external organ called a Gonopodium located underneath on the pelvic area and trails back toward the Caudal (tail) Fin. Females are typically a little more round-bellied and will have Pelvic Fins there instead. Males often are more ornate with larger Caudal, or Dorsal (top) Fins too. It is important to note that mixed gender populations will breed constantly and all inhabitants will try to eat the Fry (baby fish), even the mother will sometimes turn around and consume them while birthing more! Breeder nets and traps are commercially available to help the aquarium owner in their conservation efforts. A lower percentage of males or even a single male in the population mix is recommended due to aggression from males both to each other and sexual persistence with females. If a Female is unable to escape constant breeding attempts, she could become stressed even to the point of death. It is also interesting to point out that female Livebearers will often harbor the male’s sperm for awhile and become pregnant later or even multiple times from a single mating! Livebearers typically inhabit the middle to top section of a tank but will venture to all parts.Male versus female fish diagram.

Many commercially available Livebearers are not found in the wild in the same way as you find in Tropical Fish Stores. Because of their prolific nature, many generations can be bred relatively quickly and numerous captive strains are now available to the hobbyist such as Fantail, Lyretail, and Hi-Fin to name a few along with a multitude of developed colors and patterns. The natural habitat for most Livebearers is in estuaries or bogs where freshwater runs into the ocean and in the aquarium this translates to a benefit in having salt present in their water. Since varying salt levels are the normal in the wild, it is not too important to retain an exact salinity level, but some Livebearers are more accustomed to higher levels of salt than others and acceptable ranges may differ as well.

Some Livebearer Fish that The Ocean Floor commonly or seasonally stock are:

  • Mollies
  • Platies/Variatus
  • Swordtails
  • Guppies
  • Halfbeaks
  • Gambusia or Mosquito Fish