Beginners Guide - Live Bearers.

The family Poeciliidae contains Guppies, Mollies, Platies, and many other fishes. While these fish are often thought of as beginners' fish they have been intentionally left off the list until now in order to make a point.

The reasons these fish are often sold to beginners are that they are cheap, brightly colored, and have a general reputation among non-aquarists as easy fish. Notably absent from this list is any real suitability for keeping by beginners.

For one thing, many livebearers need high level of salt in their water to be healthy - making them incompatible with many other aquarium fish. Many common livebearers also are overbred, resulting in fish not nearly as healthy as those kept by aquarists of previous generations (or by the authors of most books).

Some are not even able to reproduce without human intervention. Finally, due to their low market price, they are generally not well cared for and may carry diseases.

Poeciliids, as they are also called, come from the Americas, primarily Central America. They are called "livebearers'' (as opposed to "egg-layers'', as all the previously discussed fish have been) because the eggs are fertilized within the female and the fry do not appear until the eggs have hatched. There are also livebearers from other families in which the details of reproduction vary.

The well-known Guppy can be found in a number of colors and with as many as 12 different artificial tail varieties. Also available is the closest thing that you may find to the wild Guppy - Poecilia reticulata: "feeder Guppies'' which are not bred for color. The fancy strains tend to be fragile while common Guppies often carry diseases. Guppies should be kept in water with at least one teaspoon of salt per five gallons of water.

Common Mollies are the Black Molly (which was derived from the Marled Molly - Poecilia sphenops) and the Sail-Fin Molly - Poecilia velifera (of which there are also several color varieties available). Black Mollies need at least one teaspoon of salt per five gallons of water to keep them healthy and prevent the outbreak of (Ichthyophthirius multifiliis, a parasite commonly seen in aquaria) while Sail-Fin Mollies need at least three times this amount. Sail-Fins grow to 6" while Black Mollies stay less than 3".

Closely related, Swordtails - Xiphophorus helleri and Platies - Xiphophorus maculatus are also popular fish. A number of color and finnage varieties are available of each with some of the Platies also referred to as "Moons''. These fish need at least a teaspoon of salt per 5 gallons of water to be healthy. Some varieties are susceptible to various maladies (Tuxedo Swords often get tumors, for instance) and as with so many other fish the naturally colored fish are probably your best bets. "Green Swords'' (which are really multi-colored) are naturally colored X. helleri, but unfortunately wild morphs of Platies are not often seen. The Variegated Platy - Xiphophorus variatus is sometimes seen, however, and fills this role nicely.