Swordtails are a popular beginner's fish because of their hardiness and the ease with which they breed.  Swortails originally came from South America.  Although originally a drab olive green in appearance, they have been bred into a number of variations, such as the Tuxedo (black on the body), Lyretail (forked tail) and Red Swordtail.  They are closely related to the Platy, but differ in that they have the distinctive swordtail on the males.  In fact Swordtails and Platies can interbreed.  Swordtails like brackish water, so it is advisable to add about a teaspoon of salt for a 5 gallon aquarium.  They eat flake foods, but will enjoy live brine shrimp and bloodworms. More than one female should be kept with each male, to help reduce the stress on females from harassment by the male.  In addition to the sword tail, males have a gonopodium which is used to fertilize the female.  Females are larger and broader.  One fertilization can result in several sets of births.  When pregnant, females have a dark gravid spot near their anal fin.  Females can have young every 4 to 6 weeks.  They will seek an area of seclusion to give birth and can have anywhere from 10 to more than 50 young.  Swordtails will eat their young, so it is important to either have a heavy plant cove ...

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