Swordtails - Xiphophorus helleri
| Scientific Name | English Common Name | French Common Name |
|---|---|---|
| Xiphophorus helleri | Gold Wagtail Swordtail | Porte-épée doré wagtail |
The scientific name, Xiphophorus helleri is a catchall for quite a number of variants that offers a swordtail for almost every aquarist interested in keeping a passive community in their home or office.
The most common, and popular swordtails are the assorted red sword varieties. They can be highlighted with black, and there are a variety of shapes of the sword is displayed.
The standard sword extends from the bottom of the tail, but there are bred variants that display a lyretail, this is where the "sword" appears on both the top and the bottom.
Only the males are able to sport the tell-tale sword. Female swords have at most, a small stub of a sword, nothing that come close to the spectacular appendages the males will develop as they grow.
The females are also often larger and bigger through the body. The males are sleeker, usually slimmer throughout. The female is thicker in the middle and often grows much larger when she is pregnant.
Like all the other livebearers, swordtails should be kept in groups of three, where there is a single male and a couple, or more, females. The male is constantly trying to spawn, so it is quite possible that the aggressive male can wear out a single female by his constant advances.
As mentioned there are some rather striking differences between the male and female as far as actual shape is concerned. But it is even simpler to sex a pair of almost any livebearer. The males have developed a specialized fin designed to swing forward and laterally to pass sperm packets to the female during spawning.
Once impregnated, the female will carry the developing fry during the standard gestation period, for about a month, 28 – 30 days. When the fry are ready, the female will drop the fry directly into the tank.
The fish drop as a ball and suddenly straighten out and are ready to swim and eat right away. The place they are born requires heavy cover for the babies to rapidly find and hide. Unless the babies are born into a hatching tank, the other inhabitants of the aquarium will have no problem with hunting and eating the new babies.
Unlike the other livebearers, when a large group of female swordtails are kept together for a period of time, it seems that a male will suddenly appear in the group. It seems that occasionally a female will suddenly change sex and become a male.
This is a unique characteristic with these fish, not something common to livebearers or other types of fish. This rare phenomenon will probably never occur in a home aquarium, the fish need to be rather young and basically kept in a crowded single sex aquarium for a female to change to male.
