– Livebearers

There are four different types of livebearers that are quite popular with novice aquarists:

the guppy: Poecilia

the molly: Poecilia

the platy: Xiphorus

the swordtail: Xiphorus

There are other livebearers available, but they are nowhere as common as these four types in the local pet store.  The common guppy has become much more fancy than the common guppy that has been used for mosquitoe control in tropical bodies of water where the larvae are a main source of food.  There are now wide variations in both fin size and colour patterns.  Many of these two characteristics have been widely varied through selective breeding.  Because of this concentration on limited areas to highlight specific parts or colours, there has been quite a bit of interbreeding that has weakened many of the specimens available for sale.  Many first tanks have been started with guppies, but they really are not the best fish to try to cycle through a biological filter maturation.   Instead you should wait for the tank filters to mature before you try to add some guppies. pH should be close to neutral or slightly alkaline.

Mollies like much higher alkaline pH water, and they also like hard water.  I have seen salt water tanks started with black mollies.  They seem to adapt to sudden introduction into a marine aquarium with little problem in adjustment.  They are closer to brackish water fish than many others and thrive best with a fair bit of salt in the water.  They can be vulnerable to quite a number of problems if there is not enough salt or hardness available.  They offer a few different interesting colour variations and are generally some of the largest livebearers commonly kept in the starting aquarium.  Although they are not a favorite of mine, they can be interesting in larger aquariums with hard water conditions.  Because of their peculiar taste in water as compared to most beginning aquariums, the molly is not one of the fish I wuld attempt to start a new tank on it beak-in period.

In my opinion, the platy and swordtail are closely related, they live well together and provide a wide variety of assorted colour variations for the new aquarium.  The basic colours are in the reds, oranges and pastel blues. I prefer to use these types to add the bright reds that flash through the aquarium as they move. While platies do provide suitable action, and rarely are just sitting around, they are often more passive than the darting swordtails.  If I must start an aquarium, the use of a platy would be my choice, they seem to be hardiest of the group and best able to withstand the problems a new aquarium installation offers.

Livebearers males are very active. In most cases, one male can simply wear out a single female through his constant attention. For that reason, many of the above livebearers should be purchased in trios.  One male and two females. Although the females are often less colourful and patterned than a male, it is still wise to allow them a chance when confronted by an amorous male. 

The real true attraction of the livebearer is the fact that the mother gives birth to live fry. 

Many people of my generation had their first introduction to responsibility for life and a lesson on reproduction from these little fish.  The livebearers are the only species commonly kept that can offer this advantage and object lessson on life. No wonder they are so popular in every pet store.  Give the tank a good growth of fine leafed cover plants and the babies can be born and grow up in the the same aquarium where they were born.  They are ready to eat and swim right after birth.   They better  be, because they immediately become a tasty snack if the others in the tank can find them. This includes the new mother, who rapidly seems to forget giving birth and will eat right along with the rest of the tank.