Compatibility:

Mollies are nice peaceful fish. Sometimes they will attempt to chase others around a bit, but do not hurt them in most instances. Mollies do best in a group with a few males and several females. Mollies are good tank mates for Swordtails, Platies, Angel Fish, Corydoras Catfish, Plecostomus, and bigger Tetras such as Black Skirts, Red Serpaes, and Silver Tips.

Molly Species: Key Points, Tips & Tricks

A freshwater fish, they can adapt to a variety of salt levels in an aquarium, up to and including pure saltwater. Marine Aquarists often use mollys to Cycle a new tank due to their salt tolerance and hardiness. It is a misconception that acclimation to a marine environment must be done slowly over a period of at least several days to allow their bodies time to adjust and minimize stress. Different varieties will interbreed, so don't mix and match different varieties if you want to maintain pure varieties. Mollies will live for between 3 and 5 years and can grow to 5". Rarely mollies live longer and grow bigger. There is an apparent myth in molly lore indicating that females may reverse their sex and become large males, This myth probably generated because late-maturing males are physically similar to females and grow to large size before beginning to mature. It can be noted, on occasions, molly fry began to pick off ich just like a cleaner fish. Available marine varieties include the Green Sailfin Molly (wild), Silver Sailfin Molly, Black Sailfin Molly, Dalmatian (Mottled) Sailfin Molly, Gold Sailfin Molly, Black Sphenops, Yucatan Mollies and others. The sailfin varieties tend to get larger than most others, - three to six inches long (7.5 - 15 cm), but are quite gentle with other fish. The Yucatan mollies tend to remain small, about two inches (5 cm). Mollies are not generally long lived due to their deep hybridizations. All varieties of mollies are livebearers meaning internal fertilization, and subsequent development of the eggs occurs inside the body of the female fish. The male livebearer has what is called a rod-like copulatory organ called a "gonopodium", situated on the lower belly area. (the gonopodium is a modification of the anal fin).

References

• Biological profile - Sailfin Molly