Sorry to need to disagree with you ZephyrStarPlaties. Mollies are not brackish at all. They do tolerate a large variety of water conditions but can live equally well in water anywhere from full fresh to full salt water conditions. As it happens they represent a small group of fish that are truly euryhaline. They do not exhibit any real preference for salt or fresh water but tolerate both conditions equally well. Where that leaves us is with people like me who keep their mollies in purely fresh water while reef keepers use pet shop mollies to cycle their salt water tanks.
The pet shop mollies not only tolerate but thrive in a pure salt water setting. It may seem strange until we start to consider where mollies are found in the wild. Their most common location is at the mouth of a creek or river that discharges right into a salt water environment like at a river mouth. In that kind of environment, they must be able to readily adapt to different water conditions that they might encounter and that is exactly what we find them able to do. Do not confuse an ability to adapt to salt water as a necessity to only inhabit brackish conditions. These guys are truly adaptable and they have no need for brackish conditions but they also will not avoid such conditions or even pure salt water conditions. I really love my mollies and I admire their adaptability.
