Originally Posted by
Z06 vette
http:///forum/post/3212687
I do not know about every individual mollie, but to say they don't see a drop of salt in their life might be an opinion. .
I didnt say none of them saw a drop I said most. and its not an opinion its actually a researched fact. I just reread that last sentance and it reads like its a snotty statement and I do not want you to take it that way, I am just trying to point out that its fact, not just my personal opinion that most mollies are freshwater in the wild and very few species live fully marine.
Quote from Neale monks article the truth about mollies.
Besides the fact that aquarium mollies aren’t any one species, muddying the waters yet further is the remarkable adaptability that mollies show in terms of environment. There really isn’t any one definitive “molly habitat”. Poecilia mexicana is found, for example, even in and around caves, where the waters are dark and rich in calcium sulphate. These cave-dwelling populations of Poecilia mexicana are pink and have relatively small eyes, but have highly developed taste receptors on the head and an enlarged lateral line system to compensate for the lack of light. Other mollies are found in estuaries and around mangroves, being well able to live in full-strength seawater without problems.
For the most part though, mollies are inhabitants of freshwater streams flowing across coastal plains. The water chemistry is typically hard and alkaline, pH 7.5 to 8.0 and hardness 15-30˚dH. Although water temperature may vary depending on geographical location, most mollies seem prefer warm water environments and are most common where the water temperature is around 25-28˚C (77-82˚F). These streams aren’t saline though, and while mollies certainly are found in brackish waters, that isn’t their primary habitat.
Mollies have been transported around the world and released into all kinds of environments. There are, for example, populations of mollies established in the marine Gulf of Thailand. Mollies have also become established in the United States in freshwater rivers and lakes far inland, where they can pose a serious threat to the survival of native fishes. In these cases, the mollies concerned are hybrids very like those kept by aquarists (in fact, in many cases they were descended from aquarium fish turned loose by careless aquarists and fish breeders). Because they are so similar to the aquarium fish, these feral mollies demonstrate quite clearly that while mollies can live in brackish and salt waters, they are just as able to survive in freshwater environments as well.
To salt, or not to salt, that is the question!
If mollies can live in freshwater in the wild, why do so many experienced aquarists recommend keeping them in brackish water? To understand this, it is important to realise that marine salt mix does more than simply raise the salinity.
Marine salt mix contains table salt plus a huge variety of other mineral salts, including a large quantity of salts that raise pH and increase hardness. The addition of marine salt to molly aquarium provides mollies with water chemistry much closer to that which they prefer and also acts as a buffer, inhibiting any subsequent water chemistry changes. Tonic salt can’t do this, because it contains nothing by sodium chloride, a chemical that doesn’t modify pH or hardness at all. An aquarist adding a certain amount of salt to the molly aquarium is effectively guaranteeing the correct water conditions without any need to mess about with pH buffers or water hardening agents.
there is more to it the whole article is quite educational. with further research you can actually find that there are several (I think three or four) species that tolerate full salt the best, while others are only able to fully thrive in fresh to brackish waters.