mollies in fresh or brackish?

[Shadowraven]

Keep in mind thought that some fish DO NOT do well with salt in the tank. Most scaleless catfish for example. Put salt into a tank with Corydoras and you may kill them. I have screwed up and put salt in with corys before, but very little. It did not kill them, but they did not look like happy campers.

 

[fishguy1]

Moved from elsewhere:

If they thrived in such conditions, then they wouldn't be so sparsely found in them.

Do you know for a fact that is true or are you assuming it is? I also don't see any sheep wandering the streets. Does that mean they wouldn't do well there or are there other factors involved?

Looks like all the posts didn't make it to the new thread. Someone else had made the comment about them being sparsely found in brackish water. As I originally said, I don't profess to know where they are found since I don't care. I was making a case based on logic and reasoning - if they THRIVED in such conditions, then wouldn't you expect to find them in those conditions more regularly?

Yes, you don't see sheep wandering the streets because that is not an environment that suits them. I'm not a sheep herder, but I would venture to say that the reason sheep are often seen in fields eating grass is because sheep do best in fields eating grass.....not wandering streets.

Predation is a weak point - all fish are subject to predation no matter where they live. That's nature. If a population of fish is struggling to maintain a foothold in a particular region, for ANY reason, then I'd hardly say it's thriving.

Again, I don't know how common mollies are in brackish and marine environments and I don't care. But if it's true that they are rarely found in such environments, then I don't know how anyone could say they are thriving in it. Thriving would be a growing, sustainable population.

 

[Shadowraven]

Possibly, but you missed the point I was making there. They wouldn't occur and breed in those environments, if they had not evolved to be able to live there. I have never witnessed, or read of, any of these fish being in distress in a brackish tank. Just the opposite actually. They have always thrived in any brackish set-up I have seen them in. It may not be their primary habitat, but they still do well in it.

Feral mollies have also managed to establish themselves in the marine Gulf of Thailand.

Lets keep in mind though that when we are talking about saltwater, we mean marine salt, not table or tonic salt. Mollies will always prefer marine salt. A 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. Mollies prefer hard, alkaline water and this matches what they prefer very well.

Just because you don't find them filling the waters like flies, it hardly means that they are struggling. Sparse can mean many things, such as not widespread, but concentrated in some areas.

I may say that the flies sure seem to be rare anymore, when there is a new pig farm not 100 feet away. That doesn't mean that the flies are struggling, it just means that they aren't where I'm looking right now.

Sometimes when you are fishing, you don't see many fish. Does that mean the fish in it are struggling, or that I'm just in the wrong part of the lake?

As for predation, that is NOT a weak point. Some mollies may have actually migrated to a brackish habitat to avoid predators. Just because mollies can adapt to saltwater, it does not follow that their predators can as well. New waters mean new challenges and different animals. That is one of the prime reasons animals move to new locations. To exploit new sources of food and to avoid predation.

 

[Fishguy2727]

Scalation doesn't effect ability to tolerate salt. If so then cories and plecos would be able to tolerate much higher salinities because their scales are so much thicker. This is a myth that keeps getting repeated. Salt and meds get in through the gills, so it doesn't matter how thick the scales are, the salt will get in.

With mollies it is at least arguable, but other freshwater fish are definitely freshwater and should not have salt added all the time. Fish like cories come from Amazonia, the softest body of water on Earth, should not get salt all the time. They should only get salt short term when stressed or to treat specific known problems. These are FRESHwater fish, keep them that way.

 

[Fishguy2727]

If you are going by fishbase it also says freshwater, so based on that they should be in fresh just as much as they should be in brackish. But even fishbase states freshwater first.

It keeps getting overlooked that no one is saying they can't go in brackish. No one is arguing that they can't live in it long term and even breed very well. The only issue was whether or not it is better for them (and their kidneys and other internal organs) to be in fresh or brackish long term.

There are only two times this even matters. One is if you only have mollies in a tank and want to know which is better. The other is if you have a brackish tank and want to know if you can add mollies safely. If there are ANY other freshwater fish in the tank, whether you think mollies are or not, the tank should not get salt. Freshwater fish will develop kidney and other problems if kept in salted water long term.

 

[jenatron]

It keeps getting overlooked that no one is saying they can't go in brackish. No one is arguing that they can't live in it long term and even breed very well. The only issue was whether or not it is better for them (and their kidneys and other internal organs) to be in fresh or brackish long term.

Exactly what I was thinking. Probably never gonna have mollies, but this is always a hot topic. That's why I wanted some sort of legit resource, I just want to know rather than hear "oh my fish are great!"

 

[Vircomore]

I've kept Mollies in freshwater (with some tonic salt every so often) for about a year now, and I also got a book about Livebearers that had a really great article about why Mollies are more often kept in pure freshwater aquariums.

The top 2 reasons they gave were:

1. The majority of Mollies sold in pet stores - with the exception of LFS that specifically sell brackish mollies - are Mollies that have been bred and raised in captivity in freshwater for several generations. This "freshwater farming" method tends to lower the Mollies' ability to acclimate to any marine salt.

2. Mollies are great community fish, but the options for a "brackish community" are extremely limited especially in tanks smaller than 30 gallons. Most people would rather forgo the salt in favor of being able to keep a wider variety of community fish.

 

[Scalare]

Most mollies sold today are bred and raised in freshwater, but they do seem prone to fungal diseases so I guess a little salt in the water would help prevent that, but salt in a community aquarium wouldn't really be a great idea, so fish in that situation would need to be kept in freshwater.

Pete

 

[Cobaltskyy]

sayin' you were using marine salt, right? i used aquarium salt for a long time before switching to marine salt. i know mine have become extreme breeding machines since i acclimatized them to low/mid salinity...i also keep pond/nuisance snails farming in the same tank for my green spotted puffer. a couple males are breeding/ agressive but not lethal by any means. the females can get away its a lightly planted tank with driftwood and bamboo, with aquaclear filter with pre-filter. Anyway pond snails and PLANTS can grow in brackish water as well... HARDNESS IS HIGH BUT PH IS 7.6 ISH SO I KEEP THE SALINITY UP

Yes absolutely marine salt... my ph was and is 6.8 au naturel. No additives just tap and de-chlorinators.....less is better in my experience, the more you mess with the chemistry in the tank the bigger chance for human error, deadly fluctuations, and wasted $.

 

[BillD]

The late Dr. Joanne Norton said salt was absolutely unnecessary for keeping mollies, however, clean water is. That is good enough for me.

 

[doogle]

ok.they can obviosly tolerate salt, quantity and exposure is debatable. with such a short life span -donthink internal damage is likely, not to mention theare found in brackish water. people who have expierince is way better than book smarts and theory, seen it on the job so much being a welder. anyway, these fish aRE VERY easily acclimatized to differing water conditions. many experienced mollie breeders will tell you adding salt is the most sensible aproach to helping these fish ''THRIVE'' in aquariums. if fish can THRIVE in aquariums...

 

[fishguy1]

Possibly, but you missed the point I was making there. They wouldn't occur and breed in those environments, if they had not evolved to be able to live there. I have never witnessed, or read of, any of these fish being in distress in a brackish tank. Just the opposite actually. They have always thrived in any brackish set-up I have seen them in. It may not be their primary habitat, but they still do well in it.

Evolving to be able to to tolerate conditions is not the same as an evolutionary step, as you are making it sound. Even what you said indicates that they are freshwater first. Many fish are able to live in environments outside their preferred range - the more prolific ones will even breed in them. Anabantiods have evolved to be able to live in low oxygen water - does that mean that's what we should provide our gouramis with?

I never claimed salt to be problematic for mollies, but the idea that they NEED it is one that often circulates unchecked.

Feral mollies have also managed to establish themselves in the marine Gulf of Thailand.

Just because you don't find them filling the waters like flies, it hardly means that they are struggling. Sparse can mean many things, such as not widespread, but concentrated in some areas.

We have a local striped bass population - they live here all year long. Once the migrating schools pass us on the way to virginia, striped bass become scarce, being concentrated in certain areas. Even though they stay local, they are still a migrating fish. You could say that they've evolved to not need to make the trek up and down the coast. Are they better off this way? They obviously think they are, or they would join the passing schools.

Being concentrated in an area only means that the conditions are favorable in THAT area. But you can't look at what goes on in those specific areas and apply that to the species as a whole. No matter how many stripers decide to spend the summer here at the jersey shore, they are STILL a migrating fish.

I may say that the flies sure seem to be rare anymore, when there is a new pig farm not 100 feet away. That doesn't mean that the flies are struggling, it just means that they aren't where I'm looking right now.

If they are SUPPOSED to be somewhere, and they aren't, then I would submit that they are struggling in that region. When the wolves were eradicated from yellowstone national park, it had an enormously bad effect of the environment. Foxes and coyotes were devastated, as they relied on the wolves kills to survive. Without the carcasses left behind by the wolves, they had to leave in order to find a place to live where they could support themselves. They were struggling, as were many other facets of the environment.

Once the wolves were reintroduced, a whole myriad of wild life returned to yellowstone, and the trees started to grow again (even the trees were struggling - dying off and not reproducing).

Sometimes when you are fishing, you don't see many fish. Does that mean the fish in it are struggling, or that I'm just in the wrong part of the lake?

90% of the fish are found in 10% of the water. It means you are struggling In a lake setting, there are all sorts of places that you would expect NOT to find the fish - there are many more places that DON'T hold fish than DO. If the fish population were thriving, you would find them in those places too. If the population were struggling, then you would have a hard time finding them, even in the areas that you would otherwise know them to be.

As for predation, that is NOT a weak point. Some mollies may have actually migrated to a brackish habitat to avoid predators. Just because mollies can adapt to saltwater, it does not follow that their predators can as well. New waters mean new challenges and different animals. That is one of the prime reasons animals move to new locations. To exploit new sources of food and to avoid predation.

Migrating to brackish water to escape freshwater predators only makes them targets for brackish water predators. There will ALWAYS be predators trying to eat them, no matter where they live. Predation is unavoidable, which is why I said it was a weak point.

 

[jenatron]

All I'm saying is I want something more than someone random on here saying their fish is doing great. I want it based on something real.
Where do you think all the information (like on Fishbase) comes from? Studies, research. That's first-hand experience.

 

[Shadowraven]

OK, just to make sure they everyone understands each other, I will post this reply.

Scientific Facts of which there can be no argument:

1) Mollies are freshwater fish that are found primarily in freshwater.
2) Mollies are found in hard, very alkaline water in nature.
3) While Mollies don't require salty conditions, they are quite capable of adapting easily to brackish or saltwater conditions as the need arises.
4) Mollies can be found in brackish water and marine water environments with stable, growing breeding populations.

You may have misunderstood what I was saying, but I never made any claims that are counter to any of the above statements.

What I was saying and what seems to have people divided here are...

The things that people seem to disagree about:

1) Mollies can not only adapt to brackish and marine environments, but they can thrive in them as well.
2) Since mollies come from hard, alkaline waters in nature, this makes it much easier for them to adapt to the very alkaline environments that exist in marine environments. The osmotic pressures they experience from both environments are very similar.

You're just splitting hairs on the metaphoric points above and I won't debate the issues on that basis.

jenatronQT3, I'm pretty good at searching for information on the net, but I still haven't found the actual research for you yet. That's hardly surprising though. Most of the time that information is in the scientific journals and they are not always easily available on the net. I'm still looking though and I'm confident that I'll find it sooner or later.

Until then here is a site that is a pretty good source of information for you. Follow this link for more information.

Edit: I take that back jenatronQT3, I have found something now. As is typical with scientific papers, the full paper is not available unless you are affiliated with the library or study. But the first page is available with an abstract of the conclusions of the full paper's contents. Follow this link to read it. It is about sailfin mollies, but should apply to both species as they are identical in most respects.

 

[McLumpy]

I have 4 Mollies, (3-Gold Dust and 1-Dalmation), in my community tank. Their tank mates consist of 1-Red Tail Shark, 1-Pleco, 1-Dwarf Gourami, 1-Swordtail, 2-Clown Loaches, and 8-Neon Tetras. I have been using API Freshwater Aquarium Salt for 7 months now w/ no adverse effects to any of my fish.

IME, I originally didn’t add salt when I first added my Mollies. Not only did they look unhealthy, but they were completely lethargic. I even lost a few due to causes unknown. But as soon as I started adding salt, their energy level and health immediately improved. All of my Gold Dust Mollies are the originals that I added after I finished cycling my tank. One fish in particular has, (what I believe to be), a birth defect. Yet, she’s healthy as can be, (minus her little wiggle and a recent fin rot issue), but I strongly feel that she would have been the first to die had it not been for me adding salt.

I keep the salinity level low too. During each weekly pwc, I add a total of 2 tablespoons of salt and let it dissolve completely before pouring the water in the tank. For a 55g tank, (and doing a 50% pwc), 2 tablespoons isn’t that much. Furthermore, I completely understand that some people choose to use salt as an Ich remedy and they believe that is the only reason anyone should add salt to a freshwater tank. However, since my fish have been raised in a somewhat brackish environment, I use Ich Attack to remedy my Ich outbreaks and it works well.

I believe that if salt works in your tank and for your fish… then use it.

 

[DragonFish71]

I keep our mollies at an SG of 1.015 and have for almost 3 years now. I do allow for tidal fluxes, which are found in nature. One cleaning a month I do not add reef salt.

The only deaths we have had were from when we took the tank down in November to put in hard wood floors. We still have our original mollies and some grown fry from when we started the tank. We have had no problems with velvet, of which mollies are notoriously susceptible to, no ich, no anything. Well, other than the mollies and ghost shrimp ganging up on one of our dragon gobys and pushing him out of the tank. Yeah, I still think they committed murder.

Personally, I'd rather put stock in what I've seen and experienced than some person who claims prestige or people who only experiment for a month or two. Long term is the key and I'm thinking almost 3 years with healthy mollies sums it up for me.

 

[Shadowraven]

I agree with both of you. I can give you the facts, but experience is the better teacher. All I can tell you is that I have never heard of, or seen a case where, salt has done any harm to mollies (or swords or platies) in any way.

I have heard before what you two have just said here. That the addition of salt to the tank actually helped them. I am more inclined to believe that it had more to do with the increased alkalinity of the water, but I'm for whatever works. Mollies like very alkaline water (7.5-8.0 pH) and will always do better in it. In any case, the addition of salt to the tank doesn't hurt them.

 

[Fishguy2727]

Great find on that article.

It is hard to find truly scientific data on aquarium fish for a few reasons. For one most research is done on species that are more economically valuable (food fish). If species found in aquariums are used the study usually has nothing to do with anything that aquarists can benefit from (functions of certain enzymes, receptor blocking, etc.). Primary research articles, peer-reviewed articles published in scientific journals, are not available to the general public. As stated you may get the first page, abstract, and maybe the references, but the actual article is not available for free. It is only available to people who subscribe to the journal (doctors, researchers, universities, etc.). I had access to these articles through the university when I was getting my degree (how I got info on garlic, goldfish, and a few other things). But now I am stuck with Google scholar searches and an abstract.

Popular articles (yahoo, the news, etc.) are all non-scientific sources that may report on a primary research article. These sources are very dangerous though. After reading through enough primary research articles I can say that some experiments are not very good, or do not really support the conclusion the scientist claims. Take it a step further and let journalists who do not have a background in any type of science take an article and present it to the public and you are lucky to get the basic idea across.

In this hobby we need to take advantage of the scientific information that is available, but when it is not we must look to each other. Not a single one of us has the key or an invaluable, unquestionable experience. But together we have data that can be invaluable to other aquarists. We have the key to advancing the hobby as a whole.

Again, keep in mind that whether or not mollies will truly do their best in fresh or brackish only matters if they are the only species in the tank or you are considering adding them to a brackish tank. If any freshwater species is present no salt should be added.

It was said earlier that their lifespans are so short that we cannot cause kidney damage. This is absolutely not true. Permanent damage to internal organs can happen. Depending on the exposure time, dose, etc. damage can occur in years, months, or even weeks. Most likely it is the internal harm that we unknowingly cause that kills effectively all of our fish. They do not die of old age. They die of care problems. Low water quality for years, a diet deficient in certain nutrients (even just trace elements), etc. cause damage. It is this damage that likely causes most of the long term problems in our fish.

 

[McLumpy]

Again, keep in mind that whether or not mollies will truly do their best in fresh or brackish only matters if they are the only species in the tank or you are considering adding them to a brackish tank. If any freshwater species is present no salt should be added.

Is this statement based on your opinion or is this a fact or an opinion of an ichthyologist? I ask because there seems to be a lot of discussion on this thread about fact vs opinion vs actual experience.

Just wondering.

 

[Fishguy2727]

There is a lot of evidence out their (contrary to P**smart's belief) that adding salt all of the time is harmful to freshwater fish. It does cause damage and long term problems. There are usually only two people wanting you to add salt, the store selling it and the company making it. To make it worse the recommended dosing is ridiculous. It is usually recommended to add one tablespoon per five gallons. If you supplement special salt for cichlids from Lake Tanganyika (the hardest, most alkaline body of freshwater on the planet) the dose is half a tablespoon per ten gallons. They actually recommend you dose all freshwater fish with 4x what is needed for Lake Tanganyika! That alone should shoot up a red flag to every aquarist out there. Even if you think it is good to always add salt you should realize that the recommended dose doesn't make sense.

It is also commonly repeated that scaleless fish can't tolerate salt and then the examples given include plecos and cories. Scalation doesn't effect tolerance to salt. Salt gets into the body through the gills, just like meds. If scalation did effect tolerance to salt then cories and plecos should be more tolerant of it becuase of their increased scalation. This idea also demonstrates that at least parts of the 'salt for all' idea is not correct.

The long term constant use of salt in freshwater aquariums has unseen (internal) major damage and effectively cuts years off your fish's life. It is an amazing short term, non-medication treatment that can be very effective. I used it all the time in the shop I was running. But using it all the time is not something I would do or recommend, as an aquarist or as a Biologist.

I am sorry that I do not have any scientific articles on hand to support this. This discussion may make me take a good long look for/at some to see what is out there (if I get time between being here, work, running my business, etc.).