07-04-2011, 05:24 PM
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Originally Posted by amazon21
I've done a little research about it, and from what I've heard, it seems that tank raised cardinals adapt better to hard water than wild caught ones. Of course, I havn't found any studies or experts explaining this topic, just other fish profiles in other sites and forum posts. If it is true that tank raised cardinals adapt better to hard water, I would guess it is because tank raised Cardinals come to the pet store young, which makes it easier for them to adapt to hard water while the wild caught Cardinals which are adults. Your explanation makes a lot of sense as well. I wasn't sure if "adapt" also referred to the calcium problem, but as you said nature probably can't be side-stepped like that, so I'm guessing a tank-raised cardinal would have a short lifespan in hard water just like a wild caught cardinal tetra.
The age of the fish is a valid point but I think may not apply nonetheless. Most wild caught fish are very young, the prime collection time is a couple months post hatching and this is largely regulated by law now to ensure the wild stock is not exterminated by over-collection and to protect the spawning period. In my local store that regularly has both wild and tank-raised cardinals, they are exactly the same size, about 1/2 to 3/4 of an inch.
Do you have links to those sites where it suggests tank raised cardinals can adapt to harder water? I'd like to pursue this. I frankly find it less than believable. Adaptation in such fish means the fish's physiology is somehow being altered to manage in different parameters. And while this is certainly possible--after all, evolution is just this very thing, all species on earth have evolved to suit their present environment, and the cardinals have evolved over millions of years to require very soft acidic water--achieving this by raising them in a tank of soft water does not seem probable. It would presumably require several generations of increasingly harder water, and the fish would either evolve or die out. If you can provide these links, I would be interested, and might even pose the question to someone like Dr. Stanley Weitzman.