Mono's in FW??

Dangerdoll

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Aug 27, 2002
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I went to the lfs today and was a bit surprised at what I saw today. I saw 2 tanks full of Mono's in FW with plants, gravel, and other micellaneous FW fishes....the works. I mentioned to the worker that I thought Mono's were strictly a BW fish and he said, they do better in BW but will do alright in FW. I wasn't buying it. I absolutely love the mono's but don't have a BW tank, and as much as I do like them, I couldn't bring myself to put them through FW living......I would figure BW would be optimum for them, but would they REALLY survive well enough in FW?
 
I could be wrong, but don't they need full-strength marine water as they age? If so, I don't think that FW is the way to go, and I think that, if you were to buy those fish, you would need to slowly acclimate them to BW conditions.
 
yeah, he also said they can even survive in full marine.....I didn't believe it was right and this is why I was having a hard time with his answer.
ok, just so I understand then, with these guys, they would be like those shark catfish that can start off in FW but must be acclimated and finally placed in BW in order to live optimally, right? Is there a certain size they get to when it becomes that time to start acclimating? (hope I'm not making this too complicated, just was always intrigued by the Mon's, they're beauties X2.)
 
Monos will will do fine in freshwater while still very young and small, but as they mature they will need increasingly more salt until the level reaches that in marine water. Monos live primarly in marine water, they will move into fresh water to spawn. I don't know the size or age that they need to be brought into brackish water, but the research I did suggests that it should start when very young.
 
We have a store down in Denver that has Mono Sebaes in FW! Poor things! These are full (as full as they are going to get in FW) grown adults which is about 6 inches top to bottom! The way Monos work like goldfish freak said was they are a true Saltwater fish but migrate to FW to breed then migrate back to saltwater. The young go uncared for in freshwater then slowly start making their way to brackish and as adults finally migrate out to saltwater. Monos CAN live in freshwater with a high enough pH (7.6+) but why make them suffer in fw when they would be SO much happier in BW then SW. Hope this helps, and hope someday you can get a BW/SW tank for these wonderful fish!
 
If monos prefer FW to spawn, why are your spawning in SW?
 
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