Flounder

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black_sun

Fire Eel
MFK Member
Jul 31, 2008
1,136
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New Jersey
A while back I saw a fish called a "freshwater flounder" on an online store and thought it looked really awesome. I did a little research and found out that that generic name and only one of many ("flounder" "freshwater flounder" "tonguefish" "sole" etc), and that each site seemed to come with different care descriptions (despite the fact that they seemed to be all using the same series of photographs) in terms of tank requirements, feeding, size, etc. Most seemed to agree that it was a brackish water fish, though they were plenty that said freshwater and saltwater.

Anyway, I forgot about the fish until I saw it again at a LFS a few days ago in a saltwater tank and I became interested in it again. So, instead of going on another confusing info hunt I was hoping someone here kept this fish and could give me advice and personal experience in regards to keeping it.

Like how big does it get and how quickly does it grow?
Is it really a brackish water fish, or is it freshwater, saltwater, able to live in all three?
How big of a tank does it require, as a permanent tank?
Is it a long lived fish?
Is it difficult or easy to have in an aquarium?
Etc

Thanks!
 
FW is working for me. I found nothing that says they require salt.

Apparently to about 8".
Needs a sand bed or bare bottom.
Doesn't like bright light. Stays in the shadows, or comes out at night.

Eats pretty much anything I put in.
 
They do need sand. Another issue with these is that they do need target feeding in order to get the food to them. I've always found them to be hard to feed. If you're in the U.S. they most likely are some kind of hogchoker, so I assume they would prefer brackish conditions.
 
Will Hayward;2185308; said:
If you use foods that reach the bottom, and the other fish in the tank don't gobble it all up before it sinks, then they eat well enough. Could help to feed once the lights are off.

this depends what kind of tankmates they have. Personally, I used to use a syringe to squirt the frozen food (bloodworms or brine shrimp) down to where the flounder is. I've thought that in the future maybe stocking flounders with a pure topwater fish, maybe halfbeaks
 
Every fish store I have worked at (many) these things drop constantly.
I am assuming they ship rather poorly, at least from previous distributors I have dealt with.
Sand bottom by far.
VERY VERY uninterested and well-fed tankmates. These flounder are like the ultimate punching bag. Also, tankmates that will allow them some food.
I hear size 6-8".
I think water params might depend on size. A couple people on this site have large ones that are housed totally in fresh and are thriving.
 
There is a method of finding out what water conditions they need, although this isn't the best of methods and I wouldn't use it without doing some reading before hand.

Most of the true freshwater flounder species that come into shops are from South America and Australia, although SA has a few brackish species too. The most common true freshwater flounder is Brachirus salinarum, and Australian species.

Then there is the North American species - Trinectes maculates - the Hogchoker. This species appreciates salt anywhere from brackish to marine conditions. While indeed it is found in freshwater, for long term health please keep it in somewhat salty water.
 
SalmonAfrica;2266454; said:
Then there is the North American species - Trinectes maculates - the Hogchoker. This species appreciates salt anywhere from brackish to marine conditions. While indeed it is found in freshwater, for long term health please keep it in somewhat salty water.

It is probably a 95% chance that this species is the one encountered at the LFS, so I would treat it as such and keep with some salt as SalmonAfrica mentioned.
 
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