"Freshwater" Tiger Moray eel Gymnothorax polyuranodon

shev

Feeder Fish
May 6, 2014
4
5
0
Ca
Hello everyone, new to the forum, and certainly new to these fish. Anyone have experience? I'm looking for a an interesting fish for a planted aquarium, one that will hide in a tube the majority of the time. There's a seller that has these listed as:

"found in true freshwater to slightly brackish environments. Growth rates and coloration seem to improve with the addition of marine salt to less <5%. 81% of the collection records are from 100% freshwater with the remaining collections in estuaries with less than 5% salinity."

But after some quick google searches, most people are saying they are only temporarily freshwater, and ultimately need a decent amount of salinity. Also, after watching some youtube videos of "freshwater" moray eels, all of their colors are very faded, and pathetic looking in general. I'm assuming these are being kept in entirely freshwater aquariums. So, does anyone have any experience with these? What salinity do you keep them in? What size tank?

A picture from their website:


^ that coloring is absolutely gorgeous. I have not seen anything close to that in FW aquariums.
 

shev

Feeder Fish
May 6, 2014
4
5
0
Ca
Well that is what I'm looking to hear. There does seem to be some debate on the topic. I found this:

"Analysis of 36 records of the rarely encountered moray Gymnothorax polyuranodon indicate that juveniles and adults inhabit fresh and mildly brackish habitats (salinity < 5) in streams of the Australian Wet Tropics Eighty-one per cent of these records were from freshwater streams and collectively demonstrate that this species inhabits fresh water throughout all seasons. A survey of fish researchers, each with at least 100 h of field experience in Australia's Wet Tropics, revealed that 33% of researchers working in fresh waters (nine of 27 researchers) had encountered the species and 15% of researchers with substantial experience working in estuaries (two of 13 researchers) had encountered the species. The species was not sampled or observed in the nearshore marine environment. The only record of an elver of this species was, however, found in an estuary at a salinity of 33·4. This preliminary evidence suggests adult G. polyuranodon occupy freshwater habitats, but further research is required to understand the complete life cycle, including movements, habitat use and reproductive ecology of the species."


I might just get one, and if his colors start to fade, I'll up the salt gradually until his colors come back. And then I'll see what plants can handle the added salt.
 

Aw3s0m3

Piranha
MFK Member
May 6, 2012
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I'd say go for it. There's another thread on here, sorry I don't remember the title, but a member caught a bunch of all sizes including some pretty big ones in pure fw. I've also never seen this eel for sale in pure sw and I've kept my fair share of sw morays.


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DB junkie

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Jan 27, 2007
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These eels aren't something I'd consider "common". The common FW Morays are Gymnothorax Tile, these are drab colored in fresh or the salt they need as adults.

I've never heard of Polyuranadon loosing color in freshwater. The owner of this site had some for several years in freshwater, but not sure if he still has them or not, but I know several of us have them in freshwater and plan to keep them there..... I've had mine with Vitatus ATF for several months and plan to keep them together.
 
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shev

Feeder Fish
May 6, 2014
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Ca
I didn't consider that they lose their color with age regardless of what water they're in.

I might just go with some rarer type of spiny eel.
 
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masone

Candiru
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Feb 5, 2006
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Not sure why you think they fade with age, have a few large ones that have better colours than some of my smaller ones, including one that is going to a red base.
 

FearsomeFish24

Feeder Fish
Jun 7, 2017
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These eels aren't something I'd consider "common". The common FW Morays are Gymnothorax Tile, these are drab colored in fresh or the salt they need as adults.

I've never heard of Polyuranadon loosing color in freshwater. The owner of this site had some for several years in freshwater, but not sure if he still has them or not, but I know several of us have them in freshwater and plan to keep them there..... I've had mine with Vitatus ATF for several months and plan to keep them together.

How small have you had them? I found a small one for sale and I want to get feeding tips before I get him.
 

Experiment397

Redtail Catfish
MFK Member
Feb 26, 2010
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Probably the Poly section
Ive seen a few of these before in full fw tanks and they all seemed healthy and vibrant. Ive heard they were super shy eaters though and didn't do well with tankmates that were more voracious and active eaters
 
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