Gymnothorax polyuranodon

[BlueLineAquaticsSC]

So I was perusing Aquabid and saw a Gymnothorax polyuranodon, aka Tiger Moray Eel, and, completely by accident, I somehow bought it. Funny how those things happen. Anyway, anyone ever keep one before and have any advice, besides a bullet proof air tight lid.

[RennjiDK]

I don't believe that you accidentally bought a $200, 24" long predator with a 120g specialized tank requirement. Having said that, aside from the the lack of salinity, care and husbandry seems to be about the same as their SW equivalents. There's plenty of guides and videos on moray care. You should brush up on them before it arrives if you can't cancel the transaction.

The only real advice I can give you is based off of my limited knowledge of their SW counterparts. Tropic tempatures, with plenty of hiding places. You'll need to feed several times a day with large pieces of raw jumbo shrimp and seafood as a juvenile,  and once per week as an adult. USE CORAL TONGS WHICH KEEP YOUR HANDS FREE OF THE TANK. A bite can result in stitches or infection at best, or instant amputation at worst.

Edited May 27, 2023 by RennjiDK

[BlueLineAquaticsSC]

Accidentally is how I describe it to my wife of course. I do have an empty 90g that’s been cycling and ready for it when it arrives and I have done some research before hand. I’m mostly wondering about tank mates. Most things I’ve read says they are fairly docile and won’t attack anything to big to be food, but everything I know about Morays makes me hesitant to believe that this guy could co-hab well with most things.

[Biotope Biologist]

Large fast moving brackish fish tend to do well as tankmates. Moray are nocturnal hunters but know what they can and cannot eat.

 

Scat, Monos, Archer fish are its usual tank cohabitants. There are some stories of “freshwater damsel fish” doing  well. Bit of a misnomer they are not freshwater but brackish water fish. But damsels can be kinda bullies sometimes even to fish much larger than them. 
 

You could also do a school of mollies knowing full well that they will get picked off, but they breed fast enough to maintain the population 

[BlueLineAquaticsSC]

On 5/27/2023 at 11:32 AM, Biotope Biologist said:

Large fast moving brackish fish tend to do well as tankmates. Moray are nocturnal hunters but know what they can and cannot eat.

 

Scat, Monos, Archer fish are its usual tank cohabitants. There are some stories of “freshwater damsel fish” doing  well. Bit of a misnomer they are not freshwater but brackish water fish. But damsels can be kinda bullies sometimes even to fish much larger than them. 
 

You could also do a school of mollies knowing full well that they will get picked off, but they breed fast enough to maintain the population 

Archers sound really cool. From what I’ve researched this specific species is the only true fresh water Moray, so I’m going to try keeping it fresh first and then going brackish if it doesn’t like that long term.

[Biotope Biologist]

There is no such a thing as a freshwater moray. There are freshwater eels but morays are not one of them. 
 

They can live long term in freshwater. Up to 5 years. But in the aquaria gymnothorax do best with at least some salt. A minimum I would say of 1.008.

 

In the wild they travel to freshwater streams and river inlets to spawn. But evidence suggests that they only tolerate freshwater. 

[RennjiDK]

On 5/27/2023 at 1:09 PM, Biotope Biologist said:

There is no such a thing as a freshwater moray. There are freshwater eels but morays are not one of them. 
 

They can live long term in freshwater. Up to 5 years. But in the aquaria gymnothorax do best with at least some salt. A minimum I would say of 1.008.

 

In the wild they travel to freshwater streams and river inlets to spawn. But evidence suggests that they only tolerate freshwater. 

If you're going to run brackish, there are salt mixes that do not have the added Cal, Alk, and trace supplements needed for coral. I believe Brightwell makes one.

[BlueLineAquaticsSC]

On 5/27/2023 at 1:09 PM, Biotope Biologist said:

There is no such a thing as a freshwater moray. There are freshwater eels but morays are not one of them. 
 

They can live long term in freshwater. Up to 5 years. But in the aquaria gymnothorax do best with at least some salt. A minimum I would say of 1.008.

 

In the wild they travel to freshwater streams and river inlets to spawn. But evidence suggests that they only tolerate freshwater. 

Every sight I’ve see. States that Gymnothorax Polyuranadon is the only moray that can go fresh its whole life, it just won’t spawn without brackish/marine conditions. I do want to try running the tank fresh, but just in case what are some warning signs I should look for showing it needs to be moved to brackish?

[Biotope Biologist]

Not it’s whole life and again many gymnothorax species can tolerate freshwater. Some say indefinitely, but looking at their natural history they are most typically found from adolescent to adulthood in mangrove forests. The range of salinity here wildly fluctuates. 
 

Morays will not show signs of stress. If you would like you can incrementally increase the salt in the tank. 1.008 is very low end brackish. 1.015-1.024 is mid to low end marine. I would not go past 1.018 personally. 
 

This is not my tank do with it as you wish, but you will see better success in low end brackish with some salt. The beauty of brackish is that it’s not an exact science. It’s an inbetween. It’s very unpopular so there is not a ton of info or fish species in the trade for it. 

[BlueLineAquaticsSC]

@Biotope Biologist hmm, well this does have me thinking brackish is the better choice, and TBH I’ve always wanted to do a brackish set up, maybe I’ll through in a trio of green spot puffers. Slowly increasing to brackish doesn’t seem so bad since I won’t have to worry about it right away.