Help! -gymnothorax Tile-

[SMAUG]

This afternoon, i found my snowflake eel rolling around on his back, gulping (breathing) heavily.
He would otherwise lie motionless for several minutes, then go into a frenzy of twisting and twirling at midwater.
i assumed the water was the problem and imediatly moved him to the 50g freshwater tank.

The eel is very small about 20 cm in length. and so for now, i have been keeping him in a 20 gallon brackish tank.
previously, the SG was at 1.006, today i did a water change and lifted the SG to 1.008.
All water parameters are otherwise fine.
i change 25% of the water every 3 days, as i know he puts a large bio load on the small aqauarium.
up until today he has been eating regularily. 1 peice of prawn each night.
He has grown about 5 cm in 2 months and so i believe up until now he has been healthy. (and active)

I know these can be problem fish and i imagine, lots of other people have had some sort of similar scenario.
can anybody please help. the little guy has been really sweet so far.

personal opinion is that i lifted the salt content too quickly.
i had a pair of guppy fry in there as advance warning, but they appear to be fine. i guess that they're more hardy.
thankyou in advance

-Tom

 

[andywg]

It is very hard to lift the salinity too quickly for truly euryhaline fish such as G. tile. However, it is possible to lift it too quickly for the filter bacteria, thus causing ammonia and nitrite spikes which the eel will not appreciate.

Check the brackish tank's ammonia and nitrite levels to see if that is the problem. Other than that, the only problem I am aware of is an apparent urge to spawn when the weather gets too hot (as observed by CFC on more than one occasion).

 

[SMAUG]

Thank you very much for the answer.
the eel seems to be recovering well in the tropical tank.

In my panic i was not thinking straight.
i had read about allowing the filter bacteria to acclimatise.

i had raised the SG slowly i thought, but it seems this could take many months.
lesson learnt!
thanks again.