Sick Siren? Please help

[Sperlerpinae]

I got a Greater Siren two weeks ago and I have it in a 20L tank on gravel with a filter. The siren is about 18 inches. It took a few days before it would take the blood worms cubes, but then it was eating pretty ravenously. I've noticed the siren comes to the top of tank quite often for air so I added an air stone recently. Last night I noticed the siren seemed to be distressed...kind of thrashing around and gill flushing. I emptied out some of the water today because she seemed like she was struggling to get to the surface. Now that I've lowered the water level she seems more comfortable, but I'm still worried.

Anyone have any ideas or suggestions?

 

[Jennewt]

Two weeks is just about the time that a new tank will develop ammonia - I'd recommend testing for it. Also, the combination of bloodworms + gravel is a prescription for ammonia. A few stray bloodworms decaying in the gravel can turn the water quality sour very quickly. I'd recommend doing a 50% water change daily if there is any question of water quality problems. Don't clean the whole tank out, though.

What is the water temperature?

By "20L" I assume you mean 20-long, not 20-liter? Even so, that's going to be kind of small for a full grown greater siren.

 

[Infamous82]

Probably a water quality issue. My siren tended to like 6 in or less of water depth and plenty of cover. I would definitely change the substrate and make sure it has a hide and maybe some fake plants. They feed readily on earthworms as well