Juvenile cryptarius truncatus unusual behaviour

[tongolino10]

I managed to acquire two cryptarius truncatus juveniles around 2.5cm in length and they are very hearty eaters of frozen bloodworms.

At the aquarium where I purchased them, I noticed that their standard posture is to float at the surface. When I enquired more about their behaviour, I was told that they have exhibited this behaviour ever since they arrived a few weeks ago.

Due to their very small size, both the aquarium and myself keep them in a breeding box affixed inside a larger tank. Water quality in my tank is tested weekly and ammonia and nitrate levels are typically low. Oxygen levels are also not an issue. Water is also changed weekly.

I do not notice any sores or unusual bluges in the catfish bodies, and they are able to swim downwards at will to pick off any bloodworms I feed them

This does make me wonder if its anything to do with their swim bladder, or if there are any other issues that cause this behaviour. I'm hoping its just a behavioural quirk of cryptarius.

Would anyone have an idea of what may be causing this? Are there also other keepers of cryptarius here?

 

[tlindsey]

I managed to acquire two cryptarius truncatus juveniles around 2.5cm in length and they are very hearty eaters of frozen bloodworms.

At the aquarium where I purchased them, I noticed that their standard posture is to float at the surface. When I enquired more about their behaviour, I was told that they have exhibited this behaviour ever since they arrived a few weeks ago.

Due to their very small size, both the aquarium and myself keep them in a breeding box affixed inside a larger tank. Water quality in my tank is tested weekly and ammonia and nitrate levels are typically low. Oxygen levels are also not an issue. Water is also changed weekly.

I do not notice any sores or unusual bluges in the catfish bodies, and they are able to swim downwards at will to pick off any bloodworms I feed them

This does make me wonder if its anything to do with their swim bladder, or if there are any other issues that cause this behaviour. I'm hoping its just a behavioural quirk of cryptarius.

Would anyone have an idea of what may be causing this? Are there also other keepers of cryptarius here?

Fishman Dave

 

[thebiggerthebetter]

Never heard of this particular species before. It seems odd for them to be at the surface but maybe they simply don't like the feeling of the bottom of the breeder box on their stomach or something else. It's not natural for a fish to sit in a fabric box in a larger vessel of water, which coincides with this unnatural choice of position, perhaps for a reason, perhaps a mere coincidence.

Once you release them into the tank and this continues, then I'd be a bit more worried. The fact that they feed now says they can't be too uncomfortable.

 

[Fishman Dave]

Not a fish o have ever come across but would be eager to acquire if I did.
I do wonder if it’s one of those fish that even at a younger age prefers brackish waters.

 

[tongolino10]

just thought I'd update on what I noticed at another aquarium which also stocks juveniles. it appears that they too exhibit similar behaviour at the surface, however they don't seem to float as much due to the presence of a strong surface current from a powerhead.

at the first aquarium they were kept in somewhat light brackish conditions, though the exact salinity was not tested. it was at a level that was sufficient for gymnothorax tile adults to seemingly thrive in though, so I'm not sure if salinity levels have to do with the behaviour