Strange behaviour by fish

[GillesF]

Hello

I have in my tank about 10 Rasbora Heteromorpha. I just fed them and when they went to the surface to eat it looked like they were knocked down. So now I have like 6 fish on their side/ floating in the tank (still living). I've seen this before with one of them and he always survived. What causes this strange behaviour?

I know this sounds funny and strange but I'm not making this up lol

Could it be the high CO2 in the tank and high O2 outside? So when they eat they suddenly inhale lot's of O2?

Best,
Gilles

 

[Ady34]

Hi there,
i noticed this same behaviour with my harlequins a while back.
It was during a phase of trying to optimise c02 which i had just increased, i therefore drew a conclusion of c02 overdose.... perhaps wrongly?
Ill be interested to see other replies.
Ady.

 

[GillesF]

Anyone?

 

[awtong]

Is it possible they rose too quickly in the water going for the food and gave themselves the bends?

Once they drop back down the gas re-dissolves in the blood and they recover.

I have no experience of this and I am making a bit of a leap but it is possible for fish to get the bends.

Andy

 

[KittyKat]

What foods are you feeding them? Does it always happen with the same food or with different foods?

Since I have little experience with CO2, I cannot comment on it from that point of view.

Is it possible they rose too quickly in the water going for the food and gave themselves the bends?

Unless CO2 does have some effect on this, it is extremely unlikely. I suspect that the fish would need to be coming up fast from a depth of more than a few meters for this to be an issue.

 

[Mortis]

Maybe they breathed in a few undissolved CO2 bubbles that were floating on the surface ?