Zebra Danios

[Pablos]

I have a Zebra Danio in the bottom corner of my tank swimming in circles with his tail on the gravel
What does this mean?
Sorry if its a stupid question but i aint seen this before

 

[Tokis-Phoenix]

Sounds like a swim bladder disorder, this can be brought on by infection and/or environmental conditions. Finding the cause of the illness is the best way to treat it, so we will need to know more about your situation;
a. How many gallons is the tank and how long has it been set up?
b. Have you any recent test results/stats for ammonia, nitrites and nitrates?
c. What sorts of fish do you have and how many plus any other inhabitants in the tank?
d. How do you go about keeping up hygene levels in the tank and how often (like water changes, cleaning substrate and filter sponge etc)?
e. What sorts of foods do you feed the fish and how often/much on average roughly ?

 

[Irf]

Hmmm - I've lost four zebra danios in this way over the past two months. Each one was a bit different, but they got progressively weaker and a couple of them got an ulcer on their bodies.

Never really found out why....

Hope you get it sorted out!

Irf.