Neon Tetra Fat Belly

[Fishmanic]

One of my 8 neon tetras has an enlarged belly.  I believe he's eating, but he's not swimming as fast as he used to.  What could be the cause of this?

 

[Arcticfox1977]

A picture would be helpful. Failing that it could be a female ready to lay eggs.

 

[Ch4rlie]

A pic of the bloated tetra may help.
 
Also, can you specify what you feed your fish and how often.
 
First thing comes to mind is overfeeding perhaps. Might be an idea not to feed your stocking for a day or two to see if this makes any difference.
 
If not, then possibly could be constipation, you may want to try feeding peas to see if this helps.
 
Or as Articfox suggestes, could be a pregnant female, though I am not sure how to tell genders in neon tetras, think the strip along the sides are slightly different as far as i know, hopefully someone can chime in with a good way to tell genders in neon tetras.

 

[Gvilleguy]

Most likely would be eggs...

 

[the_lock_man]

One of my 8 neon tetras has an enlarged belly.  I believe he's eating, but he's not swimming as fast as he used to.  What could be the cause of this?

 
It could be a lot of things - it could be a gravid female, it could be bloated, it could be an internal parasitic infection, it could be a tumour, etc, etc.
 

Most likely would be eggs...

 
Without seeing a photo of the fish, I think it's impossible to say which of the various possible causes is any more likely than any others.