hi, i have 2 piranhas, there bout 3/4 years old now, they had really bright red bellies full of colour,, but just recently the are really black and dull bin like it for a few weeks, they are also doing what looks like whispering and dancing with each, was just wondering if thats normal or if something is going on,

thanks russ

Hi Russ to Piranha Forum. It sounds like your fish may be going through a spawning ritual. Its common for them to go very dark and shimmy alongside each other, if they are. The male digs a shallow pit and mouths the gravel a lot. If they do spawn they will swim over the pit and hover together, the female releasing eggs as the male fertilizes them. The eggs are a light orange in colour and its the male that tends them until they are free swimming.
Let us know how it goes, do you have any pictures?

Sounds like you got a horny couple.
It could very well be pre-spawning behavior, check for blowing holes in the gravel. That would indicate building a nesting place

thanks guys, one as bin mouthing the gravel too, i thought something was wrong with the tank but now u mentioned that it seemed so simple, thanks for the insight,

no i dont have any pictures but i will get some soon,

Just read the breeding forums, will help you understand what's going on I think.