Cross belly XB


Arowana blogger
See attached photo of a cross belly. A longtime forum member emailed me about these guys, wondering how they are made to look the way they do.

I passed the questions on to Nic of Dreamfish. What follows is a record of our discussion, released with his consent:

Me: Have you seen this fish before? What is it?

Nic: Cross belly XB

Me: Subject to special lighting?

Nic: Its mutant

Me: Interesting

Nic: I use to cross blue base to create chocolate blue. Somehow it (cross belly XB) is getting more common due to hormone feeding and colour enhancer feed.

Me: I have a customer asking me about this

Nic: Its difficult...most exhibit when semi-adult. When young look like any normal XB.

Me: Interesting. So not line bred?

Nic: I'm trying to

Me: Sounds a bit like GH in early days

Nic: GH is not about bloodline...but tanning technique

Me: I thought it started with some genetic mutation? One of the founder of Pang Long told me about how it was initially mutation that then led to line breeding with domination of WTT and lighting. Is that right?

Nic: Some breeder tried but I didn't see any success getting it right for line breeding. Some cross belly are not pure XB. Most cross belly are found in authentic RTG

Me: Interesting stuff for old hobbyist like me :) And others no doubt :)

Nic: Yes. Getting the brooders is not easy. And expensive.

Here is a video of a cross belly:

And another link:


  • Crossbelly.jpg
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Super Moderator
Interesting so maybe someday we will see more of these..So would this arowana look the same under normal lighting with sand substrate and a painted black background on the tank?