What kind of arowana is this?

[Hao]

I am not sue that RTGs, even HBs can be blue base.

All gold aros (both XB and HBRTG/RTG) will show some degree of blue depending on the angle (usually will see more from a lower angle) and how the light hits the scales. Genetics definitely do play a role in how much blue one expresses too.
As for whether or not this is an “HBRTG” or “lower shine XB” is kind of up for debate (unless they have a certificate from the actual farm). People will have different opinions on this too. Just my 2 cents but if the gold aro has pearlies, I’d consider it an XB. This one has some, and probably will develop more and a higher shine as it grows (assuming they raise it well).
I’ve seen people share their “SHBRTG” and it has 6th level shine (not fully crossed) and full pearlies. Personally I’d just call it an XB especially since it clearly predominantly has XB genes (reminder HBRTG are XB x RTG).

 

[stratos]

I am not sue that RTGs, even HBs can be blue base.

Oh yes, it's quite common now, especially for HBRTG's. The "true" RTG's from Indonesia are not blue base.

 

[stratos]

All gold aros (both XB and HBRTG/RTG) will show some degree of blue depending on the angle (usually will see more from a lower angle) and how the light hits the scales. Genetics definitely do play a role in how much blue one expresses too.
As for whether or not this is an “HBRTG” or “lower shine XB” is kind of up for debate (unless they have a certificate from the actual farm). People will have different opinions on this too. Just my 2 cents but if the gold aro has pearlies, I’d consider it an XB. This one has some, and probably will develop more and a higher shine as it grows (assuming they raise it well).
I’ve seen people share their “SHBRTG” and it has 6th level shine (not fully crossed) and full pearlies. Personally I’d just call it an XB especially since it clearly predominantly has XB genes (reminder HBRTG are XB x RTG).

And then there are the XB/HB's that are offered by some farms, which in my opinion are really just XB's. And then to complicate matters even further, there are the farms that sell surplus full blood XB's as HBRTG's at a discounted price; the reason for this is they have an oversupply of XB's, but don't want to undercut their own XB pricing by having a "sale" and so just call them HBRTG's when in fact they are XB's. It's confusing at times for sure. I am personally a huge fan of the Merlion Dreamfish farm; their Taiwanese subsidiary page shows some nice bloodlines they have: https://www.facebook.com/profile.php?id=100057497409238