<a href=showthread.php?s=&postid=7772263#post7772263 target=_blank>Originally posted</a> by phender
When you say "normal rbtas" I assume you are refering to the relatively cheap rbtas that flooded the market a few years back.
IME, the difference is the cheap ones tend to be greenish at the base of their tentalces and sometimes on the oral disk. The old style rbtas whether they come from Tonga, Fiji, Indonesia or wherever, tend to be a more deep rose(maroon) color and don't have any hint on green in them at all.