It looks like the wunderpus was first discovered in the mid-1980s and occasionally in captivity from that time onwards. The species was only formally described in 2006. http://www.mapress.com/mr/content/v26/2006f/n3p140.pdf
In the originaly discription it even is mentioned that one of the specimens used for the discription was obtained from commercial fish-collectors !
Even so, it is realy rare in captivity and sofar, I've never seen it !