I've seen one, and too be truefull it scared the s*** out of me, i was told to stamp me foot, so i did, and within seconds, it was up close to the glass, and waiting, it was mean, and nothing I would ever have.
He told me that after this one dies it will be his last, as there very unpredictable, in the fact that it will run towards you a soon as you open the tank to feed it, so you have to be very quick.
There very Fast (he said: they can out run a human), very aggressive, can run up glass quicker then my pokie, and have a very painfull bite, and the set ups for them need to be huge, 4 foot fish tank is min. I read that they only live for 1-5 months in captivity as in the wild there hunting ground is anywhere, so I've read that the set ups for them have to be big, in order to get them to live longer.
I very much doubt your'll find many that will keep this animal, and the ones that do, will only know the basics, because of the lack of knowledge in the speices.
good luck thou,