I'm glad you're happy with it, it's all to often that people buy one in the hope that it's a Xingu (or any of the others) and it's the 'normal' Panaque nigrolineatus/L190.
The easiest way to tell a Tocantins apart from a Xingu is that they are pretty much brown, and also seem to be a slimmer fish. At least up until about 17cm, I only have the one at this size and very rarely see pictures of adults.
The Tocantins is in the middle upside down, the rest are Xingu.
Xingu VS P. nigro
