Here you go:
Tambaqui is the Brazilian name for Pacu;
It's come up in discussion before with a number of knowledgeable folks chiming in with their opinions:
John - here you go, you might need to brush up on your Portuguese....
Mulher.com 02/11/2011 - Tambaqui na Brasa - YouTube
Mulher.com 02/11/2011 - Tambaqui na Brasa. TVSECULO21 1334 videos. Subscribe Alert icon Subscribed. Sign In or Sign Up now ...
There are some comments on eating them in wikipedia. Apparently Teddy Roosevelt thought they were delicous and the Brzilian's like to eath the ribs. I have started my system with them but need to get another 50 or so. Do you happen to know of a source for them in the US. Preferably SE or Florida? Tx Hap Perry