My friend has one that is about 7" now and it is housed with a Jack Dempsey, Bichir and a Buttokofri. The Jack Dempsey is about 6" and the Buttokofri is about 8", they don't bother the Freshwater Barracuda at all and they are pretty agressive fish.
I figure both will give the barracuda a good work out. I'm contemplating about a austrialian aro as tankmate. Would sure hate to have my prize possession injuried.
i have a fresh water barracuda about 8 inches and i think your fish will be safe if they are big enough not to be eaten by fwb ie wont fit in its mouth as they swallow their prey hole.one other thing is you will need to feed the barracuda live fish as i dont think they will eat anything else, well mine wont and i have tried everything.
Thanx for the replies. I was thinkin of having it as a tankmate for an Australian Aro but since I prefer not to include feeders in the diet, the barracuda won't work if it only dines on feeders.