Wow. Not even guppies! It's consistent though so far with what I saw with my vultures. They have been scavengers, not predators for me, except two unlikely but theoretically possible exceptions:
-- Once they took down a black ear pangasius catfish (they were ~10"-13" and the black ear was ~5"-6") which has had a long string of problems adjusting in a 4500 gal, often freaking out, knocking itself half-conscious, etc. The black ear once found its way into a sump through a drain grate with 1" holes. I've fished it out of the 500 gal prefilter and put it back into the 4500 gal. When passing by in 5-10 min later, I saw the vultures finishing it off. I can only assume that ether they killed it or they attacked it when it was half dead from injuring itself.
-- When I went to Dayton, Ohio to Gerber's in Mar 2016 for a rescue mission, I've bought a similar sized black ear from there too. Released it into the same 4500 gal. Within an hour (could have been minutes) it was food for the vultures. Again, I didn't catch them kill it, so the same possibility as above remains that the black ear freaked out, knocked itself out / half out and only then the vultures moved in. IDK.
In the first case, I've released two black ears into the 4500 gal. The other one is still there today, probably ~10", doing relatively well. Used to be a nervous wreck too, just less so than the black ear that perished. Much better now. Black ears IME are as nervous as fish can get. Their common cousin IDS has nothing on them when it comes to skittishness. It is not uncommon for black ears to convulse lying on the bottom and swim around erratically hitting things, jumping out of the water for some time after just having been released into a new home or after shipping.
I've bought 5 of them.
Two 3" from Sam (fishonlinerus) - both came in half dead and died shortly thereafter in acclimation (albeit now I think they could have simply been overcome with a panic attack and I got scared and acclimated them too fast).
Another two again from Sam at 4"- successfully acclimated, raised to ~5"-6", then transferred into 4500 gal where one perished, one's alive.
One ~5" from John Gerber - it perished.
So 1 for 5.
******
So I conclude that the vultures must have taken the two black ears down when those were not able to swim away or defend themselves, because if they had a tooth for black ears, the one doing well right now would not be here.
This is consistent with their reputation as ultimate, indiscriminate, and efficient opportunistic scavengers, such that they even try to scavenge a hooked fish... and even when a hooked fish is pulled out of the water, some vultures don't let go still.
An Opportunistic Scavenger.