Hikari Crab Cuisine
Okay, finally found this stuff.
Shrimp like it.
Fish like it MORE. Endlers and Formosa went ballistic, like a pack of wolves, over the two pellets I dropped in it - actually biting it while it was in the clutches of shrimp and robbing it away in the end.
I'm guessing this stuff is a bad idea in a mixed tank and is meant for species tanks, eh?