Re: Smoking seaweed?
You are spot on. Rather than "intelligent" behaviour, this sounds like opportunistic hunting, a quite common behaviour under water. I have seen jacks swimming with sharks and stingrays, hoping to catch some morsels (from the sharks) or small fry (stirred up by the rays). Once I observed a jack that had turned yellow (which I didn't know they were able to do) to blend in in a school of grunts.