Good point, Barry! Sollozzo sent the fish wrapped in Luca's bulletproof vest for maximum shock value. The real "Sicilian message" was that "you lost your atomic weapon." Michael is juxtapositioned nicely there. He wants to help, Sonny says, "no, no, the old man'd have my head," then says Michael could "hang around the phone, be a big help..." But after the dead fish, no more telemarketing for Michael.