I know the ingredients are almost identical between Hikari Massivore Delight and Hikari Sinking Carnivore but my 9" Tigrinus grew up eating sinking carnivore. I've been trying to feed it Massivore (broken into small pieces) for the past month but it just spits it out but gobbles up the carnivore. The two smell different also. I just thought I'd share this info.