roe substitute for hamaguri-zushi?

I'm having a dinner party on Saturday night, and I REALLY wanted to make some of those cute pink hamaguri-zushi as part of the first course. But can I find salmon roe, or for that matter ANY sort of fish roe, in any sort of shop? No I can't. I can't find fresh (the fish place said that season finished a couple of weeks ago), I can't find frozen, and I can't find it in little jars the way I have had it before. So, help Maki! What can I sprinkle on top of hamaguri-zushi that is not any sort of fish egg?