In one episode of Chopped, a contestant used freshwater fish in a carpaccio (a dish made with raw meat). When it was presented, the judges refused to eat it. They tried some of the side dishes, but would not touch the raw freshwater fish due to concerns with parasites/bacteria. The contestant was, of course, removed from the competition.
Oh, I’d love to see that! Do you know what season by chance? And what episode?
Yes, reading the OP I assumed (and we all know what makes me!) the OP and some others were referring to sushi with raw fish. My apologies for the harsh post.
As to what is sushi, to my understanding, it’s the prepared vinegar rice:
Sushi (すし, 寿司, 鮨, 鮓, pronounced [sɯɕiꜜ] or [sɯꜜɕi]) is a Japanese dish of prepared vinegared rice (鮨飯, sushi-meshi), usually with some sugar and salt, accompanied by a variety of ingredients (ねた, neta), such as seafood, often raw, and vegetables. Styles of sushi and its presentation vary widely, but the one key ingredient is “sushi rice”, also referred to as shari (しゃり), or sumeshi (酢飯).[1]
https://en.wikipedia.org/wiki/Sushi
Rice without vinegar (with or without sugar and/or sugar) is mususbi/onigiri even if topped with something ala nigiri sushi.
I don’t know if the link will take you directly to the correct page, but Genki Sushi in Hawaii has Spam, hotdog and corn sushi along with the other usual offerings: https://www.genkisushiusa.com/menu#regions
I’ve had the Spam sushi and it’s not bad!