I have been getting my tuna for sashimi frozen, but a local sushi chef tells me it is much better fresh.
A local seafood outlet, which supplies many local restaurants and has an excellent reputation, has fresh "sushi grade" yellowfin tuna, but tells me it should be frozen for at least an hour before it can be served raw. The manager says he has a number of "sushi grade" species, but says they all should be frozen first. And he says the fresh cobia should not be eaten raw at all.
I want to eat it fresh, but am concerned. Is it required to freeze fish before serving it as sashimi? And is Cobia not suitable as sashimi at all?