Fish – How to tell if fish is subjected to Ciguatera

General food safety guidelines give you four hours of time between 40F and 140F; more than that, and unsavory bacteria exceed nominally safe limits.

So, there's your safety limit. Total time counts, that is, in a bag back from the grocer for 2 hours, then in the fridge and back down to 34F and then out for 1 hour on the counter = 1 hour left until it needs to go over 140 for ten minutes (or 165 for 1 minute) or into your mouth.

And of course, there's the amount of time it was left on the dock, etc. etc.

That said, if you left fish in the fridge for a week, it would be mushy and bad tasting raw -- so you also must use your tastebuds and nose to see if you want to eat it raw; food safety isn't the only concern.

As a rule of thumb for a whole fish, and not a fillet -

• the gills should be bright red
• the skin/scales should be bright and shiny like metal
• this fish shouldn't really smell of anything except 'watery'
• the flesh should rebound quickly when pressed
• the eyes should be bright and clear
• really fresh fish is also quite slimey to touch if it's straight out of the water. I remember being quite surprised at this from my first fishing trip a few years back.