Yesterday I bought a piece of smoked cod fillet. I didn't feel hungry, so I thought I would save it for today, and I placed it on top of the cooler. I forgot to put it inside, and went to bed. I woke up in the middle of the night, and I noticed a blue light - it was the cod, and the whole piece was emitting the light. I have never seen this before, and I checked on Wikipedia -
https://en.wikipedia.org/wiki/BioluminescenceI notice this phrase - "Aposematism is a widely used function of bioluminescence, providing a warning that the creature concerned is unpalatable."
I don't think I am going to eat it, and I will take a photo tonight and ask the supermarket to comment. My scientific knowledge is a bit limited and focused, so I would be interested in some comments from the more learned members here.