All raw salmon is frozen for a minimum of 3 weeks, and then can be sold for sushi or as sashimi, as
certain kinds of worms and pathogens can not survive the long - term freezing.
The unfertilized eggs
of some animals (small invertebrates,
worms, some species
of fish, lizards and frogs) can develop into full - grown adults under
certain environmental conditions — usually a chemical stimulus
of some
kind.