Note that ceviche is a different class of "raw" than e.g. sushi, in that the lime juice does kill _some_ (but not all) parasites. According to https://honest-food.net/ceviche-recipe-safety-parasites-2/, fresh farmed salmon is ok to eat raw, while pacific salmon is pretty risky, on the basis of it being susceptible to seal worm. The article mentions a long freeze (at -4F) being an acceptable way to kill off those parasites before consumption.