When we get halibut at work, it's already cut into loins, off the bone, skin-on. I remove the skin, and cut it into pieces.
I've never processed saltwater fish that had any parasites on it. I've heard the swordfish is bad about tumors in the meat, but never seen it.
From what I've read, freshwater fish will get parasites, but as long as the meat is fully cooked, those parasites are killed and are not harmful. It's just unsightly.
Peace, Love, and Vegetable Rights!
Eat Meat and Save the Plants!