Is crayfish vegetarian-compatible?

Watch for

• Tropomyosin is the dominant crustacean allergen and it is highly conserved, so crayfish, prawn, crab, lobster and langoustine cross-react as a group.Freshwater does not mean a different allergen: if crustaceans are off the list, crayfish are off the list
• The boil does more than the crayfish.Crab and crawfish boil blends are built on cayenne and paprika (nightshade), celery seed or celery salt, mustard, bay and garlic, and the pot usually also holds sausage, corn and potatoes. Crayfish are graded A on nightshade and A on fructans, so a boil reaction is very often the seasoning rather than the shellfish
• Crayfish absorb the boil liquid while they soak, which is the whole point of the technique.That means the seasoning is inside the tail meat, not just on the shell, and rinsing does not undo it
• The yellow paste in the head, the part people suck out and call the fat, is the hepatopancreas, the same organ as lobster tomalley.It is a filtering and storage organ and it concentrates cadmium and other contaminants far more than the tail muscle does
• Moderate in histamine (graded B), and it climbs fast in a crustacean that died before it was cooked.The old rule at boils, that a straight tail means it went into the pot dead and should be thrown away, is a freshness rule worth keeping