Abstract <p>Shell lesion, commonly known as “shell disease”, is common in crustaceans, including commercial species. Based on a number of grounds, the integumentary diseases are classified into erosive and non-erosive forms. The erosive shell disease is found in red king crab as in both northeastern and northwestern Pacific Ocean, the Bering and Okhotsk Seas, as in the Barents Sea. A non-erosive form of shell disease was discovered in red king crab in the Barents Sea in 2016. It differs from the erosive shell disease and various non-erosive forms described in the available literature by clinical and histological features. Mass outbreaks of this disease were recorded in 2016 and 2023.</p>