a grey sea slug between a sea star and a soft coral

nudibranch fjord oslo fjord sea life arctic parasitic nudibranch rhinophore cerata gills pink slug marine life cold sea dark water subarctic norwegian marine life macro scandinavian sea slugs life fjords cold water diving parasite symbiosis pedata splachnotrophus opisthobranch stinging cells beautiful slug grey aeolidia papillosa seastar starfish brittle star coral soft