RV Platessa the central basin. The RV "Platessa" (LT205) was in service with Ministry of Agriculture, Fisheries and Food (United Kingdom) from April 1946 until June 1967, during which time she participated in more than 473 separate research campaigns. She was primarily confined to the southern North Sea, but with occasional forays into the Irish Sea and English Channel, especially in the 1960s. The RV "Platessa" (LT205) was overwhelmingly dedicated to research on North Sea herring and North Sea Plaice. This work included the tagging of more than 12,000 plaice during the 1950s, 7000 during the 1960s. In addition, large numbers of
Black spot disease (fish) after leaving the snails they burrow into the skin of fish and form a cyst. The fish surrounds the cyst with black pigment that gives the disease its name. If an infected fish is consumed by a bird, the cycle repeats itself. Black spot disease (fish) Black spot disease is also known as diplopstomiasis or fluke disease. It is a freshwater fish disease caused by flatworm larvae of the genus "Neascus". It appears as tiny black spots on the skin, fins and flesh of the fish. The life cycle of the parasite typically involves a fish-eating bird, a snail and