RV Platessa tagged plaice were released off the Cumberland coast, using the RV "Platessa" during 1949 and 1950. In August 1951 echo-sounder traces were obtained over a wide area off Whitby by the RV 'Platessa', using a Marconi sounder. They were found to occur at a depth corresponding to that of a sharp thermocline, and small whiting about 3 in. in length, large Medusae, herring and sandeel larvæ were caught with a pelagic trawl at the depth of the trace. This work was reported in a ‘letter’ to the journal Nature in 1952. In 1950 the RV "Platessa" was involved in comparative
Flatfish flatfish). The primitive spiny turbots include equal numbers of right- and left-sided individuals, and are generally less asymmetrical than the other families. Other distinguishing features of the order are the presence of protrusible eyes, another adaptation to living on the seabed (benthos), and the extension of the dorsal fin onto the head. The surface of the fish facing away from the sea floor is pigmented, often serving to camouflage the fish, but sometimes with striking coloured patterns. Some flatfishes are also able to change their pigmentation to match the background, in a manner similar to some cephalopods. The side of