Demersal fish flounder, sole, turbot, plaice, and halibut. The adult fish of many species have both eyes on one side of the head. When the fish hatches, one eye is located on each side of its head. But as the fish grows from the larval stage, one eye migrates to the other side of the body as a process of metamorphosis. The flatfish then changes its habits, and camouflages itself by lying on the bottom of the ocean floor with both eyes facing upwards. The side to which one eye migrates depends on the species; with some species both eyes are ultimately
RV Platessa in survey logbooks, collected in 1931, 1937, 1946–50, and 1968. These historical measurements have revealed that the ‘sechhi depth’ was much deeper (and therefore water more transparent) in the past compared to today, and thus that the North Sea has become much more turbid. The Suffolk Record Office holds a photograph captioned ""survey ship "Platessa" LT 205 in Lowestoft harbour after being escorted back by the Gorleston lifeboat Khami having sprung a leak whilst working in the Smiths Knoll area"", dated 5th October 1968 (after leaving MAFF service). RV Platessa RV "Platessa" (LT205) was a fisheries research vessel that was