Aega antarctica fish. It has strong muscles in its oesophagus and large salivary glands and rapidly fills its dilatable hind gut with blood. It then drops off the fish and spends several months on the seabed digesting the blood. In a research study, specimens of "Aega antarctica" were kept in a marine aquarium at the University of Oldenburg, Germany, where they were maintained at a temperature of . It was found that they would feed on a number of species of fish native to the North Sea and in this research they were fed on live European plaice ("Pleuronectes platessa"). One fish
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