Flatfish entire order was John Roxborough Norman's "Monograph of the Flatfishes" published in 1934. New species are described with some regularity and undescribed species likely remain. Hybrids are well known in flatfishes. The Pleuronectidae, of marine fishes, have the largest number of reported hybrids. Two of the most famous intergeneric hybrids are between the European plaice ("Pleuronectes platessa") and European flounder ("Platichthys flesus") in the Baltic Sea, and between the English sole ("Parophrys vetulus") and starry flounder ("Platichthys stellatus") in Puget Sound. The offspring of the latter species pair is popularly known as the hybrid sole and was initially believed to
RV Platessa RV Platessa RV "Platessa" (LT205) was a fisheries research vessel that was operated by the Ministry of Agriculture, Fisheries and Food (United Kingdom) - Directorate of Fisheries, now known as the Centre for Environment, Fisheries and Aquaculture Science (Cefas) between 1946 and 1967. RV "Platessa" was based at the port of Lowestoft and was originally ordered by the Admiralty as one of 81 Motor Fishing Vessels (MFVs) in the ‘1501-Class’ during World War II. Motor fishing vessels were small wooden craft, built in large numbers during the war for use as Ship's tenders. Constructed as MFV 1576 by East Anglian