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
Ide (fish) of other cyprinids, but the larger adult fish form smaller single species groups which patrol what are believed to be regular routes. The ide prefers clear, warmer water and is not as tolerant of eutrophication as some related species. Ide spawn in running water and this means that the obstruction of rivers by dams and other man-made objects can negatively affect this fish. As an ornamental fish the ide is usually referred to as the orfe and the main variety kept is the golden orfe, which is golden or orange in colour with some black spots on its neck, near