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
Lemon sole Lemon sole The lemon sole ("Microstomus kitt") is a flatfish of the family Pleuronectidae. It is native to shallow seas around Northern Europe, where it lives on stony bottoms down to depths of about . It grows up to in length and reaches about in weight. It is a popular food fish. The lemon sole is a right-eyed flatfish with a small head and mouth and smooth, slimy skin. The upper surface is reddish brown in colour, mottled with pink and orange and flecks of yellow and green, and a prominent orange patch is typically found behind the pectoral fin,