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
Pseudorhombus arsius Pseudorhombus arsius Pseudorhombus arsius, the largetooth flounder, is a species of left-eyed flatfish, that is the dark side with the eyes on the adult fish is the left side of the fish's body, from the family Paralichthyidae. As "Rhombus polyspilos" it was named as the type species of the genus "Pseudorhombus". It is an Indo-Pacific species and is fished for by both recreational and commercial fisheries. "Pseudorhombus arsius" has an oval-shaped body which has a depth which is 1.8 to 2.3 times its standard length. The head has a slight notch in front of upper eye. The eyes are on