The Japanese flatfish, or Olive flounder, is a kind of the fish that belongs to the large tooth flounder suborder of the flatfish family. Its scientific name is Paralichthys olivaceus. The two eyes show it is lying on its right side with both eyes on the the left side.
Moreover, it has a feature that the mouth and teeth are big. It is distributed in the Pacific Ocean west (From the coast in the Kurile Islands, karahuto, Japan, and a Korean peninsula, etc. to the South China Sea). The flatfish grows to 1m in total length and about 10kg in weight in the maximum. The flatfish figure has both as right and left side types.
The flatfish lives in sands and the mud lake in the coast at night. It often conceals itself in sand and mud, only the head has been put out in daytime, and the color of the body is made the same color as bottom of the sea when not diving in sand.
The flatfish eats the fingerling, shellfishes, and the mussel worms that live chiefly at the bottom of the sea. The flatfish dives deeply in winter. And, it goes to the shoal of about 20cm in depth for the spawning time from March to July.
The egg is a floatage. The child was born from the egg is lucky also with normal eyes as long and slender as a usual fish. The movement of right eyes starts by about 1cm in the total length. It becomes the same type as parents when becoming about 2.5cm. It becomes an adult fish in about three years. Flatfish’s longevity is short for about several years.
The flatfish is high grade ingredients used for slices of raw fish and the sushi in Japan. Moreover, growth is quick, and geostationary at the bottom of the sea. Therefore, because oxygen is not very needed and seawater not made dirty, cultivation is active. It will be expected to circulate by a further low price considering the cultivation cost in the future.
The individual that doesn’t reach a certain size is discharged again for the resource conservation, and the discharge of the fry is done. The flatfish into which the fry is released doesn’t disappear by the pattern that the belly side is black even if growing up, and is called pandabirame. There are a lot of people who insists on the domination of the natural product who insist that the momentum at food influences the eating quality. The season of the flatfish is winter. It is said that the summer time after eggs is laid loses taste.
The flatfish is best seen in the Niyodo river in Kochi Prefecture.