The stone-like thing in the circle of the fish is fish scales.

Flounder, a kind of flounder. The body length is oval, oval or rhombic, with a flat side and a short and high tail stalk. The edge of the anterior branchial operculum is free. The body is flat and asymmetrical, and both eyes are located on the right side of the head, and the maximum length is about 3 m.

Extended data:

Carassius auratus is widely distributed in the temperate zone of the Indian Ocean, the Pacific Ocean and the Atlantic Ocean, and near the subtropical sea. Very few species live in the Arctic region, and some species can swim into harbors and rivers.

The flatfish generally live in the shallow sea bottom of sediment, and some live in deeper water. For example, the tile flounder, which is found in the North Atlantic and the Indian Pacific, has also been found at the depth of 1628 meters. Feeding at night, generally not much activity during the day. Stay away from the coast in winter and spend the winter in deep waters; In the spring and summer of the following year, they swam to the coast for reproduction and bait-seeking activities. In the early stage, the larvae have their eyes on their sides and live in a floating life. Metamorphosis occurs in the development process, and the left eye gradually moves to the right. Once the metamorphosis is completed, it turns to benthic life.

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