Question

What type of scales do Osteichthyes have?

Answer 1

Osteichthyes:

1. Osteichthyes are bony fishes, found in both marine and freshwater.
2. A small rigid plate that grows out of the skin of the fish is known as a fish scale.
3. The exoskeleton of Osteichthyes is made of scales - cycloid, ctenoid, or ganoid type.
4. Placoid scales are absent in them.

Cycloid scales:

1. Cycloid scales are uniform, have a smooth texture, large, thin, and oval in shape.
2. The outer edge of cycloid scales is smooth.

Ctenoid scales:

1. Ctenoid scales are similar to cycloid scales.
2. Except that they have small teeth called ctenii on the outer edges of the scales.

Ganoid scales:

1. Ganoid scales are similar to placoid scales.
2. Ganoid scales are covered with an enamel-like substance called ganoin.

Placoid scales:

1. Placoid scales are triangular, rough structures, with bony spiny projections.