Question

What is the purpose of scales?

Answer 1

Scales:

1. Scales are small plate dermal or epidermal structures found in the outer skeleton of fish, reptiles, or some mammals.
2. The skeletons of many vertebrates are covered with two types of scales, the epidermis, and the dermis. Epidermal scales arise from the scaly layer of the epidermis.
3. These scales are found in terrestrial vertebrates such as reptiles, birds, and mammals. Then, skin scales emerge from the fish's dermis.
4. These scales consist of small, thin, spiny, crushed, or adherent bony plates. The outer skeleton of a fish is called a scale. The body of an ideal fish is covered with fine scales.
5. Fish scales can be divided into four types based on their shape, which are placoid, cycloid, ganoid, and ctenoid.

Purpose of scales:

1. Fish scales mainly serve two purposes: protection and locomotion.
2. The animal skin is defended by scales from predators and the environment.
3. Bone from the deeper, or dermal, skin subcaste is used to make fish scales.
4. Placoid scales are bony, spiky bulges with an enamel-like covering seen on elasmobranchs (similar to sharks).

Types of fish scales:

Cycloid scales:

1. Cycloid scales are uniform and have smooth textures.
2. Cycloid scales are large, thin, and oval in shape
3. The outer edge of cycloid scales is smooth.
4. Example: Carp.

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.
3. Example: Perch, sunfish.

Placoid scales:

1. Placoid scales are triangular rough structures, bony spiny projections.
2. Placoid scales are present in cartilaginous fish.
3. Example: Sharks.

Ganoid scales:

1. Ganoid scales are similar to placoid scales.
2. Ganoid scales are covered with an enamel-like substance called ganoin.
3. Example: Gars, bowfin.