Beaches are full of seashells of all shapes and sizes. People have been collecting shells for hundreds of years. They make jewellery out of them, design art, use them as decorations and people have even used them as scoops and utensils before such things existed. Shells have fascinated people ever since they first washed up on shore and are still popular with beachgoers today.
Sea shells are the protective casing around sea creatures called mollusks. Unlike humans, mollusks have their skeletons on the outside of their bodies. When these creatures wash up on shore, they sometimes are eaten by other animals that pick away or make holes in the shell, to reach the meaty part of their dinner. Humans then collect the skeletal remains, or sea shells.
Types of Shells
Mollusks come in thousands of varieties. Just like people, mollusks look and feel different. They come in different colours, textures and sizes, making seashell collection unique and exciting. The look of a shell depends on the species of the animal that lived in it and the environment. Some types of shells commonly found are clam shell, starfish and hermit crab shells.
Colours and Patterns
The colour and pattern of a seashell is dependant on the diet and nutrition of its owner. In warmer waters, where food is plentiful, there are more varieties of shells, while colder habitats have fewer variations. Foods eaten by the mollusc create layers of pigment in the shell. Spiral, spotted or lines appear in the shell when a regular diet is changed or interrupted. The shell tells the history of the mollusc through the food it ate.
The shell is loosely attached to the mollusc and it does not create support, and as shells on beaches indicate, shells can be discarded. Shells grow periodically, not continually, and can grow in thickness on the surface of the shell or vertically out from the edges. Shells are sometimes used by mollusks as protection, or as a form of transportation for crawling, swimming or floating.