The Gelidiaceae is a small family of red algae containing eight genera.

[1] Many species of this algae are used to make agar.

[2] Agar can be derived from many types of red seaweeds, including those from families such as Gelidiaceaae, Gracilariaceae, Gelidiellaceae and Pterocladiaceae.

It is a polysaccharide located in the inner part of the red algal cell wall.

It is used in food material, medicines, cosmetics, therapeutic and biotechnology industries.