糖胶层是对由细菌、上皮细胞，或其他细胞分泌的，覆盖在细胞表层的粘稠物的统称。鱼类表皮的粘液就是一种糖萼。这个名词的本意是指覆盖在上皮组织表面的，由上皮细胞分泌的多糖结构。

The glycocalyx is a glycoprotein-polysaccharide covering that surrounds the cell membranes of some bacteria, epithelia and other cells.

Most animal epithelial cells have a fuzz-like coat on the external surface of their plasma membranes. This coating consists of several carbohydrate moieties of membrane glycolipids and glycoproteins, which serve as backbone molecules for support. Generally, the carbohydrate portion of the glycolipids found on the surface of plasma membranes helps these molecules contribute to cell-cell recognition, communication, and intercellular adhesion.