stereome

Stereome refers to the amorphous, gelatinous layer found on the exterior of certain colonial marine organisms, most notably ascidians, also known as sea squirts. This extracellular matrix is secreted by the tunic cells of the colony and serves as a protective outer covering. The composition of stereome varies among different species but often includes water, cellulose, and various proteins and polysaccharides. It can range in consistency from soft and translucent to firm and opaque, and its color can also differ.

The function of stereome is primarily protective. It can shield the colony from physical damage, predation, and environmental stressors such as desiccation and UV radiation. In some species, the stereome may also play a role in the absorption of nutrients or in the attachment of the colony to a substrate. The development and structure of the stereome are genetically determined and can be influenced by environmental factors. Research into the stereome continues to explore its biochemical properties and its ecological significance for ascidian survival and community interactions.