Use them for cosmetics, foods or drugs
Akiko Masuda of the Institute of Physical and Chemical Research in Saitama and colleagues have extracted a previously unknown glycoprotein—a repeating sequence of amino acids with sugars attached—from jellyfish. The compound is a type of mucin, a gelatinous, moisture-retaining substance secreted by animals (it’s a main component of human saliva and mucus, for instance), and it could find uses in cosmetics as a food additive or in drug manufacturing. Since jellyfish mucin has a simpler structure than some other mucins, it may be usable as a building block for creating custom-tailored mucins with antibiotic or other specific properties.
 
The researchers, who reported their findings in The Journal of Natural Products, extracted the mucin from several species including the moon jellyfish (Aurelia aurita, one of the most abundant in the world) and Nemopilema nomurai, one of the biggest, at up to six feet in diameter and 450 pounds. They found that the mucin made up as much as three percent of the dry weight of jellyfish. So, there is an awful lot of mucin in the world as well.