The hagfish is known for producing slime that can clog a predator’s gills.
When attacked, hagfish release mucus and long protein fibres from glands along their bodies. In seawater, this material rapidly expands into a thick slime. It can interfere with a predator’s breathing by obstructing the gills, giving the hagfish time to escape.
Hagfish are eel-shaped marine animals, but they are not true eels. They are jawless vertebrates and are closely related to lampreys. Their unusual feeding method often involves entering dead or dying animals through openings and rasping away tissue with tooth-like structures on a specialized tongue.
Hagfish can also tie their bodies into knots. This helps them remove slime and provides leverage while feeding. Their slime fibres have attracted scientific interest because they are strong, lightweight and potentially useful in engineered materials.