A Fibrous Protein From the Slime of the Hagfish

The hagfishes are well known for the copious amounts of slime, or "mucus," which they secrete when disturbed or annoyed (1).In sea water, a hagfish can produce in a few seconds several times its own volume of slime.The slime is colorless and transparent, and, although extremely dilute, has a tough, coherent, stringy consistency.It is highly viscous, and also possesses rigidity, exhibiting "elastic recoil."This material, obtained from the Pacific hagfish, Polistotrema stouti, has now been examined in connection with a general study of mechanical properties of protein, mucoprotein, and polysaccharide systems.It has been found to be heterogeneous in composition, containing insoluble protein fibers which are largely responsible for its peculiar consistency.The present paper describes the microscopic structure of the slime and the composition of the fiber protein.Materials-Specimens of Polistotrema stouti were obtained from Monterey Bay.The animals survived for several weeks without food in tanks of running sea water, and could be stimulated repeatedly for the production of slime.I am greatly indebted to Dr. Berry Campbell for advice and aid in the handling of hagfish and in devising suitable methods of stimulation.Behavior of Slime Secreted in Sea Water-The animals were stimulated in sea water by agitation or local pressure.The voluminous transparent slime thus produced contained a loosely tangled mass of fibers, each about 1.3 fi in diameter and several cm.long.