10 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Hagfish Myxine glutinosa Linnaeus 1758 

 Bigelow and Schroeder, 1948, p. 34. 



Description. — The hag, like the lamprey, lacks 

 paired fins and fin rays. Its skeleton is wholly 

 cartilaginous, without bones, its mouth is jawless; 

 and its skin is scaleless. It is easily recognized 

 by its eel-like form; by its single finfold (a fold 

 of skin, not a true fin) running right around the 

 tail and forward on the lower surface of the body 

 with no division into dorsal, caudal, and anal fins; 

 by the single gill pore on each side, just forward 

 of the origin of the ventral finfold; by its lipless 

 mouth, star-shaped in outline when closed; by 

 the single nasal aperture at the tip of the snout; 

 by its peculiar barbels or "tentacles," two flanking 

 the mouth on either side and four surrounding 

 the nostril; and by the evertible tongue studded 

 with rows of horny rasplike "teeth." We might 

 also mention the series of mucous sacs on either 

 side of the abdomen, and point out that the dorsal 

 finfold originates about two-thirds of the distance 

 back from snout toward tip of tail, and the ven- 



tral fin fold one-third the way back, with the vent 

 piercing it. 



Color. — Hags vary in color, perhaps to cor- 

 respond with the color of the bottom, being gray- 

 ish brown or reddish gray above, variously suf- 

 fused, mottled, or piebald with darker or paler 

 gray, with brown, or with bluish; they are whitish 

 or pale gray below. 



Size. — Gulf of Maine hags grow commonly to a 

 length of about 1% to 2 feet, with a maximum of 

 31 inches recorded off the coast of Maine. 



Habits. — The hag is found chiefly if not ex- 

 clusively where the bottom is soft mud, where (to 

 judge from its actions during the brief time it 

 survives in aquaria) it spends its time lying em- 

 bedded in the clay or mud with the tip of the 

 snout projecting. And it is at home only in com- 

 paratively low temperatures, cooler probably, 

 than 50°, which confines it in summer to depths 

 of 15 to 20 fathoms or more hi the Gulf of Maine. 

 It is not a true parasite, as has sometimes been 

 suggested, their being no reason to believe it ever 

 attacks living, uninjured fish, but is a scavenger. 



Figure 2. — Hagfish {Myxine glutinosa). A, adult, Gulf of Maine, from Bigelow and Schroeder, drawing by E. N. Fischer. 

 B, lower view of head of same; C, tongue-teeth of same as seen from above, about 3 times natural size; D, egg, 

 after Dean, about 2 times natural size. 



