FISHES OF THE GULF OF MAINE 361 



points along the Maine coast, at Portsmouth (N. H.), in Ipswich Bay, here and 

 there along the north shore of Massachusetts Bay, and at Provincetown. We 

 can add that it is to be found at Cohasset, Mass., and W. F. Clapp assures 

 us he has seen many while shore-collecting for mollusks among the stones and 

 bowlders of the Gurnet, off Plymouth, as well as at Hampton Beach, N. H., 

 while A. H. Clark, of the U. S. National Museum, reports it plentiful about 

 Portsmouth. No doubt it is even more universal, in suitable locations, than 

 these records indicate, for being of no consequence to the fisherman or angler it 

 comes to notice only when scientific collections are made, but it is certainly rather 

 local. In some places one is to be found under almost every stone; at others you 

 may turn rocks in vain. Its presence or absence along any particular stretch of 

 shore probably depends on the character of the bottom immediately outside, it 

 being a lover of pebbly, gravelly, or stony ground, or of shell beds and not of mud 

 or eelgrass. Nor have we found it about the steep ledges so numerous along rock- 

 bound coasts in the Gulf of Maine. 



Habits and food. — So far as known rock eels are confined to very shoal water, 

 most of them living within 2 or 3 fathoms of the surface, and perhaps none deeper 

 than 15 fathoms, 13 fathoms (near Woods Hole) being the deepest actual capture 

 with which we are acquainted, for which reason it is not likely that they occur on 

 the offshore Banks. They are often found along low tide mark, left by the ebb in 

 the little pools of water under stones or among seaweed where they await the 

 return of the tide. Many have been seined on gravel bottom in a few feet of water. 

 When uncovered they are usually lying partially coiled, and in Scandinavian waters, 

 according to Smitt, 15 they often take refuge inside large empty mussel shells, but, 

 as he remarks, there is no ground for the accusation that rock eels enter and devour 

 live bivalves of any sort. When disturbed they squirm like eels. Eel-like, they 

 swim by sidewise undulations, and they are so active and so slippery (hence the 

 name "butterfish") that it needs quick work to catch one by hand even in a very 

 small puddle. Very little is known of the diet of the rock eel except that it is 

 carnivorous and that various molluscan and crustacean fragments have been 

 found in its stomach. Vinal Edwards records small amphipods, shrimps, and worms 

 in the few examined at Woods Hole, but we have no first-hand information to offer 

 on this point. In their turn, rock eels have been found in the stomachs of various 

 larger fishes, especially of cod, in Massachusetts waters. 



So far as known the rock eel is resident throughout the year wherever found. 

 At most it may move out from the beach into slightly deeper water in winter to 

 escape chilling. 



Breeding habits. — It is necessary to turn to European sources for information 

 on its breeding habits, for its spawning has not been seen in American waters. 

 In the eastern Atlantic and North Sea region generally 16 it spawns from November 

 to February or even March, and since eggs probably belonging to the rock eel 

 have been found off Rhode Island late in December, 17 no doubt it is simdarly a 



'» Scandinavian Fishes, 1S92. 



» Masterman and Macintosh (The Life-Histories of the Bril ish Marine Food-Fishes, 1897) and Ehrenbaum ( Wissenschaftliche 

 Meeresuntersuchungen, Helgoland, ecup Folge, Band 6, 1901, p. 160) give accounts of its spawning and larval development. 

 lT Tracy, 1910, p. 151. 



