FISHES OF THE GULF OF MAINE 467 



In the rockling there is only one band of pigment behind the vent, and no definite 

 band in either of the hakes common in the Gulf of Maine. The first traces of the 

 vertical fin rays of the young cusk are visible at about 12.5 mm., and the dorsal 

 and anal fins are differentiated at about 28 mm., at which stage the ventrals are 

 relatively at their longest. Fry of 40 mm. and upward show most of the characters 

 of the adult, the relationship of the dorsal and anal fins to the caudal and the 

 presence of only a single dorsal and anal fin being sufficient to identify them as 

 such from this size on. 



The older cusk fry, while still living at the surface, are described by Schmidt ^' 

 as greenish yellow with blue eyes, not silvery-sided like young rockling and hake. 



The young cusk lives near the surface like other gadoids until it is 2 inches or 

 more long, and there is reason to believe that in European seas they first seek the 

 bottom in considerable depths, but we have nothing to offer on this point for the 

 Gulf of Maine. 



Commercial importance. — The cusk is an excellent food fish and there is a 

 ready market for all that are caught. 



THE GRENADIERS. FAMILY MACROURID.S 



The grenadiers are characterized externally by large heads, projecting snouts, 

 and slender bodies tapering to whiplike tails with no definitely demarked caudal 

 fin. There are two dorsal fins — the first high and the second very low, but occu- 

 pying the greater part of the back — and there is an even longer anal. The grena- 

 diers are now universally located close to the cod family in classification because 

 of the structure of their skulls, but unlike that tribe there is one stout spine in the 

 first dorsal fin. They are deep-sea fishes, living on the bottom, loose in texture 

 and weak swimmers. Many species are known, but only three have ever been taken 

 within the confines of the Gulf of Maine. 



Besides the species described below, three others — CorypTisenoides rupestris, 

 C. carapinus, and Hymenocephalus goodei — have been taken sufficiently often on 

 the continental slope abreast of the Gulf and off southern New England to show 

 that they are not uncommon below 500 fathoms, but they are all typical inhabi- 

 tants of the deep-sea floor and never likely to rise into shoal enough water to come 

 within the limits of the Gulf of Maine.^* 



KEY TO GULF OF MAINE GRENADIERS 



1. Dorsal spine perfectly smooth; snout projects considerably beyond the mouth 



Long-nosed grenadier (Coelorhynchus carminatus), p. 471 



Dorsal spine serrated with teeth which can be felt if not seen; snout projects only 

 slightly beyond the mouth 2 



2. Dorsal spine strongly serrated Common grenadier {Macrourus bairdii), p. 468 



Serrations on dorsal spine so fine as to be hardly visible 



Smooth-spined grenadier (M. herglax), p. 470 



s' Meddelelser fra Komimssionen for Havundersjlgelser, Serie: Fiskeri, Bind I, No. 8, 1905, p. 7. He also describes the larval 

 stages of the cusk. 



>' For descriptions of ttiese and lists of the localities at which they have been taken see Qoode and Bean (1896). 



