470 BULLETIN OF THE BUREAU OF FISHERIES 



Habits.— Tittle is known of the habits of the grenadier except that it is a bottom 

 fish, usually found on soft mud, and a very feeble swimmer, while Hensen's 40 report 

 of pelagic euphausiid shrimps (Thysanoessa longicaudata) in a grenadier stomach 

 is the only observation which has so far been made on its diet. 



Probably grenadiers spawn in summer and autumn, for the spermaries of the 

 specimen from the western basin of the Gulf, just mentioned, were nearly ripe on 

 August 19, but neither the eggs, larva?, nor young fry of this fish have been seen. 

 The former, however, probably resemble other macrurid eggs described by European 

 authors; 41 that is, they are buoyant at least for the first part of incubation, with a 

 large oil globule, wide perivitelline space, and sculptured on the surface into concave 

 hexagonal facets. Larval macrurids of other species have the rays of the first 

 dorsal and ventral fins much elongated. 



163. Smooth-spined grenadier ( Macrourus be rglax Lacepede) 

 Rat-tail; Onion-eye 



Jordan and Evermann, 1896-1900, p. 2581. 



Description. — This species so closely resembles the common grenadier (p. 468) 

 in its general appearance that we need only point out the points of difference. 

 Most obvious of these are that its snout is shorter and blunter, with more highly 

 arched dorsal profile; that there are from 4 to 6 distinct ridges on the top of the head; 

 that the trunk is relatively stouter (about 6 or 7 times as deep as long) ; and that the 

 serrations of the second ray of the first dorsal fin are so much finer as to be hardly visi- 

 ble. Furthermore there are fewer (about 124) rays in the second dorsal fin, more 

 (about 148) in the anal, and the first dorsal is of rather different outline than in the 

 common grenadier. The second dorsal is relatively higher and with its membrane 

 more developed (compare fig. 236 with fig. 235) , while none of the authors who have 

 described this grenadier (we have never seen it) have mentioned any filamentous 

 prolongation of the ventral fin such as occurs in Macrourus bairdii. The structure 

 of the scales is also diagnostic, though visible only under a lens, for those on the 

 body of the present species are described as armed with one median or with two 

 lateral ridges of spines whereas in M. bairdii there are 10 to 12 rows cf spines on 



each scale. 



Color. — No information is available as to the color of this fish in life. 



Size.— Larger than the other grenadier (p. 468) , being credited with a maximum 

 length of 3 feet and a weight of 4 or 5 pounds. 



General range and occurrence in the Gulf of Maine.— This is a deep-water fish 

 like its relative but more northerly in its distribution, being known off northern 

 Norway, Spitzbergen, Iceland, southern Greenland, in Davis Strait, and southward 

 along the continental slope of North America as far as Georges Bank. One has 

 even been found dead, floating on the surface, off New York Harbor. 



<° Proceedings, U. S. National Museum, vol. 48, 1915, p. 99. 



•i Ehrenbaum (Nordisches Plankton, Band 1, 1905-1909) summarizes what little is known of the eggs and young of this group 

 of fishes. 



