FISHES OF THE GULF OF MAINE 



433 



Food. — The diet of the Gulf of Maine rosefish 

 includes a great variety of crustaceans, especially 

 mysid, euphausiid, and decapod shrimps; small 

 mollusks; and various other invertebrates, and 

 small fish. 23 It bites on almost any bait. In 

 turn, it is the prey of all the larger predaceous 

 fish, its fry being devoured in quantity by cod, 

 by older rosefish, and by halibut. 



It has long been known that the eggs of the 

 rosefish develop and hatch within the oviduct 

 of the mother, and the number produced by large 

 females may run as high as 25,000-40,000 yearly. 

 This is a small brood compared to the numbers 

 produced by many of the marine egg-laying fishes. 

 But the protection offered the eggs by being 

 retained inside the mother's body during incuba- 

 tion gives the young a greater chance for survival. 



The larvae are about 6 mm. long at birth 

 (fig. 223B), with the yolk mostly absorbed, the 

 mouth already formed, and the first traces of 

 the caudal rays already visible. At a length of 

 12 mm. (fig. 223D) the dorsal and anal fin rays have 

 appeared, the ventrals are visible, and the head 

 spines are prominent. And though the red color 

 is not developed until the little fishes are about 

 to take to bottom, or later, all but the very young- 

 est larvae are recognizable as rosefish by their 

 large spiny heads, large eyes, short tapering bodies, 

 very short digestive tract, and by the presence 

 of two rows of post anal pigment cells, a dorsal 

 and a ventral row. 



This is a very slow-growing fish. Available 

 information is to the effect that they average 

 about 2}{ inches when 1 year old. 24 Studies of 

 the scales of rosefish of different sizes 25 indicate 

 that 5-inch fish are likely to be 4 years old; 

 6-inch fish, 6 years old; 7-inch fish 7 or 8 years 

 old; 8-inch fish 8 or 9 years old; 9-inch fish 9 or 

 10 years old, and that many of the largest fish 

 of 18 inches and upward may be 20 years old, 

 or older. Thus the mature fish are 8 to 9 years 

 old and older, with the greater part of the com- 

 mercial catch 10 years old and upward. And 

 about as slow a growth rate has been reported 



for the immature rosefish of this same species 

 of Barents Sea, on the other side of the Atlantic. 26 



~ 



« Most of the rosefish that we have seen trawled had voided their stomach 

 contents before tbe> were brought on board. 



3' According to the sizes of young rosefish collected by us in the Gulf of 

 Maine, May to August in various years. 



" By Perlmutter and Clark, U. S. Fish and Wildlife Service, Fishery 

 Bull. No. 45, 1949. 



Fioure 223.— Rosefish (Sebastes marinus). A, egg from 

 the oviduct of a gravid female; B, larva, mm.; C. 

 larva, 9 mm.; D, larva, 12 mm.; E, fry, 20 mm. Speci- 

 mens from Gulf of Maine. From Bigelow and Welshj 



General range.— Both sides of the North Atlan- 

 tic; northward to Spitzbergen, Nova Zembla, 

 Iceland, West Greenland, Davis .Strait, south- 

 eastern Labrador, coasts and Banks of New- 

 foundland, and Gulf of St. Lawrence; southward 

 to the offing of southern New England and as 

 far as the offing of New Jersey in deep water 

 along the American coast, 27 to the northern part 



" By Veschezerov, in Knipovitch, i'olar Sci. fnst. Sea Fisheries and 

 Oceanogr., No. 8, 1941, pp. 236-270 (Russian). 



« Tauing (Journal du Conseil Cons, Internat. Explor. Mer., vol. 16, 1949, 

 p. 86) is of the opinion that the Americau rosefish does not belong to the same 

 species as the European 5. marinus hence he refers to it as S. fasciatus, Storer, 

 1854. But our own comparison of good-sized specimens from the two sides 

 of the Atlantic has failed to show any differences that seem sufficient for 

 specific separation, whether in number of scales, in the spines on the cheeks, 

 in the fins, or in bodily proportions. We are much indebted to Dr. C. E. 

 Lucas for sending us a series of rosefish of various sizes that had been landed 

 in Aberdeen, Scotland. 



