FISHES OF THE GULF OF MAINE 



91 



zone, nor has herring spawn ever been reported as 

 cast up by the surf on the beaches of New England, 

 a fate that often overtakes it in the Gulf of St. 

 Lawrence. Occasionally they spawn as deep as 

 100 fathoms in Scandanavian waters, perhaps also 

 in the eastern basin of our Gulf where the sea floor 

 is hard, not soft and muddy as it is in the basins in 

 the western side. During the act of reproduction 

 as observed by Moore at Cross Island and at 

 Machias, Maine, "the fish were darting rapidly 

 about, and those who have opportunity to see the 

 fish spawning in more shallow water where ob- 

 servation is more favorable, state that both males 

 and females are in constant motion, rubbing 

 against one another and upon the bottom, appar- 

 ently by pressure aiding in the discharge of the 

 eggs and milt." 32 



A female herring may deposit from 20,000 to 

 upwards of 40,000 eggs, according to her age and 

 size, averaging about 30,000. In sexually mature 

 herrings, the genital organs are so large just before 

 spawning commences that they make up about 

 one-fifth the total weight of the fish. 



The eggs sink to the bottom, where they stick 

 in layers or clumps to the sand or clay, to sea- 

 weeds, or to stones, by means of their coating of 

 mucus, or to any other objects on which they 

 chance to settle. They are often found massed 

 on net warps, anchors, and anchor ropes. The 

 individual eggs are 1 to 1.4 mm. in diameter, de- 

 pending on the size of the parent fish and also, 

 perhaps, on the local race of fish involved. The 

 period of incubation is governed by temperature; 

 European students tell us that it requires as long 

 as 40 days at 38-39°, 15 days at 44^6° and 11 

 days at 50-51° F.; while experiments on the Mas- 

 sachusetts coast by the U. S. Bureau of Fisheries 

 gave 10 to 12 days in the temperature prevailing 

 there in autumn. And MacFarland 33 found that 

 all of the eggs kept at Grand Manan at about 59 ° 

 (15° C.) hatched, but that none hatched at 32-41° 

 (0-5° C), and that all died that were warmed to 

 68° (20° C.). Ten to fifteen days might be stated 

 as an average incubation period for the Gulf of 

 Maine, under existing temperatures. 



The larvae of the herring family are very slender 

 and can easily be distinguished from all other 

 young Gulf of Maine fish of similar form (e. g., 

 launce, smelt, or rock eel) by the location of the 



» Moore, Rept. U. S. Comm. Fish. (1896), 1888, p. 412. 

 » Rept. Biol. Board Canada (1930), 1931, p. 23. 



Figure 42. — Eggs of the herring (Clupea harengus), 

 attached to seaweed (European). After Ehrenbaum. 



vent, which is so far back that it lies close to the 

 base of the tail. But it requires critical examina- 

 tion to distinguish our several clupeoids one from 

 another in their early stages. 



The sea herring is about 5 to 6 mm. long at 

 hatching, with a small yolk sac that is absorbed 

 by the time a length of about 10 mm. is reached. 

 The dorsal fin is formed at 15 to 17 mm.; the anal 

 at about 30 mm.; the ventrals are visible and the 

 tail well forked at 30 to 35 mm. ; and at about 40 

 mm. (1% in.), the little fish begins to look like a 

 herring. 



According to Huntsman's observations, fry 

 produced on the Grand Manan spawning grounds 

 in late summer and early autumn grow to a length 

 of 17 to 20 mm. by the end of November or first 

 of December; they are 26 to 50 mm. (1-2 in.) long 

 in March and April and 50 to 60 mm. (2-2% in.) 

 long by June when fry of this size are abundant 

 in the St. Andrews region. This is in line with 

 our own observations that fry of 2 to 2% inches 

 (50-65 mm.) predominate among the young her- 

 ring at Provincetown at the end of June, and fry 

 of 2% to 4 inches (54 to 100 mm.) on Nantucket 



