FISHES OF THE GULF OF MAINE 



513 



this way to any great extent, for only traces of 

 plants have been found in their stomachs. 



The eggs of the European ocean pout (Zoarces 

 viviparus) are fertilized within the mother, and 

 are retained within her oviducts until after they 

 hatch. But the American eelpout lays eggs, as 

 proved by the fact that the young were hatched 

 from a mass of eggs brought up, with two eelpouts, 

 in an old rubber boot, 49 in Blacks Harbor, 

 Passamaquoddy Bay. And enough small speci- 

 mens of 1 }i inches and upward have been collected 

 of late, between New Jersey and Maine, to show 

 that the eelpout breeds successfully throughout 

 this part of its range, at least; and probably as far 

 north as northern Nova Scotia and the southern 

 side of the Gulf of St. Lawrence. 



Various lines of evidence *° show that spawning 

 takes place in September and October. And the 

 fact that fish taken in summer differ widely in tbe 

 stage of development of their sexual products 

 suggested to Clemens and Clemens that they do 

 not breed every year. But it seems more probable 

 to us that this is evidence simply of a protracted 

 breeding period, some individuals ripening early 

 in autumn, others not until later. 



Large females lay more eggs than small, tbe 

 numbers of maturing eggs actually counted having 

 ranged from 1,306 in a fish 21 % inches (55 cm.) 

 long to 4,161 in one of about M){ inches (87.5 cm.). 



The eggs are yellow, 6-7 mm. in diameter, and 

 are laid in masses held together by a gelatinous 

 substance. The only egg mass so far brought in 

 was in an old rubber boot, suggesting that they 

 are normally deposited in crevices in rocks or 

 among stones, which would explain the apparent 

 tendency of the mature fish to congregate on 

 rocky bottom as the spawning season approaches. 



The fact that eggs brought up in the trawl in the 

 Passamaquoddy region, where the spawning is sup- 

 posed to take place from mid-September through 

 October, hatched in early January, and that ocean- 

 pout eggs taken off New York in mid-November 61 

 still were some weeks short of hatching, makes it 

 likely that incubation occupies at least 2%. to 3 

 months. And the actions of a captive female 

 that lay coiled around its mass of eggs, though 



these had not been fertilized, 52 makes it likely 

 that the eggs are guarded by one or the other 

 parent during this period, perhaps by both of them. 



" For account, see White, Jour. Fish. Res. Bd. Canada, vol. 4, pt. 5, 1939, 

 pp. 337-33S. 



rt Discussed in detail by Olsen and Merriman, Bull. Bingham Oceanogr. 

 Coll., vol. 9, art. 4, 1946, pp. 69-77. 



" From the stomach of a cod, seo Olsen and Merriman, Bull. Bingham, 

 Oceanog. Coll., vol. 9. art. 4. 1946, p. 76, fig. 9. 



210941—53 84 



Figure 270. — Ocean pout (Macrozoarces americanus) . 

 Above, larva, 48 mm. Below, young fish, 387 mm. 

 Drawings by Louella E. Cable. 



The larvae are about 30 mm. long at hatching, 

 i. e., much larger than those of most of our com- 

 mercially important fishes, and they are so far 

 advanced already in development that they are 

 easily identified. 63 Being so nearly adult in form, 

 it is probable that they hold to the bottom from 

 the time they are hatched ; all catches of immature 

 fish recorded so far have, indeed, been on the 

 bottom. 



The sizes, of the fry in different months, show 

 that ocean pouts reach a length of about 3 inches 

 during their first summer, and that they are about 

 4 to 5 inches long when 1 ye&v old. According to 

 studies of otoliths by Olsen and Merriman, 64 ocean 

 pouts in southern New England waters may be 

 expected to reach 6 inches when between 1 and 2 

 years old; 12 inches at 3 years; and 24 inches when 

 between 6 and 7 years, the very large fish of 36 

 inches and upward being 12 years to 16 years old. 

 Estimates by the same method by Clemens and 

 Clemens 66 point, however, to a considerably 

 slower rate of growth in the colder water of the 

 Bay of Fundy, where a 12-inch fish is likely to be 

 nearly 5 years old, a 24-inch fish between 12 and 13 

 years old; and where the 8 oldest fish examined 



u See Olsen and Merriman (Bull. Bingham Oceanog. Coll., vol. 9, art. 

 4, 1946, p. 76, flg. 8) for a photograph of a female so employed, in the 

 Shcdd Aquarium, Chicago. 



" For further details, see White, Jour. Res. Board Canada, vol. 4, 1939, p. 

 338. 



» Bull. Bingham Oceanogr. Coll., vol. 9, art. 4, 1946, pp. 85-93. 



« Contributions to Canadian Biology, 1918-1920 (1921), p. 74. 



