FISHES OF THE GULF OF MAINE 



293 



that they commence spawning still earlier in the 

 season to the westward and southward, for Nichols 

 and Breder 8 report young fry 20 mm. long in Sandy 

 Hook Bay by May, while the sizes of the young 

 fry taken in winter in Chesapeake Bay suggest 

 that they are hatched there as early as March 

 or April. 9 



It is not yet possible to state the extremes of 

 temperature within which the sand flounder 

 spawns. But 50° to 60° F. has proved favorable 

 for hatching artificially fertilized eggs at Woods 

 Hole, with even 70° not too warm for successful 

 incubation. The eggs are spherical, transparent, 

 buoyant, 1 to 2 mm. in diameter (measurements 

 taken at Gloucester by Welsh), with a single color- 

 less or pale-lemon oil globule of 0.15 to 0.28 mm. 

 And the surface of the egg shows faint irregular 

 markings. Incubation occupies about 8 days at 

 51°-56°; its duration has not been recorded for 

 higher temperatures. The sand flounder, like the 

 winter flounder, completes its metamorphosis 

 while it is smaller than either the yellowtail (p. 273) 

 or the witch (p. 287). Thus the dorsal and anal fin 

 rays were complete and the ventral fins had formed 

 in one only 8K mm. long (fig. 153), and its right-hand 

 eye had already moved around to the back-line 

 of the head, while the migration of the eye is com- 

 pleted, and they are ready to take to bottom by 

 the time they have grown to 10 mm. long. 10 



Rate of Growth. — It seems that the sand flounder 

 passes through its larval stage more rapidly than 

 most flatfishes do, for many of its fry with the 

 migration of the eye completed have been taken 

 at Woods Hole only 1 to 2 months after spawning 

 commences there. One that was kept in an 

 aquarium there by Williams u grew from 10 mm. 

 to 22 mm. in length in 11 days; and Nichols and 

 Breder's 12 observation that fry of the year in 

 Sandy Hook Bay grew from an average length of 

 about %-inch (to the base of the tail fin) in May, 

 to about 2 to 2% inches by late September, is in line 

 wi thTracy 's statement 13 that the fry are 2 to 3 inches 

 long in July in Rhode Island waters, growing to 



• Zoologies, New York Zool. Soc., vol. 9, 1927, pp. 181-182. 



• Hlldebrand and Schroeder, Bull. U. S. Bur. Fish., vol. 43, Ft. 1, 1928, p. 

 172. 



>» Williams (Bull. Mus. Comp. Zool., vol. 40, 1902, No. 2) has given a brief 

 account of the anatomical changes that take place during the passage of the 

 eye in the sand flounder, and a more detailed account for the winter flounder. 

 For photographs of larvae and small fry, see Moore (Bull. Bingham Oceanogr. 

 Coll., vol. 11, art. 3, 1947, fig. 3). 



" Bull. Mus. Comp. Zool., vol. 40, 1902, p. 3. 



u Zoologies, New York Zool. Soc, vol. 9, 1927, pp. 181-182. 



>» Kept. 40, Comm. Inland Fish. Rhode Island, 1910, p. 166. 



4 inches and upwards in December. Fry only 

 1 to 2 inches long reported by Nichols and Breder 

 at Orient, N. Y., in December, seem to have been 

 from a late-hatched brood. 



Figure 152.— Larva, 5.5 mm. 



Figure 153. — Larva, 8 mm. 

 Sand flounder (Lophopsetta maculata). 



Moore concludes, from her very detailed study 

 of the growth zones on scales and otoliths, that 

 sand flounders in Long Island Sound average about 

 4K inches long when they are 2 years old (i. e., at 

 the beginning of their third summer); about 7% 

 inches at 3 years; about 9 to 10 inches at 4 years; 

 about 11 inches at 5 years; about 11 % inches at 

 6 years; and about 12 inches at 7 years. 14 And 

 Gulf of Maine fish probably grow at about this 

 same rate. They mature at 9 to 10 inches; i. e., 

 in the third or fourth year, according to the fore- 

 going schedule. 



General range. — Coastal waters of eastern North 

 America, from the Gulf of St. Lawrence to South 

 Carolina; most abundant west and south of Cape 

 Cod, north and east of which it is confined to 

 favorable localities. 



Occurrence in the Gulf of Maine. — This flounder 

 is not common in the Gulf of Maine, except 

 locally. Dr. W. C. Kendall found it at Monomoy; 

 we have caught one (p. 292) on the outer shore of 

 Cape Cod; Storer found it at Provincetown, where 

 he saw a considerable number in shoal water; it is 

 reported from North Truro; from Gloucester 



» Bull. Bingham Oceanogr. Coll., vol. 11, art. 3, 1947, pp. 47-61. 



