FISHES OF THE GULF OF MAINE 



29 



projecting far beyond the mouth, obliquely trun- 

 cate in front, terminating above in a sharp point, 

 and with the head strongly compressed sideways 

 abreast of the front of the mouth. This results in 

 so bizarre an appearance that the young basking 

 shark was thought at first to represent a separate 

 species. A gradual transition takes place from 

 the juvenile shape of head to the adult shape when 

 a length of 12 to 16 feet has been reached. We 

 need only note further that the triangular first 

 dorsal fin stands midway between pectorals and 

 pelvics; though not so high in proportion as that 

 of the mackerel-shark tribe, it rises high in the air 

 when a large basking shark lies awash on the sur- 

 face, as is their habit, a convenient field mark 

 (p. 29). 



Color. — Upper surface grayish brown, slaty 

 gray, or even almost black. The lower surface 

 has been described repeatedly as white. But the 

 Menemsha specimen described by Allen w was of a 

 somewhat lighter shade below than above, without 

 white markings, as was a Massachusetts Bay 

 specimen recently examined by us; while one 14 

 feet long captured at West Hampton, L. I., 

 on June 29, 1915 68 had the belly as dark as the 

 back, with a white patch underneath the snout in 

 front of the mouth. 



Size.- — The basking shark rivals, though it does 

 not equal, the whale shark of tropical seas in size. 

 Reports that an occasional basking shark may 

 reach a length of 50 feet probably aro not an 

 exaggeration, for the catch on the coast of Norway, 

 for the period 1884 to 1905, included one of about 

 45 feet and three of about 40 feet, with the six 

 next longest ranging between 36 feet and 30 feet 3 

 inches. The three longest for which we find 

 definite measurements for the western Atlantic 

 were of 32 feet 2 inches, 32 feet, and 30 feet 3 

 inches. But others up to 35 feet long have been 

 credibly reported as killed near Eastport, Maine, 

 many years ago; and one captured at Musquash 

 Harbor, New Brunswick, near the mouth of the 

 Bay of Fundy in 1851 was said to have been about 

 40 feet long. It is probable that they are at least 

 5 to 6 feet long when born, the three smallest so far 

 reported having been between 5 feet 5 inches and 

 about 8 feet 6 inches long. Matthews 69 concluded 

 from studies of basking sharks taken near the Isle 



of Skye that fish up to 10 feet are in their first 

 year, those of 15 feet in their second year. Males 

 mature sexually at about 18 to 20 feet as indicated 

 by the lengths of their claspers, females at about 20 

 to 23 feet; i. e., when 3 years old or perhaps 4, 

 according to Mathews' estimate. 



We find no exact weights for large basking 

 sharks from the Atlantic. But 6,580 pounds for 

 one of 28 feet, and 8,600 pounds for another of 30 

 feet, from Monterey, Calif., is doubtless a fair 

 indication of what a fairly large one may be 

 expected to weigh. Estimated weights for smaller 

 ones, from the Pacific, are about 6,600 pounds at 

 about 23 feet, 1,000 to 1,800 pounds at 13 to 15 

 feet, and 800 pounds at 8 feet 4 inches. 60 A young 

 one, 12 feet long, killed off Digby, Nova Scotia, 

 August 16, 1939, weighed 359 pounds, after it had 

 bled, 61 and one almost 20 feet long, taken off 

 Portland, Maine, in 1936, weighed 550 pounds, 

 dressed. 



Habits. — This is a sluggish, inoffensive fish, help- 

 less of attack so far as its minute teeth are con- 

 cerned. It spends much time sunning itself at 

 the surface of the water, often lying with its back 

 awash and dorsal fin high out of water, or on its 

 side, or even on its back sunning its belly; some- 

 times it loafs along with the snout out of water, 

 the mouth open, gathering its provender of plank- 

 ton. They pay so little attention to boats that 

 it is easy to approach one of them within harpoon 

 range, and excellent motion pictures have beea 

 taken of them in Irish waters. 62 But they have 

 also been seen jumping, perhaps to shake off para- 

 sites. Those seen in the Gulf of Maine are usually 

 traveling singly. But they are known to congre- 

 gate sometimes in loose schools which may include 

 as many as 60 to 100 in the peak years of abun- 

 dance for them in regions where they are more 

 numerous than in the Gulf of Maine. 63 It is 

 chiefly during the warm half of the year that 

 basking sharks are encountered off the northeast- 

 ern United States and in the northern part of their 

 range in the opposite side of the Atlantic. It is 

 likely that those that summer in the inshore parts 

 of the Gulf simply withdraw in the fall, to pass the 



" Bull. Boston Soc. Nat. Hist.. No. 24, March 1921, p. 5. 



» Described by nussakof, Copeia, No. 21, 1915, pp. 25-27. 



» Phllos. Trans. Roy. Soc. London, Ser. B., vol. 234, 1950, pp. 217-316. 



» For further details as to slics of basking sharks, see Bigelow and 

 Schroeder, Fishes, Western North Atlantic, Pt. 1, 1948, pp. 151-152. 



•' Referred to by McKcnzte, Proc. Nova Scotia Hist. Set., vol. 20, 1940, p. 42. 



81 Shown in the film "Men of Arran." 



« See Bigelow and Schroeder, Fishes Western North Atlantic, Pt. 1, 

 1948, pp. 153, 154, for details as to their centers of population and secular 

 fluctuations in abundance in north European waters. 



