16 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



the mackerel shark {Lamna nasus), and the blue All Gulf of Maine sharks give birth to young 

 shark (Prionace glauca), occur with us in numbers that are not only practically adult in structure 

 sufficient for one to be fairly sure of seeing them but of relatively large size at birth, and there is a 

 during a summer's boating off the coast north of placental connection between mother and embryo 

 Cape Cod. in some, but not in others. Still other sharks lay 

 With the larger sharks generally so scarce (the eggs; this is true of the chain dogfish (Scyliorhinus 

 mackerel shark is harmless to anything larger than retifer, p. 34), which is common out on the conti- 

 the fishes on which it feeds, and the blue nental shelf from the offing of Cape Cod, south- 

 shark is also harmless, although better armed), ward, and of its immediate relatives; also of the 

 the danger of attacks on bathers is negligible in heterodontids or Port Jackson sharks which are 

 our Gulf. Indeed, not a single well-authenticated not represented in the Atlantic, 

 instance of the sort is on record 27 for the past There is so little market for sharks in Gulf of 

 80 years for the coast north of Cape Cod, though Maine ports (attempts to introduce the dogfish as 

 the beaches are crowded every summer with a food fisn having failed so far) that the amounts 

 vacationists. But as long as the white shark or landed in Maine and Massachusetts were only 

 man-eater (Carcharodon carckarias) does stray aD0U t 240,000 pounds in 1947, and about 309,500 

 occasionally into the Gulf (p. 26), it is always poimds in 1949; they interest fishermen chiefly as 

 remotely possible that we may be horrified some nuisances because of the damage they do to nets 

 summer by the news of tragedies such as occurred a nd other gear, except that mackerel sharks are 

 on the New Jersey coast in July 1916, when marketable. 



several persons were killed or injured, presumably Jfc ig posgible tQ y^ a]1 ^ gharks SQ faf 



by a small shark of this species that was captured kiwn from ^ Qulf (and ^ indudes aU fchftt 



nearby a few days later,- 8 and near Mattapoisett, are likdy tQ Qcmr there fc g) by the 



on Buzzards Bay, Mass., on July 25 1936, when gizes ^ rektive locations of the ^ and by 



a swimmer was fatally mimed by a shark, species , , ,, , , , , ,_ 



. „ J ' * such tooth characters as mav be seen at a glance 

 not determined. ,, ., -, ' t ,, • ,, ,, c 

 at the open mouth or easily felt with the linger 



« In 1830 (an event often quoted) one Joseph Blaney, fishing from a small (qfter the shirk is dead') 



boat in Massachusetts Bay off Swampscott, Mass., was attacked by some ^ "■'" 



fish that was seen to overset and sink his boat and, presumably, devoured Wq have attempted ill the following descriptions 



him, for neighboring fishermen who hastened to his rescue found no trace of . _ . _ . 



him. Whether his attacker was a large shark or a killer whale is an open of the Several Species to include Ollly SUCh features 



question. „,,.,„,„ „„ „ , , ,„,„ x - as will tell what shark is at hand; for more minute 



"Murphy and Nichols (Brooklyn Mus. Quart., vol. 3, 191fi, No. 4, pp. 



t45-if;o) give a detailed account of this occurrence. particulars we refer the reader to our account of 



« See Gudger (Amer. Midland Natural., vol. 44, 1950, p. 714) for clinical . . , . , » T , , . . , , 



details of this case. tue sharks of the western North Atlantic (p. 2). 



Key to Gulf of Maine Sharks 



1 . There is an anal fin 2 



There is no anal fin 16 



2. Head greatly expanded sidewise, at level of eyes, in hammer- or shovel-form 3 



Head of ordinary shape, with rounded or pointed snout 4 



3. Outline of front of head only slightly concave opposite nostrils if at all so; grooves (if any) from nostrils shorter than 



horizontal diameter of eyes; free tip of second dorsal fin is not longer than forward margin of the fin; rear margin 

 of anal fin is only weakly concave; teeth near outer corners of mouth are rounded, without sharp cusps. 



Shovel head, p. 44 



Outline of front of head is deeply indented opposite each nostril; grooves from nostrils are more than twice as long as 



horizontal diameter of eye; free tip of second dorsal fin is considerably longer than front margin of the fin; rear 



margin of anal fin deeply concave; teeth near corners of mouth are like those near center of mouth, with sharp 



eusps Hammerhead, p. 45 



4. Caudal peduncle (root of tail) is not widely expanded sidewise as a lateral keel on either side; upper lobe of caudal 



fin is much longer than lower lobe 8 



Caudal peduncle is widely expanded sidewise as a lateral keel on either side; lower lobe of caudal fin is nearly as long 

 as upper lobe, suggesting the caudal fin of a mackerel or swordfish 5 



