Fishes of the Western North Atlantic 387 



gray in the fresh-caught specimens we have seen, but also described as dirty gray, or very 

 pale, perhaps as a result of living over a white sand bottom; lower parts white; lower sur- 

 faces of pectorals grayish and sooty toward tips; pelvics and anal grayish white. 



Size. The fact that embryos up to 965 mm. have been reported, as well as a free- 

 living specimen hardly larger (see Study Material, p. 382), suggests that this is about the 

 usual size at birth. Although it is generally recognized that this is a considerably larger 

 shark than milberti, the only exact length records of large adult specimens, identified be- 

 yond question as this species, are nine females from southern Florida that ranged from lO 

 feet 4 inches to 1 1 feet 8 inches'" and one specimen from Georges Bank 1 1 feet long."* 

 It is reputed to reach 14 feet, although perhaps not from any exact evidence. 



Developnental Stages. Embryos have not been described; ten have been recorded in 

 one Florida female and embryos up to 965 mm. long in another. 



Habits. Although obscurus has been known to science since 1818 and is common 

 enough to be caught occasionally close to Woods Hole and reputedly more often near 

 New York, our only information regarding its diet is that it is a fish-eater; off the east 

 coast of Florida portions of other sharks have been found in its stomach as well as various 

 reef fishes, such as groupers, lizardfish {T rachinocefhalus) , flatfishes {Citharichthys)^ 

 red goatfish {Mullus) and cusk eels (Ophidian). The wide distribution of the locali- 

 ties where positively identified specimens of obscurus have been taken show it to be much 

 more pelagic in habit than are either milberti (p. 372) or leucas (p. 341). On the other 

 hand, the record of captures proves that it comes closer inshore, even into very shoal water, 

 than does longimanus (p. 359). All captures in the northern part of its range have been 

 for the warm months, whereas it is present the year round along eastern Florida but only 

 in the winter off southwestern Florida, which is evidence that some obscurus migrate north- 

 ward along the United States coast in spring or early summer, as do various other warm- 

 water sharks. 



All that is definitely known of its breeding habits, beyond what is stated above, is that 

 adult females containing embryos of 575 to 965 mm. are reliably reported off southwestern 

 Florida, and that free-living specimens, so small that they had evidently been born only 

 shortly previous, have been taken off southeastern Florida in late winter,"* and off Louisi- 

 ana and near Woods Hole in August (see Study Material, p. 382). It seems, therefore, 

 that obscurus may produce young anywhere within its geographic range and over a long 

 season. 



Relation to Man. Obscurus is not taken in large enough numbers to be of any commer- 

 cial importance anywhere, although such as are caught in the shark fishery in southern 

 Florida or in the West Indian region are utilized for leather, etc., as in the case of other 

 large sharks."" 



117. Springer, Proc. Fla. Acad. Sci., 5, 1939: 25. 



118. Firth, Bull. Boston Soc nat. Hist., 61, 1931 : 9; Bigelow and Schroeder, Bull. U.S. Bur. Fish., 48, 1936: 321. 



119. Personal communication from Stewart Springer. 



120. It seems more likely from the context that a recent account of the actions of a Dusky Shark, when hooked on 

 rod and reel (Wise, Tigers of the Sea, 1937: 262), may have referred to milberti. 



