The Sharks— Part Two 353 



waters bv several species, including the peculiar Prickly dogfish (Oxy- 

 notus bnmiejisis Ogilby, 1893). Relatively rare, the Prickly dogfish is 

 instantly identified by its odd shape— its first dorsal sweeps upward like a 

 sail— and its extremely rough skin. It grows to about 2 feet. A common 

 Australian dogfish, called the Piked dogfish or Skittle-dog {Squalus 

 megalops Alacleay, 1881), is often filleted and sold as a food fish. It usu- 

 ally grows to about 2 feet. 



In the dark unknown of the deepest seas, many types of tiny sharks 

 live like fabled dwarfs. We see hardly more than fleeting glances of 

 many of them. Their lives in the nether world of the deep are cloaked 

 in eternal shadow. Some of them bear that ghostly glow that marks 

 many creatures of the abyss— luminescence. Others are as dark as the 

 gloom that shrouds them. But all that have been seen have the classic, 

 graceful lines of the typical shark. 



Some of them are members of the family Squalidae; others are 

 classified with the Dalatiidae, the Spineless dogfishes. Squalidae found 

 in the depths include: 



Squalus jernandinus Molina, 1782— This shark is so rare— and so 

 small— that one of the few known specimens in the western Atlantic 

 was fortuitously found in the stomach of an albatross caught off Ar- 

 gentina. The shark was not quite H^-o inches long. It is known to inhabit 

 the polar regions and the cool-temperature latitudes of the southern 

 hemisphere. 



Etmopterus hillianus Poey, 1861— About iVo inches long at birth, it 

 is known to grow to about 12^4 inches. It is found in the West Indies, 

 and from southern Florida to the mouth of Chesapeake Bay. It is some- 

 times called the Black-Bellied dogfish. One female was caught bearing 

 four young 3 Yo inches long. 



E. hillianus may be luminous, as are some other Etmopterus sharks, 

 including one known as the Lantern shark in South Africa because of 

 its luminous belly, and another, known only in the northern parts of 

 the Gulf of A4exico. The latter, E. vire?7s, is a pretty little shark with a 

 brown body striped with pale bluish gray and marked on the belly with 

 bright green iridescence. E. virens is believed to grow to no more than 

 about 1 1 ^ inches. In fact, a 9-inch female of this tiny species was found 



A tiny shark ( Etmopterus hillianus ) measuring only 1 foot in length when full-grown 



Courtesy, Harvard Museum of Comparative Zoology 



