chapter 10 



Selachians 

 Extraordinary 



Along the shore of every maritime state 

 in the United States and every coastal 

 province in Canada; within and beyond the territorial waters of every 

 nation that boasts a shore; around every island lapped by the sea; in the 

 abyss and in the shoals of every ocean, cold or warm, on earth— and even 

 in lakes and in rivers hundreds of miles from the sea— there are Sela- 

 chians. Some are known as sharks, some as rays, some as skates; some 

 are curious links between. 



Their diversification is wondrous, for, while developing into innumer- 

 able species, the Selachians have managed to weave strong threads of 

 similarity into their family tapestry. Often these threads are impercepti- 

 ble to the untrained eye. But they are there. The Great White shark 

 {Carcharodon carcharias) is a swift, graceful, and pelagic fish that roams 

 the oceans with the arrogance of an invincible corsair. The "Sleeper" 

 or Greenland shark (Somniosus rmcrocephaliis) spends much of its life 

 languishing on the bottom of polar seas. A skate may be a small, inert, 

 disk-shaped creature buried in the sand in shallow water. A ray may be 

 a giant, diamond-shaped beast that leaps out of the sea. They are all 

 Selachians. 



How many Selachian species there are, no one truly knows. Within 

 the past century, not one important ichthyological expedition in tem- 

 perate or tropical seas has returned without reporting the discovery of 

 new and therefore uncatalogued species. Some of these were later re- 

 classified as more or less identical to previously reported species, but the 

 rest were truly new discoveries. In their encyclopedic study of the 

 shark, Fishes of the Western North Atlafitic,^ Henry B. Bigelow and 

 William C. Schroeder reported in 1948 that 225 to 250 species of shark 

 were known in the world, and 300 to 340 species of skates, rays, and their 

 alhes had been described. Ten years later, at a conference on sharks 

 attended by shark experts from the United States, Australia, Japan, 



1 Memoir Sears Foundation for Marine Research, No. 1, Fishes of the Western 

 North Atlantic, Part One (New Haven, 1948). 



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