Selachians Extraordinary 271 



Tailed) Sting ray {Dasyatis dipteniriis Jordan and Gilber, 1880), which 

 ranges from British Columbia to Central America. It grows to 6 feet 

 or more. In a U.S. National A4useum report, S. F. Hildebrand said of 

 Sting ravs of this type and size: "These rays are considered very dan- 

 gerous by the fishermen, and cases are on record where they have 

 caused severe injury, if not death, to persons hit by the stings." 



Family G}'W7Z2/nJ^^— Butterfly Rays 



Flapping its wide pectorals like wings as it courses upward from 

 its normal haunts at sea bottom, the Butterfly ray has the look of grace 

 and beauty that inspires its name. Its body is unusually colorful for a 

 ray. Gray, brown, purple, or green markings lace its back like filigree. 

 On the bottom, its colors change, darkening on a black background, 

 paling on a light background. And there, on the bottom, prowling 

 for food, sluggishly moving with the tides, it colors muted, the Butter- 

 fly ray is as dull to behold as a butterfly still locked in its cocoon. 



The Lesser Butterfly ray {Gymnura micrura Bloch and Schneider, 

 1801), is known in coastal waters from Brazil to Maryland and occa- 

 sionally is found as far north as southern New England. Off Galveston, 

 Texas, and in the lower parts of Chesapeake Bay (where it is known under 

 the misnomer of Sand skate), it is fairly abundant. 



A Pacific Coast version {Gymnura marmorata Cooper, 1863) is 

 called the Butterfly Sting ray because at the end of its diminutive tail 

 there is a sting. G. micrura doesn't have a barb, but its rarer, larger 

 Atlantic Coast relative, the Giant Butterfly ray {GyiJinura altavela Lin- 

 naeus, 1758) has one or more. The Lesser Butterfly ray grows to a 

 breadth of 3 to 4 feet; the Giant is believed to attain a breadth of more 

 than 1 2 feet; the Butterfly Sting ray at maturity is 4 to 5 feet wide. 



The family includes two genera: the Gy?miura, whose species, found 

 in the Red Sea, the Atlantic, the Pacific, and the Mediterranean, have 

 no dorsal fins on their tail, and the Aetoplatea, whose species are 

 found off South Africa, in the Red Sea, the Indian Ocean, and the East 

 Indies, and have small dorsal fins. Another example of the curious ways 

 in which Selachians develop minor, enigmatic differences. 



Family Urolophidae—KovND Sting Rays 



These Sting rays differ from the Dasyatidae in two basic ways: they 

 are smaller (usually 30 inches long at most), and they have short, stout, 

 and rather muscular tails. Sometimes they are classed with the Dasya- 

 tidae. 



The Pacific Round Sting ray mentioned earlier in the description of 

 venom (Urolophus halleri) is, strictly speaking, a member of this family. 

 U. Halleri, the commonest California Sting ray, is found from Monterey 



