MARINE ANIMALS THAT STING 



55 



The species within these families are too numerous to list indi- 

 vidually, so only a few representative species, which have been 

 studied to a considerable extent by the venomologist, will be in- 

 cluded. However, there are a few generalities which are pertinent 

 to the group as a whole. 



Fig. 27. Map showing the geographical distribution of stingrays. Although 



plagic and deep-water species are known to exist, stingrays are primarily 



shallow-water inhabitants, along coastal areas. 



Rays are common inhabitants of tropical, subtropical, and warm 

 temperate seas (Fig. 27). With the exception of the family Pota- 

 motrygonidae, which is confined to freshwater, rays are essentially 

 marine forms, some of which may enter brackish, or freshwaters, 

 freely. Rays are swimmers of moderate depths, and are most com- 

 mon in shallow water. A deep sea species has recently been reported 

 from the Central Pacific Ocean. Sheltered bays, shoal lagoons, 

 river mouths, and sandy areas between patch reefs are favorite 

 habitats of rays. They may be observed lying on top of the sand, 

 or partially submerged, with only their eyes, spiracles, and a por- 

 tion of the tail exposed. Rays burrow into the sand and mud, and 

 excavate the bottom with the use of their pectoral fins, by which 

 means they obtain the worms, molluscs, and crustaceans upon which 

 they feed. 



Representative Stingray Species: 



Stingrays or Whiprays - Dasyatidae 

 Diamond Stingray, Dasyatis dipterurus (Jordan and Gilbert) 

 (Fig. 28, Top). Occurs from British Columbia to Central America. 



