62 PEARLS AND PEARLING 



Raccoons are very destructive in some localities. They 

 seem to prefer the small mussels, although they also bring 

 out some of the large ones and if they cannot open them 

 they leave them to die in the sun and possibly they may 

 eat them later if they happen to find them again. Other 

 predacious animals that have been known to destroy the 

 mussels for food are the mink, otter and bear. 



Snakes also kill some of the smallest mussels. The 

 author remembers an experience in Iowa when he saw a 

 snake try to kill a large mussel. The water was shallow 

 on the rocks so it was easy for the snake to find the 

 mussel. The reptile bit into the body of the mussel while 

 the shells were opened and immediately the mussel closed 

 its shells. It was a very strange battle. The snake 

 writhed and twisted about blindly, often letting the mus- 

 sel fall upon the rocks, while the mussel held tightly to 

 its enemy. Soon they disappeared into deep water and 

 the result of the battle is not known. It is probable, 

 however, that both lost their lives in the strange battle. 



Catfish, crawfish, and mud turtles are also said to de- 

 stroy mussels, but the extent of their damage is never 

 known. 



Cattle and horses often trample Over beds in shallow 

 water and kill large numbers cvf mussels. Aquatic birds 

 kill and devour many of the smallest mussels and those 

 having very thin shells. It has also been said that leeches 

 and other parasites injure mussels, especially when these 

 parasites are very numerous. 



There are some physical causes of destruction that are 

 very disastrous. 



