38 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



an epidemic disease that cannot be referred to the heat. Some 

 small experimental beds at Wickford were completely destroyed in 

 this way, the clams dying, all nearly at the same time, and rotting 

 in their burrows. The subject of clam diseases has yet to be in- 

 vestigated. 



On one occasion, at least, the presence of the red-water in great 

 quantity seems to have been the direct cause of the destruction 

 of vast quantities of clams. About the first of October, thou- 

 sands of bushels of clams about an inch in length were washed ashore 

 on the beach about an eighth of a mile north of the Rhode Island 

 Yacht Club, at Pawtuxet, and when they were examined a con- 

 siderable portion of them were still alive. There had been, of course, 

 no excessive heat, and no storm of sufficient violence, in our opinion, 

 to wash the clams out of their burrows; but there had been, re- 

 cently, a phenomenal quantity of peridinium in that vicinity, and we 

 are strongly inclined to believe that the latter were the cause of 

 this wholesale destruction. It is, indeed, characteristic of most 

 animals, shrimp, crabs, flatfish, etc., in the presence of this plague, 

 to endeavor to come to the surface, and when they are first washed 

 ashore they are, as a rule, still alive. 



NATURAL ENEMIES OF THE CLAM. 



Clams are beset, from the very beginning, by numerous enemies. 

 The eggs and free-swimming fry furnish food for many varieties of 

 fish, mollusks, crilstacea, etc. As soon as they cease swimming and 

 commence to burrow, the young star-fish, mummychogs, crabs, 

 and "oyster drills" feed upon them. 



It is the universal verdict of fishermen that the paddler crab 

 (Callinectes hastatus) is a most serious menace to the young clams; 

 and, though experiments have been tried with this species, which 

 have given only a negative result, the rock crabs (Cayicer irroratus) 

 were found to dig up and eat clams of considerable size. In one of 

 our experiments four of these crabs dug up and made way Avith 

 twenty-one fair sized clams in the course of two weeks. 



