122 U.S. BUREAU OF FISHERIES 



larvae were found in the flesh of 55 percent of the perch and 94 per- 

 cent of the rock bass of Muskelkmge Lake and in 89 percent of the 

 perch and 100 percent of the rock bass from Nebish Lake. Intestinal 

 trematodes were found in 79 percent of the rock bass of Muskellunge 

 Lake and in 62 percent of those from Trout Lake; only 10 percent 

 of those from Nebish Lake were infested with these parasites. Nem- 

 atodes, cestodes, and Acanthocephala were present in many of the 

 fish also, but usually not in such a large percentage of them. 



OYSTER INVESTIGATIONS 



Under the direction of Dr. P. S. Galtsoff, investigations concerning 

 various problems of the oyster industry were carried out in New 

 England and the North Atlantic States (Vineyard Sound, Buzzards 

 Bay, and Long Island Sound) ; South Atlantic States (Beaufort, N.C., 

 South Carolina, Georgia, and west coast of Florida) ; and on the 

 Pacific coast in Washington and California. The selection of spe- 

 cific projects of study in different sections of the country was governed 

 both by the local conditions and most urgent needs of the industry. 

 Thus, in New England and the North Atlantic States, where previous 

 work of the Bureau materially helped in the solution of the problem 

 of propagation of the oyster, the main efforts were directed to a study 

 of the methods of growing, fattening, and improvements of the 

 nutritive quality of the oysters. On the other hand, in the South 

 Atlantic States where the depleted state of the natural oyster reefs 

 threatens the existence of the industry, principal attention was given 

 to the methods of restocking and maintaining the productivity of the 

 bottoms. On the Pacific coast the work consisted in studies of the 

 cultivation and development of the native Olympia oyster. 



INVESTIGATIONS IN NORTH ATLANTIC STATES 



In cooperation with the Shellfish Commission of the State of 

 Connecticut the Bureau has established a field laboratory on State 

 property at Milford, Conn., and planted several thousand bushels of 

 3-year-old oysters on a 6-acre tract of bottoms in Long Island Sound 

 set aside for that purpose by the Shellfish Commission. Oysters for 

 planting were donated by the Mansfield Co. The authorities of Yale 

 University cooperated in this project by granting to the Bureau's 

 investigator the privilege of using the laboratory facilities of the uni- 

 versity. Boats for tliis work were furnished by the State Shellfish 

 Commission and by the Connecticut Oyster Farms Co. 



Since April 1932, field observations at Milford and vicinity have 

 been carried out by V. L. Loosanoff and Dr. P. S. Galtsoff. The 

 results obtained during the 9-montli period show that oyster meats 

 undergo important chemical changes. During the early summer the 

 glycogen content gradually decreases reaching a minimum just before 

 spawning. The discharge of eggs and sperm is followed by a consid- 

 erable loss of solids and corresponding increase in the water content 

 of the meat. During this period, which lasts about 2 weeks, the 

 water content increases from about 75 percent to over 90 percent. 

 It is obvious that during this period the food value of the oysters is 

 very low. The period of spawning is followed by a period of rapid 

 accumulation of glycogen which before the onset of cold weather 



