70 U. S. BUREAU OF FISHERIES 
the carbohydrate and metal metabolism of the oyster. Since all the 
activities of an organism, in the final analysis, depend on respira- 
tion, the study of the gaseous exchange of the oyster was expected to 
throw light on other features of its metabolism. During the summer 
of 1939, experiments along this line were carried out at Woods Hoie 
by Dr. Galtsoff, with the assistance of George Mishtowt. The pur- 
pose of the experiments was to determine whether the increased iron 
content had any effect on the rate of respiration. Oysters, poor in 
iron, were kept in water with high iron content until a great deal 
of the metal had been assimilated in the animal tissues. The rates 
of oxygen consumption of these oysters before and at the end of the 
experiments were determined and compared. 
The excess of iron in the tissues seems to slightly increase the 
oxygen consumption, although the results of the summer’s experi- 
ments are complicated by the change in the organisms caused by 
spawning. There was a general decrease in the oxygen consump- 
tion after spawning which amounted to 22 percent in the control 
oysters, while in the “iron fed” oysters it averaged only 19.4 percent 
There was an apparently significant difference between the change of 
the metabolic rates of the male and female oysters, which is probably 
determined by their sex. In both sexes the lowest metabolic rate was 
found to oecur during the after-spawning period, which is character- 
ized by the poorest condition of the oyster meat. It is planned to 
continue this investigation by carying out tests during the various 
seasons of the year. : 
OYSTER PESTS AND PARASITES 
In addition to the starfish and oyster drill, which devour large num- 
bers of newly set oysters, two other molluscs, namely, Anomia and 
Crepidula, were found to be responsible for the mortality among spat 
in the Long Island area. Asa rule, the setting of Anonvia and Crepi- 
dula occur almost simultaneously with the setting of oysters. How- 
ever, because of the much lower rate of growth of oysters, Anoméa or 
Crepidula soon suffocate the spat by covering 1t with their shells. 
However, heavy mortality among oyster spat cannot be attributed 
soley to their enemies such as starfish, drills, Anomia and Crepidula. 
The oyster set died in some areas where these enemies were not numer- 
ous enough to inflict heavy losses. It is quite probable that in some 
areas of Long Island Sound the mortality of spat was due to a disease 
or infestation by some unknown parasite. 
Starfish setting —Vhe first setting of starfish in 1939 took place in 
Long Island Sound between July 13 and 17, and continued until Sep- 
tember 11 with two distinct peaks in the intensity, the first between 
July 20 and 24, and the second between July 31 and August 3. The 
heaviest setting took place at the stations located at 30- and 40-foot 
depths. The numbers of starfish that set in 1939 were small, and even 
at the height of setting the young starfish rarely averaged two per shell. 
However, because of a very high rate of survival among recently set 
starfish, and because of their rapid growth, they soon became a serious 
menace. : 
Distribution of starfish—In accordance with the practice established 
last year, semiannual surveys of the distribution of adult starfish in 
Long Island Sound were made in March and November. As compared 
