64 
BULLETIN OF THE BUREAU OF FISHERIES 
PERIOD OF ACTIVITY 
The length of the period of activity of diamond-back terrapins, of course, varies 
from year to year according to temperatures. At Beaufort some of the animals 
begin to move about on warm days in March, but generally they do not become 
active and take food until about the latter part of April or early in May, and the 
period of activity may be said to end again sometime during October or, rarely, as 
late as early in November. They feed regularly only from about the latter part of 
May until early in October. On cool days they cease to feed and even mild days in 
midsummer cut down their capacity for food. 
FOOD, FEEDING, AND COST OF FOOD 
The food of terrapins in nature is reported to consist of small mollusks and crus- 
taceans. In captivity, as already indicated, they readily take fish cut in pieces of 
suitable size, crabs, shucked oysters, and clams. At Beaufort, however, fish and 
some blue crabs chiefly are fed. Fiddler crabs enter the pens, and some small 
mollusks, too, are available. The animals appear to thrive on these foods. 
The fish used during the summer are purchased directly from commercial fisher- 
men, and they generally consist of menhaden and other unsalable fish or of small 
food fishes that would bring little on the market. Frequently quite a few blue crabs 
are included with the “scrap” fish. During the winter months, when only about 
1 ]/ 2 pounds of food a day is used, small and cheap grades of fish are purchased from 
local fish dealers; or when oysters were fed they either were collected by the terrapin 
culturist or purchased in the shell and opened at the laboratory. 
During 1927 the fish and crabs delivered by the fishermen were purchased at 2 
cents per pound. During the winter, when the fish were bought from dealers, the 
price ranged from 6 to 7 % cents per pound. The total cost of food for the calendar 
year 1927 was $236.52. With this amount, about 2,936 recently hatched young 
terrapins were fed during the winter and 3,707 animals of various ages (mostly adults) 
were fed during the summer. The cost of food for the young winter-fed animals for 
a seven-months period was 7% mills per head. The cost for all the animals held in 
outdoor pens for the year 1927 averaged nearly 6 cents per head. It is evident, 
therefore, that the cost of food at Beaufort is not great. 
For the small terrapins, a year or less of age, the fish are scaled, the large bones 
are removed, and then they are put through a food chopper. For larger terrapins, 
the fish and crabs together, as received from the fishermen, are put through a feed 
cutter of the type used by farmers, which cuts the food into pieces small enough to 
be managed by the terrapins. The food is thrown on the ground in a clean, solid 
place near the edge of the water. The animals emerge, take a piece of food, and 
generally return to the water to eat it. Care is exercised to supply sufficient food 
and not too much. Food placed on the ground at the edge of the water can be 
removed readily if it is not all consumed, for it is highly essential to prevent putre- 
faction, and less is wasted by the animals than if it were thrown into the water. 
