120 BULLETIN OF THE BUREAU OF FISHERIES. 
NUMBER OF BATCHES OF EGGS LAID. 
The prevailing supposition among most crabbers is that the female crab lays but 
one batch of eggs and dies shortly thereafter. Binford,* however, in 1911, reported 
that he observed the eggs hatch from a sponge on a female crab, which he then dis- 
sected. The ovaries were examined and found to contain “nearly mature eggs, as was 
judged from their size and color.” He concluded from this fact that the crab would 
have been capable of spawning again. Hay and Shore,? 1918, state that it is believed 
that the female crab molts but once, “‘although she may produce more than one lot of 
eggs.” The following experiments and observations were made in an endeavor to test 
this matter more fully. 
Two crates, measuring 2 by 2 by 4 feet, were constructed from chicken wire fenc- 
ing. About 30 female crabs, which were known to have spawned, were confined in 
each crate during September, 1916 (PI. LIV, fig. 36). The crates were partially sunk in 
the mud and water to a depth of about 6 feet at low tide. The crabs were fed two 
or three times a week with bits of fish which were pushed by a stiff wire down a gal- 
vanized-iron sheeting tube into the crates. Feeding was discontinued about December 
I, asit was found from other experiments that the temperature of the water was below 
50° F. and that crabs eat little or nothing at such low temperatures. It was hoped that 
some of the crabs might survive until the following spring, when the question of spawn- 
ing could be tested. The effort was a failure, however, for it was found on lifting the 
crates in the spring that the crabs were all dead. 
Effort was also made to keep some adult female crabs through the winter in the 
United States Fisheries biological laboratory at Beaufort, N. C. Although two crabs 
survived until the following June, and were placed in floats, neither spawned. Judg- 
ing from their appearance at the time when placed in the floats, they were not in a very 
vigorous or healthy condition. 
During the winter of 1916-17 a method was found by which this problem was 
successfully met and it was shown that at least a second batch of eggs may be laid by 
the female crab. The procedure followed and the results attained are here discussed. 
It was found that it was possible to determine, in the case of many of the female 
crabs which were examined during that winter and the subsequent spring, whether 
they had ever produced a sponge. Microscopic examination of the hairs on the 
swimmerets of these females revealed, in many cases, occasional hairs which still 
bore the tendrils that had served to hold the eggs of a sponge produced at some previous 
time, most probably the season immediately preceding. Often, the fragments of the 
shells which had incased the eggs were yet attached to the tendrils. Plate XLVIII, 
figure 10, represents a hair from the swimmerets of such a crab. Numerous tendrils 
and shells are to be seen still adhering to it. 
The method of examination was as follows: A cursory examination with the un- 
aided eye or a hand lens was first made. After some experience had been gained, 
it was found that remnants of a sponge were not found in case the swimmerets were 
bright and clean in appearance. In case they were blackened or débris of any sort 
was apparent, a small portion of the tips of the hairs on the anterior swimmerets was 
@ Binford, op. cit., p. 1. 
+ Hay, W. P. and Shore, C. A.: The Decapod Crustaceans of Beaufort, N..C., and the Surrounding Region. Bulletin, 
U.S. Bureau of Fisheries for rors-16, Vol. XX XV, Pp. 433. Washington, 1918. 
