THE AMERICAN LOBSTER. 
73 
It should be borne in mind that, as we have already seen, a certain number of 
lobsters from 9 to 12 inches long have never borne eggs. Thus the chances for error 
in making estimates of this kind are further increased. 
The percentages given in table 21 must therefore be greatly increased to express 
the ratio between the actual spawners of the current year and those which have 
reached the spawning age, since in the total number of females there were undoubtedly 
included many which were not mature. While the percentage of egg lobsters taken 
in the same locality may vary considerably from year to year or from mont h to month 
it seems probable that if we could average the results taken from many different 
localities along the coast we should find that the number of spawners each year 
represents about half the total number of mature females. 
RELATIVE ABUNDANCE OF THE SEXES. 
Some species of Crustacea are strictly monogamous, such as the beautiful tropical 
shrimp, Stenopus hispidus , which is always seen swimming in pairs, the male and 
female being rarely separated. This is also true of another delicate shrimp, Pontonia 
domestica, which lives in the mantle chamber of the mollnsk Pinna. In such cases the 
sexes are of necessity about equally divided. But in the lobster there seems to be 
no attachment of this kind. It is probable that a given male fecundates more than 
one female, and it is certain that the sexes are distributed with great irregularity, at 
certain seasons of the year at least, as I shall presently show. Nevertheless, if an 
extended census could be taken, at different points on the coast, it is very probable 
that but little difference would be found in the numbers of the sexes. 
The following table shows the relative abundance of male and female lobsters 
found in Woods Hole Harbor and at No Man’s Land: 
Table 22 . — Relative abundance of male and female lobsters at Woods Hole and Ho Man’s Land 
Date. 
Total 
catch . 
Male. 
Female. 
Per cent 
of females 
to males. 
Woods Mole: 
1880. April 24-30 
104 
49 
55 
112.2 
May 
942 
440 
502 
114.3 
-I une 
2. 184 
1,009 
1, 175 
116.6 
1893. December 
224 
123 
101 
82. 1 
1894 January 
501 
250 
251 
100. 4 
February 
240 
116 
130 
112.07 
March 
348 
161 
187 
116. 15 
April 
457 
247 
210 
85.02 
May 
434 
197 
237 
120. 30 
June 
447 
219 
228 
104. 11 
Totals 
5, 887 
2, 811 
3,076 
106. 30 
No Man’s Laud : 
1894. May 
1,318 
84 
1,234 
r, 409 
In the monthly catches at Woods Hole in 1889 the females preponderated by 12 to 
1G per cent, while in the total catch for 1893-1891 the sexes are very nearly evenly 
divided. During this period the percentage of females to males fluctuated from 82.1 
minus to 120.30 plus, a variation of about 38 per cent. The traps were stationary, 
but the lobsters were constantly moving about over the bottom; yet there was no 
segregation of the sexes, and such variation as we find in the monthly catches has no 
special significance. 
