40 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
66 cm. were males. The sexes can be detected by the following constant secondary 
sexual characters: The head in the female from above appears triangular, in the male 
the snout is distinctly blunter. In the 
female the snout is rounded in transec- 
tion, in the male the surfaces of the 
snout are flat. 1 During December, Jan- 
uary, and February Cunningham col- 
lected 8 male congers. The largest 
female conger ceased to feed in March. 
On July 24 a few eggs were obtained by 
squeezing. These contained no oil- 
spheres and sank in water with a density 
of 1.027. The diameter of one after the 
formation of the perivitelline space was 
1.6 mm. This female died on Septem- 
ber 10. Her ovaries weighed 7 pounds 
5 ounces. The “ovaries increase very 
much in size and weight during the fast- 
ing period at the expense of the rest of 
the body, while in the total weight of 
the fish a great reduction takes place. 
Each conger eel breeds only once in a 
lifetime.” He calculated the eggs in another female to be 7,925,280. Out of a total 
number of 34 congers 11 were males and 23 were females. That no ripe congers are 
caught is because they do not feed for weeks before becoming ripe. 
Fig. 1. — Outline of embryo, showing position in membrane and 
shape of the yolk. August 1. 
Fig. 2. — Outline of enlarged part of the 
yolk and yolk-sac of an embryo of 
the same age as fig. 1 , from below. 
Fig. 3. — Embryo freed from its membrane, showing beginning 
of the constriction of yolk at its anterior end. August 1. 
The eggs secured by Dr. Sargent measure 2.4 to 2.75 mm. from membrane to 
membrane. 2 The yolk, as in the eggs described by Raflaele, is made up of trans- 
1 In Nineteenth Report of the Commission of Fisheries of New York, page 280, Bean describes 5 male eels. It is very 
probable from Grassi’s observations that these were the males of the common eel in their nuptial dress. 
2 Among other eggs collected by Dr. Sargent and preserved in formalin were six with many of the characters of eel 
eggs. They were large, with a very large perivitelline space, the yolk in spheres and with one large and a number of 
smaller oil-spheres. These eggs were notably larger than those brought home alive. They measure 3 mm. from membrane 
to membrane; the yolk measures 1.75 mm, or a little more. It is possible that these are identical with those to be described. 
The germ lies at one side of the egg, the oil-sphere at the other. 
