188 
BULLETIN OF THE BUREAU OF FISHERIES 
Fig. 102. — Menidia menidia, egg, two-cell 
upper part of sides and back with numerous brownish dots; fins plain translucent; peritoneum 
black. 
Many specimens, ranging from very small (8 millimeters) to 130 millimeters (5J^ inches) in 
length, are at hand. Two subspecies are recognized from Chesapeake Bay by Kendall (1902, pp. 
282 to 267). We, too, find these forms, the extremes of which differ quite markedly. Inter- 
mediate specimens, however, are at hand, and the two varieties (subspecies) intergrade perfectly. 
In general, the subspecies notata, which is greatly in the minor- 
ity in the collection at hand, has a more slender body, rather 
more numerous scales in a lateral series, with a more forward 
position of the dorsal fins. The intergradations, however, are 
complete, and there are numerous specimens at hand that can 
not be said to belong to either typical form. Furthermore, the 
extremes as well as intermediates sometimes occur in a single 
lot collected in one locality within a few hours. 
This species is recognized by the rather large size, long anal 
fin, rather small scales, and the black peritoneum. It is shown 
under M. beryllina that there is a slight overlapping with respect 
to the number of anal rays. In the present species, in 68 speci- 
mens, the following results were obtained: One specimen had 20 
rays, 4 had 21, 7 had 22, 19 had 23, 17 had 24, 17 had 25, and 3 
had 26 rays. 
The food of this fish, according to the contents of 27 stom- 
achs, consists largely of small crustaceans. Other foods are 
worms, insects, minute ova of unknown origin, and algse. 
Spawning takes place from early spring to late summer. 
The largest number of ripe fish, however, were taken in April 
and May. In 1894, Kendall (unpublished notes) stated that many ripe fish were seined from 
March 15 to 20 in the vicinity of Hampton and Cape Charles, Va. The eggs (Hildebrand, 1922, 
p. 114) are deposited in shallow water, in “grassy” areas, where the fish collect in large schools. 
The eggs are provided with numerous gelatinous threads of considerable length, by means of 
which they become attached to vegetation and other objects in the water. In this species, as in 
M. beryllina, eggs of several sizes are present in 
the ovary at one time, and when one size is ripe 
and spawned the next is already large enough to 
be seen clearly with the unaided eye. The pro- 
tracted spawning season, together with the fact 
noted relative to the various sizes of eggs in the 
ovary, suggests that the fish may spawn more 
than once during a season. The eggs are spher- 
ical in form, about 1.25 millimeters in diameter, 
and slightly heavier than sea water. The period 
of incubation was about 16 days in water vary- 
ing in temperature from 40° to 60° F. The 
newly hatched larvae are about 5 millimeters in 
length and highly transparent, only a few yellow- 
ish green pigment spots being present. The fish 
assumes virtually all the characters of the adult 
when it has reached a length of 13 millimeters, 
and it is then readily recognized. 
This is the commonest and most abundant 
of the silversides, being found in all parts of the bay in both salt and brackish water. It is more 
salt-water in its habits than beryllina, rarely entering fresh water; and although the two species 
frequently associate in most sections of the bay, M. menidia is largely replaced by M. beryllina 
in the northern sections, and wholly so above the mouths of the rivers. It is among the most abun- 
dant of fishes in Chesapeake Bay and is present throughout the year. It was collected in large 
numbers along the shores from the time seining operations began, early in April, until late No- 
— 4V 
— ~ac 
Fig. 103. — Surface view of egg of Menidia menidia 2 days after 
fertilization, water temperature 82° F. es, embryonic shield 
3v, third ventricle of the brain; 4v, fourth ventricle; ac, audi- 
tory canal 
3-1 
D 
