REPRODUCTION AND DEVELOPMENT OF SCIAENIDAE 
107 
The measurements made by us, which are shown in preceding pages, were all 
made in the laboratory with an eyepiece micrometer and are based on eggs taken at 
sea (exclusive of some perch eggs spawned in a tank, as stated in the text) and brought 
to the laboratory alive in water dipped up where the towings were made. The water 
used in the tank in which some of the perch eggs were spawned was pumped from 
underneath the laboratory pier at high tide when the salinometer readings generally 
average about 1.025, as compared with 1.03 off Beaufort Inlet. Therefore, all the 
measurements made at Beaufort are based on eggs spawned in salt water of rather 
high density. 
It has been shown that the eggs of two examples of gray trout measured by Welsh 
and Breder (1923, p. 151) differed markedly in size. The writers assume that some 
fish simply have larger eggs than others, and do not state whether the eggs of both 
fish were spawned in water of about even density. According to our measurements, 
the eggs of any one species, when spawned in strictly salt water, are quite uniform in 
size. Our experience, and the information gained by Delsman (1931, p. 403) and 
others, relative to the difference in the size of the eggs of one species according to the 
density of the water in which the eggs are spawned, suggest that Welsh and Breder 
may have used water of very unequal density in which the eggs of the two samples 
of trout mentioned presumably were artificially spawned. Certainly we must con- 
sider the large variation in the diameter of the trout eggs given by the writers men- 
tioned as unusual. In fact such a wide variation, under identical conditions, would 
suggest the presence of two races. 
DISTRIBUTION OF THE YOUNG 
It has been stated in the section of this paper dealing with the spawning (p. 104) 
of tins species that the young, 10 millimeters and less in length, are much more numer- 
ous off Beaufort Inlet than in the harbor and adjacent sounds and estuaries. Some- 
what larger fish, too, appear to be rather more numerous in the outside than the inside 
waters, although they tend to congregate and become abundant in certain restricted 
areas in the estuaries. For example, the young ranging from about 15 to 100 milli- 
meters in length are very numerous above “cross rock” in Newport River during the 
summer or after the middle of June. The water is only a foot or two deep above cross 
rock at low tide and the bottom is very muddy. The water generally is brackish, 
but the density fluctuates greatly, depending upon the stage of the tide and the rain- 
fall, as this mud flat is only a short distance from the mouth of the narrow channel of 
Newport River where this stream discharges fresh water into its estuary. 
Pearson (MS.), too, found that young gray trout when about 8 to 10 millimeters 
long “settle on the bottom” in Chesapeake Bay in coves and creeks at Lynnhaven 
Roads and elsewhere. 
Soft or muddy bottom seems to be preferred by the young during the first sum- 
mer. Those that remain in the ocean, as well as those that enter the harbor, seem to 
seek muddy bottom. For that reason, presumably, the young are numerous in the 
vicinity of the sea buoy off Beaufort Inlet where the bottom is soft. It is presumed 
that the young fish find food abundant on the mud. However, the food require- 
ments of the young under about 40 millimeters in length have not been studied. 
Larger ones, according to Welsh and Breder (1923, pp. 159-164), feed on a variety of 
forms, including copepods, amphipods, isopods, shrimps, crabs, worms, and fish. 
