SCL33NIDJE OF THE EASTERN UNITED STATES COAST. 
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yolk sphere. Shortly thereafter (fig. 5) yellow chromatophores appear along the 
sides of the embryo and on the surface of the oil globule. In about 18 to 20 hours 
after fertilization (fig. 6) the embryo extends halfway round the yolk, and the 
number of chromatophores has greatly increased. In certain areas the yellow 
chromatophores are more or less grouped, especially behind the eye, in a transverse 
band behind the otocyst and on the underside of the snout. The median ventral 
sin-face of the body is practically free from pigment. Scattered black chromato- 
phores are present on the dorsal surface of the body and on the oil globule. Yellow 
chromatophores persist on the surface of the yolk sphere, either aggregated or evenly 
scattered. Figure 7 shows the appearance of the embryo shortly before hatching. 
The period of incubation at water temperatures of from 68 to 70° F. (20 to 
21° C.) is 36 to 40 hours. The newly hatched larvae (fig. 8) are approximately 
1.75 mm. in length; the yolk sac is relatively large, and the oil globule lies at its 
posterior end. The vent lies immediately behind the yolk sac. The arrangement 
of the chromatophores is essentially the same as in later stages within the egg, 
but they appear to be less numerous. In about eight hours after hatching (fig. 9) 
the yellow pigment spots are aggregated about the eye and behind the otocyst 
and form two more or less distinct bands upon the body behind the vent, and 
the yolk sac has decreased slightly in size. When about 24 hours old (fig. 10), 
the length has increased to approximately 2.2 mm., the yolk sac is much reduced, 
and the oil globule occupies a more median position. The pectoral fins are dis- 
tinct. The arrangement of the pigment is similar to that of the preceding stage, 
with the addition of a band of yellow chromatophores near the caudal extremity 
of the body. (In these figures black pigment is indicated by solid black, and 
yellow pigment by stippling.) 
No examples of early post-larval forms of Cynoscion regdlis are present in the 
collections now available, but fortunately this gap is filled by the excellent account, 
with figures, of two specimens 6.5 and 12.5 mm. long, given by Henry C. Tracy 
in the Report for 1908 of the Commissioners of Inland Fisheries of Rhode Island 
(Tracy, 1908). His illustrations are here reproduced (figs. 11 and 12), and the 
accompanying descriptions are condensed from his account. The two specimens 
figured were taken with about a dozen others, of intermediate sizes, on July 28, 
1907, in Mill Cove, Wickford Harbor, R. I., having been found in the canvas bags 
used in the rearing of young lobster fry. (Some of these fish were kept alive until 
October, by which time they were large enough to afford a certain identification.) 
In the specimen 6.5 mm. long (fig. 11) the larval fin fold has not yet disap- 
peared, although the rays of the vertical fins are well differentiated. The head is 
rounded in profile, and teeth are present. Along the lateral line is a row of about 
eight rather large chromatophores, forming two groups, one above the anal and 
the other below the anterior part of the soft dorsal, each group having a few smaller 
chromatophores above and below it. A large chromatophore lies at the base of 
the anal fin. To the naked eye the effect is of two grayish or dusky bands upon 
the sides, the posterior one being more conspicuous. Other large chromatophores 
are found on the underside of the head, at the base of the spinous dorsal, and on 
the ventral edge of the caudal peduncle. The pigmentation of the posterior part 
of the body cavity is also visible. 
