566 
BULLETIN OF THE BUREAU OF FISHERIES 
and as late as November 3 (1928). The young were not abundant at any time. The 
largest number of specimens was secured during July and August, which may represent 
the principal spawning period. 
It is not definitely known where this goby spawns. Tbe eggs are demersal and 
bear adhesive threads, which suggests that spawning probably takes place where there 
are sufficient objects in the water for the attachment of the eggs. Small larvae, only 
a few to several millimeters long, were taken virtually over the entire area in which 
towings were made. This area includes Beaufort Harbor, and the neighboring 
sounds and estuaries, as well as the waters off Beaufort Inlet, extending 12 to 15 miles 
offshore. It seems probable, therefore, that spawning takes place both in the inside 
protected waters and along the outside shores. 
DESCRIPTIONS OF THE EGGS AND YOUNG 
Eggs . — The eggs were described by Kuntz (1916, pp. 426-428) on the basis of 
samples stripped from fish taken and identified by the present senior author as Cteno- 
gobius stigmaticus, following Smith (1907, p. 365). The following descriptions of the 
eggs and their development is a condensed account, based on Kuntz ’s paper. The 
illustrations of the development of the egg and the figure of the newly hatched fish 
are also from Kuntz. 
The eggs are yellow in color, highly translucent, somewhat irregular in shape and 
have a diameter of about 0.3 mm. Their specific gravity is only slightly greater 
than sea water. The egg membrane is thin and delicate and usually drawn out into 
a blunt apex at the insertion of the “peduncle”, that is, at the insertion of the gelati- 
nous threads. The egg contains a relatively enormous amount of protoplasm and 
very little yolk (fig. 56). 
The fully developed blastodisc covers about half the area of the surface of the 
yolk. The first cleavage act, at ordinary summer laboratory temperature, takes place 
in about 30 minutes and the successive cleavages occur in rapid succession. The first 
cleavage plane cuts deep into the blastodisc and the first cells usually, although not 
always, are quite symmetrical. Until the 16-cell stage is reached the cells are in a 
single row. Thereafter they become heaped up on one side of the yolk (figs. 57, 
58, and 59). 
As cleavage advances the blastoderm becomes more distinctly dome-shaped and 
it soon becomes thickest at the periphery. The peripheral growth of the blastoderm 
advances and the yolk becomes entirely engulfed, the blastopore closing within 6 hours 
after fertilization (figs. 60 and 61). 
Soon after the closing of the blastopore a distinct linear thickening of the blasto- 
derm, representing the axis of the future embryo, grows anteriorly from the blastopore. 
As the differentiation of the embryonic axis advances the anterior region of the differen- 
tiated area of the blastoderm becomes distinctly broader than the posterior region. 
That is, the differentiation of the embryo begins in the anterior or head region and 
advances posteriorly (fig. 62). 
The subsequent growth of the embryo advances rapidly. Within 11 hours after 
fertilization the embryo is well formed and it shows 10 to 12 somites. An hour later 
the embryo almost completely encircles the egg and the posterior region of the body 
is already free from the greatly reduced yolk mass. The embryo, although highly 
transparent, is marked by small areas of delicate pigment. It now more than encircles 
the periphery of the egg membrane, and the entire period of incubation at laboratory 
temperature occupies not over 18 hours (figs. 63 and 64). 
