554 
BULLETIN OF THE BUREAU OF FISHERIES 
Kuntz did not have sufficient material for the preparation of descriptions and 
illustrations of all the stages in the development of the young. This information is 
supplied in the following pages. 4 
Specimens 1.8 mm long . — The smallest individuals in the collection of preserved 
specimens, which we assign with some doubt to this genus because of their similarity 
to Microgobius, are only about 1.8 mm in length. Such specimens are farther de- 
veloped than a fresh or live larval fish 3.0 mm in length (fig. 13), which indicates 
that considerable contraction probably has taken place during preservation. The 
body is rather slender and somewhat compressed. The yolk is completely absorbed 
and the abdominal mass is quite small. The air bladder is plainly visible through 
the abdominal wall, lying dorsally of the abdominal mass. The intestine is free or 
at most loosely attached posteriorly and the vent is far behind midbody length. The 
finfold remains continuous but has slight indications of rays where it surrounds the 
pointed tail. The eye is excessively large, being equal to about three-fourths the 
depth of the head. The mouth is almost vertical and the snout is turned up slightly 
at the tip. The color consists of a few dark clxromatophores on the median line of 
the abdomen and on the ventral surface of the tail, that is, at the base of the ventral 
finfold (fig. 42). 
The position of the mouth in our specimens differs sharply from that shown 
in Kuntz’s (loc. cit.) illustrations (figs. 40 and 41). Figure 40, based on a newly 
hatched fish, shows an inferior mouth, and figure 13, based on a fresh fish 3.0 mm long, 
represents the mouth as terminal and only slightly oblique, and shaped very much as 
in the adult. A sudden and a pronounced change in its position must take place 
since the specimens here described cannot be much older, as already indicated, than 
the 3 .0 mm fish shown in figure 41 . Illustrations, in various works, of the development 
of European gobies, too, show that the mouth in newly hatched larvae is inferior and 
that it tends to become oblique very early in life. 
Specimens 4.0 mm long . — The body is moderately slender and notably com- 
pressed. The caudal portion of the body which is much more slender than the 
trunk in smaller individuals has become much deeper and at this size the depth just 
posterior to the vent is nearly as great as it is in advance of it. The air bladder 
remains visible, microscopically, through the abdominal walls, but the intestine 
which is partly free posteriorly in smaller specimens is now quite fully invaginated. 
4 Shropshire (1932, pp. 28 and 29, figs. 1 to 4) described four stages of young gobies under the name Gobiosoma molestrum, which 
is a synonym of G. bosci according to Ginsburgh (1933, p. 32). The two smaller stages are so different in the shape and position of 
the mouth from our series that they undoubtedly represent a different species. The two larger specimens figured could conceivably 
be identical with those of our series. 
