546 
BULLETIN OF THE BUREAU OF FISHERIES 
Soft dorsal and anal each with 
11 to 14 rays. 
A dark sheath present above air 
bladder, not crescent-shaped. 
Length 6.0 to 7.5 mm 
Soft dorsal and anal each with 
16 or 17 rays. 
A dark sheath over air bladder 
as in Gobiosoma. 
Soft dorsal and anal each with 
11 to 13 rays. 
A distinct crescent-shaped dark 
area over air bladder. 
The differences listed in the shape of the body for smaller specimens apply to fish 6.0 to 7.5 mm 
long. 
Length 8.0 to 12 mm 
Body anteriorly rather robust 
somewhat rounded; head 
slightly depressed, as broad 
as deep. 
Mouth rather small; maxillary 
reaching about opposite an- 
terior margin of eye. 
Body and head compressed, 
rather deep. 
Mouth large, maxillary reaching 
opposite anterior margin of 
pupil. 
Body more or less round and 
very slender. 
Mouth small; maxillary scarcely 
reaching opposite anterior 
margin of eye. 
The differential color markings mentioned for smaller fish remain as described in specimens 
6.0 to 7.5 mm long. 
Length 13 to 16 mm 
Body anteriorly quite robust; 
head notably depressed. 
Mouth only slightly oblique, 
terminal; maxillary reaching 
only slightly beyond anterior 
margin of eye. 
Dorsal spines all about equally 
spaced. 
Head and body compressed 
throughout. 
Mouth large, strongly oblique, 
terminal to slightly superior; 
maxillary reaching nearly op- 
posite middle of eye. 
Dorsal spines as in Gobiosoma. 
Body extremely slender, remain- 
ing round. 
Mouth moderately oblique, 
small, terminal; maxillary 
scarcely reaching opposite an- 
terior margin of eye. 
Last two dorsal spines much 
farther apart than the others. 
A COMPARISON OF THE EGGS AND THE YOUNG OF SOME AMERICAN AND 
EUROPEAN GOBIES 
It has been shown in the preceding paragraphs that the eggs of all the Ameri- 
can and European gobies that have been studied have adhesive threads or an adhesive 
foot by which the eggs become attached to submerged objects. A further comparison 
of the eggs, and the young, of the American and European species shows other simi- 
larities. The eggs of all the gobies, so far as they are known, are rather small. A 
dozen eggs of Gobiosoma bosci measured by us several hours after fertilization, when 
they had had time to expand, bad a length of 1.2 to 1.37 mm, and their greatest width 
was 0.52 to 0.59 mm. The eggs of Ctenogobius stigmaticus (— Gobionellus boleosoma ), 
according to Kuntz (1916), are extremely small, having an average diameter of only 
0.3 mm. The eggs of European species, too, are rather small. Ehrenbaum (1905) 
gave the following lengths of the eggs for the European species named: Gobius ruthen- 
sparri, 0.7 mm; G. paganellus, 1.8 to 1.9 mm; G. pidus, 0.8 mm.; and G. niger, 1.5 mm. 
Lebour (1920) gave the length of the eggs of G. microps and G. minutus respectively 
as 0.85 to 1.0 and 1.08 to 1.4 mm. 
The eggs of Gobiosoma bosci when first spawned, as stated by Kuntz (loc. cit.) 
and verified by us, are nearly spherical. After fertilization they expand and become 
eliptical, the greater axis becoming nearly twice as long as the lesser one. The adhesive 
foot, consisting of a bundle of threads, remains attached to one pole of the longer axis. 
The eggs of Ctenogobius stigmaticus (= Gobionellus boleosoma ) according to Kuntz" (loc. 
cit.) are more or less irregular or variable in shape, and they remain so throughout 
the incubation period. 
