FISHES OF CHESAPEAKE BAY 
323 
KEY TO THE GENERA 
a. Body entirely naked; mouth nearly horizontal; second dorsal and anal short, each with 10 to 14 
rays Gobiosoma, p. 323 
aa. Scales present on at least most of body; mouth oblique to nearly vertical. 
b. Teeth in the jaws in bands, immovable; lower jaw rather strong, round anteriorly; second 
dorsal and anal rather long, each with 15 to 18 rays Microgobius, p. 325 
bb. Teeth in the jaws in a single series, movable; lower jaw very thin and angular anteriorly; 
second dorsal and anal short, each with about 11 or 12 rays.. Mugilostoma gen. nov., p. 327 
139. Genus GOBIOSOMA Girard. Naked gobies 
Body rather slender; mouth moderate, nearly horizontal; teeth pointed, in several series or 
in a band, the outer ones enlarged; no canines; skin entirely naked; no barbels or dermal flaps; 
spinous dorsal normally with 7 spines, rarely 5 or 6; second dorsal and anal short, with 10 to 14 
rays; ventral fins united, forming a sucking disk. 
KEY TO THE SPECIES 
a. Body moderately robust, its depth 3.95 to 4.8 in its length; second dorsal normally with 13 
rays, infrequently with 12 or 14; ventral disk short, reaching about half the distance from its 
base to the vent bosci, p. 323 
aa. Body slender, its depth 6 to 7.15 in its length; second dorsal normally with 12 rays, infrequently 
with 11 or 13; ventral disk long, reaching two-thirds the distance from its base to the 
vent ginsburgi sp. nov., p. 324 
178. Gobiosoma bosci (Lac6pede). Clinging goby; Variegated goby; Naked goby. 
Gobius bosci LacSpede, Hist. Nat. Poiss., II, 1798, p. 555, Pi. XVI, fig. 1; Charleston, S. C. 
Gobiosoma bosci Bean, 1891, p. 86; Jordan and Evermann, 1896-1900, p. 2259; Smith and Bean, 1899, p. 187; Evermann and 
Hildebrand, 1910, p. 163. 
Head 3.15 to 3.5; depth 3.95 to 4.8; D. VII or VIII-13 (infrequently 12 or 14); A. 11 (rarely 
10). Body robust; head depressed, broader than deep; snout short, tapering, 3.45 to 4.25 in head; 
eye 3.25 to 4.67; interorbital bone about the width of pupil; mouth moderate, terminal; maxillary 
reaching about opposite middle of eye, 2.25 to 2.4 in head; teeth in the jaws pointed, in bands 
in each jaw, with some of the outer teeth enlarged; gill openings mostly lateral, the membranes 
joined to the isthmus; pores usually present on the cheeks; dorsal fins close together, the first 
consisting of very slender spines, the margin convex; second dorsal and anal similar and opposite 
each other, the rays of the dorsal reaching to or beyond the base of the upper short rays of the 
caudal; caudal fins short, round, shorter than head; ventral fins short, forming a disk, the disk 
scarcely reaching more than half the distance from its base to the vent, its length 1.65 to 2.45 in 
head; pectoral fins broad, a little shorter than head, 3.25 to 4.7 in the length of body. 
Color in life greenish to dusky above; pale underneath; nape and sides with very narrow pale 
crossbars; pectoral fins mostly greenish; other fins mostly blackish; the caudal of a somewhat 
lighter shade than the dorsals. Considerable variation in color among individuals has been noted, 
some specimens being notably darker than others, and the males in general appear to be darker 
than females, with the pale crossbars showing less distinctly. 
Many specimens, ranging from 25 to 60 millimeters (1 to 2% inches) in length, were preserved. 
This goby is entirely naked. Its body is quite robust, the head is depressed, and the ventral disk 
is very short, scarcely reaching more than halfway to vent. 
In a series of 37 specimens examined for the food contents of the stomachs, 12 had fed on small 
crustaceans (mainly Gammarus), 14 had eaten annelids (Chsetopods), 2 had fed on fish, and 2 
on ova of unknown origin. Two individuals had fed on both Gammarus and annelids, and 9 stom- 
achs were empty. 
Spawning apparently takes place from June to October. The gonads in many of the speci- 
mens taken in July are in an advanced stage of development, and it seems probable that most of 
the spawning takes place during this month. However, a few specimens taken during the early 
