446 
BULLETIN OF THE BUREAU OF FISHERIES 
This flyingfish, when adult, is characterized by the rather short pectorals which 
reach only to about the middle of the dorsal base and are colorless. The dorsal and 
anal bases are equal in length, and the snout is short and blunt. The adult characters 
are acquired by the young fish at a comparatively small size. The maximum size 
attained is only about 175 millimeters (7 inches). Its life history seems to be little 
known. 
SPAWNING AND DEVELOPMENT OF YOUNG 
Figure 60.— Parexocoetus mesogaster. From a specimen 5 millimeters long 
The eggs of this species have not been taken or, at least, not recognized. Very 
small fry, ranging from 3 millimeters upward, were common 20 miles and more off 
Beaufort Inlet in August and September, 1914. Fry only 3 millimeters or so in 
length, obviously, are very young and it may be concluded from their presence on 
the coast of North Carolina that spawning takes place there during the summer. 
Specimens 3 millimeters long. — The body is rather more compressed at this size 
than in the adult, although it is already elongate and shapely. The mouth is vertical 
and the eye is very large. The vent is situated far behind the middle of the body 
and all the fins already are evident, although only the caudal contains definite rays. 
Some specimens at this size already are profusely dotted with black. (This size was 
not drawn, because no perfect specimens are at hand, and, furthermore, the difference 
between a 3 and a 5 millimeter fish, which was drawn, is not pronounced.) 
Specimens 5 millimeters long. — The body has become a little more robust since 
a length of 3 millimeters was attained and the caudal fin, which was nearly square 
previously, now has the lower 
rays somewhat produced. 
Rays have definitely developed 
in the pectoral fins, but none 
is clearly outlined in the ven- 
trals — dorsal and anal. The 
development of rays in the pectoral fins prior to their appearance in the dorsal and 
anal is unusual, as the reverse apparently is true in most fishes. Early development 
of the pectorals probably takes place because they are destined to become very large 
fins. Pigmentation varies considerably among preserved specimens. The majority 
of them appear to be rather profusely dotted with black, although others are quite 
plain brownish. (Fig. 60.) 
The vertical mouth, the very large elongate eye, the almost straight margin of the 
tail with a few of the lower rays produced, and the presence of dark dots at least on 
the head are the most outstanding characters of the larval Parexocoetus mesogaster . 
Specimens 10 millimeters long. — The body is elongate, somewhat compressed, and 
proportioned much as in the adult. The head is comparatively small and slightly 
depressed above. The mouth is very strongly oblique but not quite vertical, as in 
the smaller fry. The fins are all well developed; the pectoral fins are about two- 
thirds the length of the head; the ventral fins are large, reaching nearly or quite to 
the origin of the anal; the caudal fin is short above, the rays increasing gradually 
in length to about the second or third from the lowermost one, the longest rays 
being nearly twice as long as the shortest. The margin of the fin, therefore, is almost 
straight and rather strongly oblique. Pigmentation consists of a general brownish 
cast, the head being paler than the rest of the fish, and the entire body is profusely 
dotted with black chromatophores, which are crowded along the median line of the 
side, forming an almost continuous dark line. A few chromatophores also are present 
on the base of the caudal and extend slightly on the base of the longest rays, the fins 
