404 
BULLETIN OF THE BUREAU OF FISHERIES 
Figure 30 . — Orthopristis chrysopterus. Young fish, 4.9 millimeters long 
Figure 31 . — OTthopristis chrysopterus. Young fish, 6.7 millimeters long 
is curved upward more strongly than previously. The dorsal and anal fins are be- 
coming differentiated but, as yet, do not contain definitely developed rays. An 
expansion of the fin fold on the distal part of the tail gives the appearance of a third 
dorsal fin, which, however, fails to develop and gradually disappears. (Fig. 31.) 
Specimens 10.0 millimeters 
long. — The body has continued 
to increase in depth, and it 
has become definitely com- 
pressed, the depth being con- 
tained in the length to the 
base of the caudal fin about 6.0 times. The mouth is now somewhat less vertical 
than in the smaller stages, but it remains much more oblique than in the adult. The 
soft dorsal and anal fins are far enough developed to admit of a fairly accurate count 
of the rays. The spinous dorsal and the ventral fins remain undeveloped. The 
caudal fin is well formed, 
and its margin is somewhat 
emarginate, approaching in 
that respect the forked shape 
of the adult. The noto- 
chord, now sharply bent 
upward, remains only faintly visible. Pigmentation is becoming evident in preserved 
specimens in the darkened margins of the opercle and preopercle, in the darkened 
distal ends of the finrays, and the broken, black crosslines on the caudal fin. (Fig. 32). 
Specimens 11.0 millimeters long. — The principal changes from the previously 
described size are in the 
appearance of the spinous 
dorsal — a few spines hav- 
ing become slightly devel- 
oped — and in the first 
appearance of the ventral 
Figure 32 .— Orthopristis chrysopterus. Young fish, 10 millimeters long The notochord initS 
sharply upward-curved position posteriorly, remains only faintly visible. The depth is 
now contained in the length to the base of the caudal fin about 5.3 times. (Fig. 33.) 
Specimens 15.0 millimeters long. — The head and body have increased in depth 
and are notably compressed, the depth being contained in the length about 4.2 times. 
The mouth is only slightly 
more oblique than in the 
adult. The upward-curv- 
ed notochord — that is, the 
heterocercal character of 
the tail — has completely 
disappeared The spi- Figure 33.— Orthopristischrysopterus. Young fish, 11 millimeters long 
nous dorsal is now partly developed, about 7 spines usually having appeared well in 
advance of, and entirely separate from, the soft dorsal. Variation in this respect 
has been noticed, as in some specimens of this size the spinous dorsal is further de- 
veloped than in others. Pigmentation has progressed rather rapidly. A dark lateral 
band which aids greatly in identification has developed, the lips and snout are more 
or less dusky, small areas of dark chromatpphores are present on the head and on the 
back, and scattered dusky dots occur along the base of the anal fin. (Fig. 34.) 
