DEVELOPMENT AND LIFE HISTORY OF SOME TELEOSTS 
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usual in larger fish, and is contained 2.75 in the length to the base of the caudal fin. 
The eye and snout are of equal length, being contained 3.2 to 3.5 in the head. The 
mouth is horizontal and terminal. The brushlike teeth are developed as in the adult. 
Preopercular spines remain present, but have become very small. Scales are fully 
developed, strongly ctenoid, and the hairlike spines present on the head in smaller 
fish have disappeared. The lobes of the dorsal, anal, and the caudal fins remain 
round. The ventral fins are long, the second ray (first soft ray) being produced and 
reaching about to the base of first soft ray of the anal. 
The general color of preserved specimens varies from light to dark brown, Some 
specimens retain a trace of the pale bar crossing occiput, and the pale blotches of 
smaller specimens. A fourth dark cross bar, extending from about the middle of the 
base of soft dorsal to the base of the anal, now is more or less distinct. The dark 
brownish color of the dorsal and anal extends farther on the fins, leaving only the 
margins translucent. The caudal and pectorals remain translucent, and the ventral 
fins are mostly black. 
Specimens 40 to 50 mm long .— The body has continued to increase in depth, and 
has attained about the proportions of full-grown fish, the greatest depth being con- 
tained 1.1 to 1.2 times in the length without the caudal fin. The snout is definitely 
longer than the eye, being contained 2.75 to 3.0 times in the head, whereas the eye is 
contained 3.3 to 3.7 times. Preopercular spines virtually have disappeared, only a 
few slight points remaining at and below the angle. In somewhat larger fish they no 
longer are evident. The dorsal spines are about as high as in full-grown fish, the 
third and largest one reaching the base of the last one if deflexed. Posterior to the 
longest spine is a black membrane, which reaches beyond the tip of the spine. The 
lobes of the soft dorsal and anal have become broadly rounded, and the caudal fin is 
broadly rounded to nearly square. 
The general color is not much different from that of fish 25 to 30 mm long. A 
fifth black bar, situated on the caudal peduncle, however, is present. The color of 
the fins remains unchanged, except that the lobes of the soft dorsal and anal are wholly 
dark brown and the interradial membranes of the spinous dorsal are partly black 
(fig. 29). 
Specimens 75 mm and upward in length .- — Specimens 40 to 45 mm long already 
have acquired essentially the shape and proportions of the body of much larger fish. 
However, a notable change in the shape of the soft dorsal, anal and caudal takes 
place in larger fish. At a length of 75 mm the anterior soft rays of the anal in some 
specimens already are produced, as in large fish, making the margin straight or even 
slightly concave. The dorsal fin apparently is a little more retarded in this same 
forthcoming development. The caudal fin margin is slightly rounded to nearly 
straight in fish around 75 mm long. 
It has been indicated already that development of the fins does not proceed 
equally in all spadefish. Thus, a specimen 90 mm long has the anterior rays of the 
soft dorsal and anal produced so as to form pointed lobes, and the outer rays of the 
caudal are sufficiently produced to make the margin of this fin slightly concave. 
Another specimen, 105 mm in length, by contrast, still has these fins shaped essen- 
tially as in specimens 40 to 45 mm long. The anterior rays of the dorsal and anal, 
as well as the outer rays of the caudal continue to increase in length, though unequally 
fast, as the fish grow, and become long and pointed in large individuals, often reaching 
beyond the midlength of the caudal fin. The membrane behind the third dorsal 
spine, already present in fish 40 to 45 mm long, which is at least somewhat longer 
than the spine, persists. This spine also develops, apparently reaching its maximum 
