REPRODUCTION AND DEVELOPMENT OF SCIAENIDAE 
101 
or reticulations of the adult begin to appear when the fish reach a length of about 
100 millimeters, and at a length of about 120 to 130 millimeters the fish have acquired 
almost fully the color pattern of the adult. 
C. nebulosus is more slender and more shapely than C. regalis throughout the 
younger stages. However, at a length of about 175 millimeters the differences in 
the shape of the body virtually have disappeared. It is evident from table 3 that 
C. nebulosus acquires the proportionate depth of the adult very early, that is, at a 
length of about 10 to 12 millimeters, whereas C. regalis is much deeper throughout 
the younger stages and does not have the proportionate depth of the adult until a 
length of about 175 millimeters is attained. 
The shape of the caudal fin differs quite notably in the two species throughout 
the younger stages, that is, from a length of about 20 to 125 millimeters. During 
this entire period of development this fin, although pointed in both species, is notably 
longer in C. regalis than in C. nebulosus, the longest rays in the former being the middle 
ones, which are more or less filamentous in the younger stages, and equal to or longer 
than the head, whereas the longest rays in the latter are in the lower half of the fin 
and are not longer than the head. For some time during the course of development 
the upper lobe of the caudal fin in both species is slightly concave and the lower 
lobe more or less roundish. Although the fin must undergo a greater change in C. 
regalis to acquire the broadly concave outline which obtains in adults of both species, 
it is acquired somewhat earlier, that is, at a length of about 250 to 280 millimeters 
(there being much variation in the development among specimens), whereas this 
shape is not acquired by C. nebulosus until the fish is about 300 millimeters long. 
The two species differ also in the number of gill rakers, C. regalis having 11 or 
12 on the lower limb of the first arch, whereas C. nebulosus has only 7 or 8. The 
gill rakers are developed and can be counted readily when a length of about 26 milli- 
meters is attained. 
The species differ, furthermore, in that C. nebulosus has no scales on the fins 
throughout life, whereas C. regalis has minute scales on about the basal half of the soft 
dorsal, the caudal and the anal fins. The scales first appear when the fish are about 
45 to 55 millimeters long. 
Table 3. — -Proportionate depths of specimens of various size of Cynoscion nebulosus and C. regalis 
C. nebulosus 
C. regalis 
C. nebulosus 
C. regalis 
Total length in 
millimeters 
Depth in 
standard 
length 
Number 
of 
specimens 
measured 
Depth in 
standard 
length 
Number 
of 
specimens 
measured 
Total length in 
millimeters 
Depth in 
standard 
length 
Number 
of 
specimens 
measured 
Depth in 
standard 
length 
Number 
of 
specimens 
measured 
7 
3.3 
1 
2.8 
1 
70-90 
3. 7-4. 0 
7 
3. 4-3. 6 
3. 5-3. 6 
3. 5-4. 1 
4. 1-4.4 
7 
5 
4 
6 
10-12 
3. 8 -4. 2 
3 
2. 95-3. 0 
3 
120-130- 
3. 8-4. 1 
5 
16-20 
3. 9 -4. 15 
3 
3. 3 -3. 4 
3 
150-175- 
3. 9-4. 25 
4 
25-30 
3. 95-4. 2 
6 
3. 3 -3. 5 
6 
210-240. 
4. 1-4. 3 
6 
40-50 
4. 0 -4. 25 
6 
3. 3 -3. 4 
6 
DISTRIBUTION OF THE YOUNG 
It has been stated elsewhere (p. 93) that the young under 5 millimeters in length, 
in the collection mostly were taken at off-shore stations. The larger ones of the 
same year class, ranging from 5 millimeters upward, however, were all caught in 
inside waters. The indications are, therefore, that the young, if actually hatched 
in part off shore, enter the inside waters soon afterward. 
