454 
BULLETIN OF THE BUREAU OF FISHERIES 
therefore, that spawning takes place at sea and probably anywhere from the shores 
to, and possibly beyond, the Gulf Stream. The smallest fry taken are only about 
2 millimeters long, which suggests that the scad produces very small eggs. 
DESCRIPTIONS OF YOUNG 
The young fish in the present collection range from about 2 to 50 millimeters 
in length and within this range the series is fully complete, as all sizes are represented 
by numerous specimens. However, no specimens ranging from 50 to 175 millimeters 
in length are at hand. Therefore, young ranging upward of 50 millimeters are not 
described. 
Specimens 2.3 millimeters long . — The head is excessively large and deep and some- 
what compressed. The body tapers posteriorly to a sharp point. The dorsal profile 
of the head is deeply concave, the snout being directed upward. The mouth is large 
and nearly vertical, and the tip of the lower jaw is above the level of the upper margin 
of the eye. Comparatively large spines are present on the preopercular bones. 
(These spines disappear at an early age, or when the fish reaches a length of about 20 
millimeters and the preopercular margin, thereafter, is smooth and entire.) Pectoral 
fin folds are prominent but 
the ventral fins are not evi- 
dent at this size, nor in con- 
siderably larger specimens. 
The vent is prominent and 
is situated somewhat pos- 
terior to mid-body length. 
A few dark markings usu- 
ally are evident along the 
dorsal and ventral outlines 
of the body at the base of 
the fin fold. Although the 
fish must be very young at this size, the yolk is all absorbed and the head is fairly well 
in line with the axis of the body. (Fig. 68.) 
Young of this size are remarkable on account of their deep heads, turned up 
snout, and long spines on the preopercular margin. 
Specimens 3.5 millimeters long . — At this size the head is not as disproportionately 
large in comparison with the rest of the fish as in the 2.3 millimeter specimens, for 
the body has gained greatly in depth, except in the distal part of the tail which re- 
mains slender and pointed. The fish is quite strongly compressed and very unlike 
the adult in this respect. The concavity in the dorsal outline of the head is slightly 
less pronounced, and the mouth is a little less strongly oblique than in the smaller fish 
described. The fin fold remains complete and extends from the nape around the tail 
and forward to the abdomen. The dark chromatophores on the dorsal and ventral 
outlines of the body, especially on the caudal region, have increased in number and 
intensity. A few dark chromatophores, also, are present on the median line of the 
side, posterior to the vent. 
The presence of dark chromatophores on the median line of the side are very 
helpful in recognizing young scad of this size and larger ones, for this row of black 
chromatophores persists and is prominent until a length of at least 10 to 12 milli- 
meters is attained. At that size the fin rays are developed and identification can be 
based largely on adult characters. 
