508 
BULLETIN OF THE BUREAU OF FISHERIES 
It will be seen from the following accounts that generally many gaps remain in 
the series of developmental stages of the various species treated. However, in every 
case enough new information is presented to make publication seem quite worth while. 
It has been possible, at least for some of the species discussed, to determine from 
the time and place of collection of the eggs or early young or both, the approximate 
duration of the spawning season and also the place of spawning, even though ripe fish 
were not seen. The movements or migrations of the young, too, were determined for 
some of the species from the places of collection of immature fish. Considerable in- 
formation relative to the rate of growth during the first several months of life also was 
gained for several species, and is shown in tables and graphs presented. 
All the species discussed in this paper, exclusive of the pinfish and the hakes, 
spawn during the summer, and either are scarce or absent in the local shallow water 
during the winter. The pinfish and the hakes, however, spawn during autumn and 
winter, and the young sometimes were taken in large numbers during the winter in 
company with young spots and croakers, the last named species also being winter 
spawners, as shown in an earlier paper by the writers (1930, pp. 417 and 433). 
The drawings of the eggs and newly hatched fish are based on living material. 
All the rest of the illustrations were prepared from preserved specimens. 
SCOMBEROMORUS MACULATUS (MITCHILL). SPANISH MACKEREL, 
WITH NOTES ON RELATED SPECIES 
The development of the eggs and the early larvae, up to 6 days of age, of the 
Spanish mackerel was described and figured by John A. Ryder (1882, pp. 135-172). 
It is now possible to describe and figure some older stages of Scomberomorus. 
The eggs used in Professor Ryder’s study were secured directly from ripe fish at 
several different points in Chesapeake Bay. The eggs, according to Ryder, float in sea 
water and vary in size from “one-twenty-fifth to one-twentieth of an inch in diameter.” 
They generally hatched in 24 hours. Segmentation proceeded quite regularly, as 
usual in teleostean eggs. The newly hatched fish was scarcely 2 mm long. When 3 
days old the larvae had absorbed the contents of the yolksac, and the mouth was wide 
open. On the sixth day after hatching (length not stated), according to Ryder’s 
figure 17, the mouth had grown very large and wide with a sharp angle at the joints 
of the lower jaw. Prominent teeth already were present. This is the most advanced 
larva described and figured (anterior part of body only) by Ryder, and it seems to be 
identifiable with the smallest larvae now at hand. 
The specimens upon which the present study is based were caught in nets, mostly 
on the coast of North Carolina in the vicinity of Beaufort. However, among the 
larger young, specimens from Massachusetts, South Carolina, Georgia, Florida, 
Louisiana, Cuba, St. Lucia, and Panama also have been studied. All the larvae 
under 14 mm in length were taken at sea and mostly several miles offshore along 
the coast of North Carolina. Neither the larvae nor the older young were found 
numerous during the extensive collecting done in the vicinity of Beaufort. Never- 
theless, adult Spanish mackerel occur there in season (spring and fall) in sufficient 
abundance to be of considerable commercial value. However, comparatively few 
seem to remain during the spawning season. 
The ceros (locally pronounced “zero”) or kingfish, S. cavalla and S. regalis, are 
too scarce (especially the last named one) on the coast of North Carolina to be of 
much commercial importance. They are sought, however, by sportsmen, who prefer 
them to Spanish mackerel because they run larger in size. S. cavalla sometimes 
