418 
BULLETIN OF THE BUREAU OF FISHERIES 
During four successive years an effort was made to secure the eggs by confining 
gravid fish in tanks. The overflow was screened for eggs and the tanks were examined 
carefully daily for demersal eggs, also, but none were secured. One winter (1928-29), 
for example, a fine lot consisting of 18 large spots was held for several months in a 
tank in the terrapin brooder house at a warm temperature. Although these fish 
took food (cut fish) regularly and appeared to be in good condition they, like others, 
kept in tanks out of doors (until killed by the cold), failed to cast their eggs. Those 
that died during the winter were found to contain roe which appeared to be in about 
the same state of development as in specimens examined at the time of capture in 
October. Others which either died or were killed in May (long after the spawning 
season was over) still contained roe, but the eggs showed signs of disintegration. 
This, and other experiments, indicate that the spot will not cast its eggs in captivity 
under the conditions described unless by chance very ripe individuals should be 
confined which might spawn during the first or second day of captivity. At least, 
that was our experience with the pigfish and hogchoker from which we succeeded 
in getting the eggs during the first night and a few during the second night of 
captivity, but none thereafter. 
The retention of the spawn in captivity under the conditions described is an 
interesting phenomenon, apparently well worthy of further study. The natural 
environment evidently must be more closely simulated than in the present experi- 
ments to induce the spot to carry out the spawning process. It was not determined 
what would happen eventually, whether the developing sexual products would be 
reabsorbed, discarded in an unnatural way, or whether their retention would result 
in death. It was noted only that an apparent disintegration of the eggs was taking 
place, as already stated, in those individuals retained the longest. 
We find no record in the literature of spot eggs having been taken and since 
the fish failed to spawn in captivity and the eggs, if taken in the tow, were not 
recognized, their identity and manner of development remain unknown. 
The time and duration of spawning, nevertheless, have been fairly accurately 
determined from the collections of young (larvae) made during four seasons (1927, 
1928, 1929, and 1930). The earliest young, a single specimen 3 millimeters long, was 
taken on November 12, 1927, at a station 12 miles WSW. of Cape Lookout. The 
larvae did not reappear in the collections until early in December, when they became 
numerous and remained so for several months. The smallest larvae taken during 
December, January, and February were, respectively, 1.5, 4, and 3 millimeters long. 
During the next three months — namely, March, April, and May — the smallest fry 
appearing in the collections were, respectively, 10, 7.7, and 11 millimeters in length. 
(Table 8.) 
Larvae only about 1.5 millimeters in length, without doubt, are hatched from a 
very small egg with a short period of incubation, probably not exceeding one week 
even during cold weather. This tentative conclusion is arrived at from our knowledge 
of the length of the incubation period of several other species having small eggs, 
especially the pigfish ( Orthopristis chrysopterus) which begins spawning in April 
when the waters are still quite cold. This species has an egg from 0.65 to 0.8 milli- 
meter in diameter and hatches a larva 1.5 millimeters in length. The newly hatched 
pigfish, therefore, is equal in length to the smallest spot larvae secured and it seems 
plausible that the eggs of the two species are nearly of the same size. This supposi- 
tion is supported further by the size of nearly mature eggs in the ovaries of both 
species. The incubation period of the pigfish, at the lowest temperatures that have 
