534 
BULLETIN OF THE BUREAU OF FISHERIES 
The range in length of 311 young taken during July under the same general 
conditions and over the same number of seasons is 11 to 42 mm, the average length 
being 21.8 mm. 
In August the range in length of 79 specimens, from the same localities and the 
same years, is 27 to 44 mm having an average length of 36.6 min. 
In September only 20 specimens, ranging in length from 38 to 47 mm, with an 
average length of 42.1 mm, were secured. 
It seems probable that the measurements for July alone show fairly accurately 
the range in length, as well as the average size, of the young fish for that month. 
In June the smallest young of the season had not arrived in the weeded areas. There- 
fore, the lower limit of the range, and consequently the average length, are not 
correct. By August some of the larger young had left the weeded areas, and therefore 
the upper end of the range, as well as the average, is incorrect. In September the 
fish had gotten so scarce that with the same fishing effort put forth each month in 
1926 only 20 specimens were secured, whereas in August 69 were taken, in July 299, 
and in June 36. 
The data seem to justify the conclusion, however, that in June the largest young 
of the current season are around 20 to 25 mm long, the lower limit of the range and 
the average length being unknown. In July young range in length from about 11 
to 42 mm, and the average length is close to 21.8 mm. In August the smallest 
young are about 27 mm long, and in September they are around 38 mm in length, 
the upper limit of the range and the average length being unknown for both months. 
A fairly slow rate of growth seems to be indicated if the evidence produced 
elsewhere, showing that spawning at Beaufort begins sometime in April and ends 
near the end of June, is correct. A slow rate of growth and late maturity would 
explain, in part at least, why the sheepshead has diminished rapidly under heavy 
fishing, whereas other, presumably faster-growing, species have withstood it without 
a serious decline. 
CHAETODIPTERUS FABER (BROUSSONET). SPADEFISH 
The development of the eggs and recently hatched larvae of the spadefish was 
described and figured by Ryder (1887, pp. 521-523). It is possible now to describe 
and figure some more advanced stages, though the series is not yet as complete as 
desirable. 
Professor Ryder did not state specifically that the eggs used in his study were 
taken directly from ripe fish caught in Chesapeake Bay, though this apparently may 
be assumed. He merely said, “This species spawns in the Chesapeake during the 
latter part of June and the early part of July. It is prodigiously fertile, the female 
probably discharging a million ova during a single season.” It must be further 
stated, however, that the number of eggs deposited probably depends on the size of 
the female, because large fish generally, if not always, produce more eggs than smaller 
ones of the same species. 
The eggs were not seen by us. Ryder states that they are pelagic, “somewhat 
over a millimeter in diameter”, and have a single oil globule. Cleavage took place 
rapidly, as only an hour intervened between the first cleavage and the morula stage. 
Hatching took place in about 24 hours in a water temperature of 80° F. 
The newly hatched fish were “about 2.5 mm in length.” In 63 hours the yolk 
was nearly all absorbed, young fish had increased greatly in depth, and were nearly 
4.0 mm long. The snout was very blunt, the mouth (according to the figure) was 
