FOURTEEN TELEOSTEAN FISHES AT BEAUFORT-, N. C. 397 
It appears to be of interest to mention, also, that the larger fish are the first ones 
to migrate away from the local waters in the autumn. No large fish appeared in our 
collections after the early days of November and some evidence, as shown subse- 
quently, has been obtained indicating that even the largest young of the current 
season — namely, the largest representatives of the O class- — leave the shallow waters 
somewhat earlier than the smaller fish of the same year class. On the other hand 
the older and larger fish are the first ones to return the following spring, some in 
March and many more in April. 
The smaller young of the previous year, now the I class, do not appear to get 
back until about June, for the smallest individual taken of the older year classes in 
April was 175 millimeters long; the smallest one caught in May was 125 millimeters 
in length; and in June the smallest fish, evidently belonging to the 1-year class, were 
105 millimeters long. (One specimen, probably belonging to this class, had a length 
of only 92 millimeters.) Fish of the last-mentioned size compare well with the 
smallest fish of the O class taken in November, which were 87 millimeters in length. 
Owing to the emaciated condition of the fish when they return from their winter 
habitat, one would not expect rapid growth. Their growth after returning to their 
summer home, however, appears to proceed rather rapidly, for the smallest fish in 
our collections assigned to the 1-year class taken in July was 145 millimeters long; 
the smallest ones in August were 150 millimeters long; in September and October 
the smallest fish for each month were 160 and for November 165 millimeters. It is 
rather certain that some of the smaller individuals of the I class are missing in the 
catches for July, as it is improbable that fish only 105 millimeters long in June had 
attained a length of 145 millimeters in July. Furthermore, the gap in length measure- 
ments for June between the O and I classes had almost closed, whereas in the July 
measurements an interval reappears, extending from 112 millimeters, the largest 
representatives of the O class, to 145 millimeters, the smallest representatives of the 
older year classes. In August the gap in the measurements again is almost closed, 
and it remained so during the rest of the summer. 
A record of water temperatures taken daily at 4.30 p. m. at the laboratory pier 
shows a rather close similarity when comparisons are made for the months during 
which the principal pigfish migrations take place. That is, the temperature in 
March, when the fish usually begin to return to the shallow waters, are near those 
that prevail in November when the last ones leave. Similarly, the temperatures for 
April and October, the months when the main body of pigfish migrates, are not 
very different. The range in temperature and the averages, expressed in degrees 
centigrade, for the 4-year period, namely, 1926 to 1929, for the months during which 
the principal pigfish migrations take place locally, are shown in the accompanying table. 
Table 2.- — Comparison of the average water temperature ( centigrade ) at Beaufort, N. C., in March 
and April with that of October and November from 1926 to 1929 
Month 
Minimum 
Maximum 
Average 
Month 
Minimum 
Maximum 
Average 
6 
22 
14.3 
October 
16 
30 
22 2 
Apr’i 
13 
23 
18.3 
November 
8 
25 
16.3 
Since the temperatures given in Table 2 were taken just beside one of the 
principal channels between Beaufort Harbor and the estuary of Newport River, 
many fish in their migrations no doubt pass the place where the records were obtained; 
■2 
2698-30- 
