NATURAL HISTORY OF REDFISH, ETC., OF TEXAS 



165 



Little information on the spawning habits of the black drum in other sections 

 of its range has been recorded. Welsh and Breder (1923, p. 197) stated that the eggs 

 and larvie of the drum were unrecorded and that little was known of the life history. 

 Hildebrand and Schroeder (1928, p. 288) recorded a fully ripe male drum, 37 inches 

 long, taken on May 22, 1922, at Cape Charles, Va., in 48 feet of water, but stated 

 that no young drum under 8 centimeters (3 inches) have ever been secured. 



GROWTH AND AGE 



Study of the age and growth of the black drum brought out the fact that by 

 the method of age determination employed with success in the case of the redfish, 

 croaker, and spot (the Petersen method, whereby the individuals of a large collection 

 are grouped according to their length, and each prominent mode or hump in the 



NO. 



FISH 



20 



20 



20 



20 



20 



20 



m. 3S 7.8 M !S.7 197 23.6 27.5 31.5 39 7.6 II.S 15.7 19.7 23$ 27.5 31.5 35.4 



1! 



i 



APS. 



4 - 



MM 



nAY 



JUN. 



8, 



I92B 



JUN. 



JUL 



.^^ 



DEC. 



NOV 



OCT. 



JAN 



10- 



DEC 



25, 



NOV. 



1927 







ens. 10 20 30 40 50 60 70 60 10 20 30 40 50 60 70 80 50 



Fig. 20. — Length-frequency distribution of black drum in Texas, 1926-27. Actual frequencies have been 

 smoothed by a moving average of threes. Roman numerals indicate year classes 



plotted frequency distribution is assumed to represent an age class), only the first 

 two year classes of drum could be discerned throughout the year with any degree 

 of reliability. After the third year the various year classes overlap to such an 

 extent as to render the Petersen method worthless. 



A series of jmoothed length-frequency distributions, taken from Table 15, is 

 presented in appro.ximate monthly summaries by Figure 20. Collections from April 

 4 to May 8, 1926 (following fig. 20), gave a group of drum (I-year class) assumed 

 to be entering their second year with a modal length at about 25 centimeters (9.8 

 inches). This I-year class grew rapidly durmg the succeeding months, and by 

 October (September 12 to October 8) had reached a modal length of about 35 cen- 

 timeters (13.7 inches). While this class held its original identity well during the 

 spring and summer of 1926, it nearly disappeared from the catches during the 



