PROGRESS IN BIOLOGICAL INQUIRIES 



9 



thought best to test these preliminary findings and provide an objec- 

 tive proof of the wanderings of the mullet. Accordingly, a tagging 

 experiment was undertaken, and 3,000 mullet were tagged and liber- 

 ated near Beaufort, N. C. About one-third of the fish tagged were in 

 their first year and the rest were in their second. By the end of Decem- 

 ber, 34 tags had been returned by fishermen. 



Table 5. — Summary of mullet-tagging experiments 



All tagged fish were recaptured within the boundaries of North 

 Carolina except one near Georgetown, S. C, 170 miles from Beaufort. 

 This fish traveled the maximum distance from the place of libera- 

 tion and did so in 52 days. The longest time that elapsed between 

 liberation and recapture was 119 days. While these returns are insuf- 

 ficient to outline fully the migrations of the mullet, the indications 

 are that the southward migration along the coast begins, at Beau- 

 fort, in August, continues during September, and is completed in 

 October. Some fish, however, remain in fresh or brackish waters of 

 the rivers during the winter, apparently not taking part in the annual 

 migration. These observations are in accord with popular opinion 

 in this district. The experiment further indicated that North Caro- 

 lina mullet do not continue the journey to Florida, as is generally 

 supposed, but definite conclusions as to the extent of the migrations 

 must be withheld until further data are available. It is planned to 

 extend the tagging experiment another year to Florida waters. 



Material progress has been made in the study of the growth of the 

 mullet. Evidence has been gathered from a study of monthly curves 

 of length frequency, from the study of scales, and from the tagging 

 experiment. It has been found that the supposed typical North 

 Carolina stock reaches a body length of approximately 150 millimeters 

 in the first year and nearly 300 millimeters in the second. The maxi- 

 mum age is probably 5 or 6 years. Growth begins in May and extends 

 into October. Certain discrepancies in the -various data are proba- 

 bly due to the mixing of distinct racial stocks, and it is hoped that 

 these and other details may be worked out from scale studies that 

 are now under way. 



Analyses of the commercial catch at Beaufort show that the July, 

 August, and September catches consist of second-year fish (the I 

 group) and that October runs are mainly composed of either older fish 

 of the third or fourth year, which are approaching the spawning condi- 

 tion, or else of fish less than one year old (the O group). In 1924 

 the older fish (II and III groups) predominated, but in 1925 the 



