beginning- of one fall throug-h the following fall, 

 and grew 114 mm, 183 to 297 mm or an average 

 of 7.2 mm per month. These growth rates are 

 considei-ably faster than those estimated by 

 Richards (1968), using the Von Bertalanffy 

 (1938) growth equation. He found that females 

 292 to 312 mm grew an average of 1.6 mm per 

 month, and those 131 to 292 mm grew an average 

 of 4.5 mm per month. Our growth rates were 

 somewhat slower than the 7.5 mm per month for 

 fish in Chesapeake Bay during the first 3 years 

 of life (McHugh, 1967). 



Recoveries of fish that had been scale-sam- 

 pled when released can be used to validate aging 

 techniques described by June and Roithmayr 

 (1960). Scales from the females out 130 and 

 483 days revealed no and one new annulus, which 

 supports our aging methods. 



The best location for tag injection and time 

 required for tag incisions to heal can also be 

 determined from these recoveries. Of three lo- 

 cations selected for tag injection in adult men- 

 haden, the best appears to be about 13 mm above 

 and just forward of the origin of the pelvic fin. 

 This was inferred from sharp decreases in re- 

 coveries after 9 days of fish tagged in the other 

 locations. Tagging as little as 13 mm anteriorly 

 or posteriorly of this spot can puncture the liver 

 or spleen. Returns from two field tests designed 

 to test these three locations verified the above 

 conclusion. Returns were 11 to 50 "^f better for 

 menhaden tagged above the pelvic fin. Tag in- 

 cisions were healed in 85 ''r of the 67 fish recap- 

 tured within 10 days. The tagging scar was 

 absent in three fish recaptured within 10 days, 

 but it was still visible in one menhaden out 463 

 days. 



The information obtained from these recov- 

 eries has been worthwhile and unobtainable from 



other techniques. However, because the cost of 

 the detector-recovery system is greater than the 

 magnet recovery system and because adequately 

 precise data for population parameter estimates 

 are being obtained from tags recovered on mag- 

 nets, we are not expanding the use of the elec- 

 tronic detector-recovery system. 



LITERATURE CITED 



BERTALANFFY, L. VON. 



1938. A quantitative theory of organic growth. II. 

 Inquiries on growth laws. Hum. Biol. 10: 181-213. 

 DAHLGREN, E. H. 



1936. Further developments in the tagging of the 

 Pacific herring, Clupea pallasii. J. Cons. 11: 

 229-247. 



HART, J. L., and A. L. TESTER. 



1937. The tagging of herring (Clupea pallasii) 

 in British Columbia : methods, apparatus, inser- 

 tions, and recoveries during 1936-37. Br. Colum- 

 bia Prov. Fish. Dep., Report for the year ended 

 December 31st, 1936, p. R.55-R67. 



JEFFERTS, K. B., P. K. BERGMAN, and 

 H. F. FISCUS. 



1963. A coded wire identification system for macro- 

 organisms. Nature 198: 460-462. 

 JUNE, F. C, and C. M. ROITHMAYR. 



1960. Determining age of Atlantic menhaden from 

 their .scales. U.S. Fish Wildl. Serv., Fish Bull. 

 60: 323-342. 

 McHUGH, J. L. 



1967. Estuarine nekton. In G. H. Lauff (editor). 

 Estuaries, p. 581-620. Amer. Assoc. Adv. Sci., 

 Washington. 



REINTJES, J. W. 



1963. An initial inquiry into a photoelectric device 

 to detect menhaden marked with fluorescent pig- 

 ments. Int. Comm. Northwest Atl. Fish., Spec. 

 Publ. 4: .362-368. 



RICHARDS, C. E. 



1968. Analog computer techniques for age-growth 

 studies of fish. Proc. Southeast Assoc. Game 

 Fish Comm., 21st Annu. Conf. 1967: 273-275. 



