Hence, we had additional confidence in our in- 

 terpretation of the ridges as annual events and 

 since ridges were easier to count, we used them in 

 our age determinations. Further analysis might 

 show daily increments (Pannella 1974) within the 

 lunar increments. 



In conclusion, we have been able to collect the 

 otoliths of sailfish, and all three otoliths showed 

 morphological features that can be readily ob- 

 served. The internal and external otolith struc- 

 tures, viewed with SEM, appeared to show an an- 

 nual periodicity and provided data that are not 

 available by other means. With this data it is pos- 

 sible to determine a growth rate and age estimate 

 for all sizes of the sailfish sampled, including 

 larger fish that were difficult to age in the past. 



Acknowledgments 



We wish to thank Vern Barber and the Scanning 

 Electron Microscope Laboratory at Memorial 

 University, St. John's, Newfoundland, Canada, for 

 the use of the SEM and help in specimen prepara- 

 tions. We thank J. T. Reese Company, Ft. Lauder- 

 dale, Fla., and the Pflueger Taxidermy Co., Hal- 

 landale, Fla., who made the fish available, for 

 their generosity and assistance. Without their 

 cooperation, this study would not have been possi- 

 ble. We appreciate the support of R. Macon and R. 

 Feller's constructive comments on the manuscript 

 and his assistance with the statistical analysis. 

 This work was supported by a Visiting Fellowship 

 from the National Research Council of Canada to 

 the senior author and a grant from the Research 

 and Productive Scholarship Fund of the Univer- 

 sity of South Carolina to J. M. Dean. 



Literature Cited 



BAGENAL, T. B. (editor). 



1974. Proceedings of an International Symposium on the 

 Ageing of Fish. Unwin Brothers, Surrey, Engl., 234 p. 



Beckett, j. s. 



1974. Biology of swordfish, Xiphias gladius L., in the 

 northwest Atlantic Ocean. In R. S. Shomura and F. Wil- 

 liams (editors), Proceedings of the International Billfish 

 Sympo.sium, Kaila-Kona, Hawaii, 9-12 August 1972. Part 

 2. Review and contributed papers, p. 103-106. U.S. Dep. 

 Commer., NOAA Tech. Rep. NMFS SSRF-675. 

 DEGENS, E. T. W. G. DEUSER, AND R. L. HAEDRICH. 



1969. Molecular structure and composition of fish oto- 

 liths. Mar. Biol. (Berl.) 2:105-113. 

 DE SYLVA, D. P 



1957. Studies on the age and growth of the Atlantic sail- 

 fish, Istiophorus americanus (Cuvier), using length- 

 frequency curves. Bull. Mar. Sci. Gulf Caribb. 7:1-20. 



1969. Ti-ends in marine sport fisheries research. Trans. 

 Am. Fish. Soc. 98:151-169, 

 HECHT. T 



1978. A descriptive systematic study of the otoliths of the 

 neopterygean marine fishes of South Africa. Part 1. Intro- 

 duction. Trans. R. Soc. S. Afr. 43:191-197. 



IRIE, T 



1955. The crystal texture of the otolith of a marine teleost 

 Pseudosciaena. J. Fac. Fish. Anim. Husb. Hiroshima 

 Univ 1:1-13. 

 JOLLEY, J. W, Jr. 



1974. On the biology of Florida east coast .Atlantic sailfish, 

 ihtiophorus platypterus). In R. S. Shomura and F. Wil- 

 liams (editors). Proceedings of the International Billfish 

 Symposium, Kailua-Kona, Hawaii, 9-12 August 1972. 

 Part 2. Review and contributed papers, p. 81-88. U.S. Dep. 

 Commer., NOAA Tech. Rep. NMFS SSRF-675. 



1977. The biology and fishery of Atlantic sailfish. /.s- 

 tiophorus p/atypteriin, from southeast Florida. Fla. Mar. 

 Res. Publ.28,31p. 



Koto, T, and K. Kodama. 



1962. Some considerations on the growth of marlins, using 

 size-frequencies in commercial catches. I. Attempts to es- 

 timate the growth of sailfish. |In Jpn., Engl. 

 summ.] Rep. Nankai Reg. Fish. Res. Lab. 15:97-108. 



LOWENSTEIN. O. 



1971. The labyrinth. In W. S. Hoar and D. J. Randall 

 (editors). Fish physiology. Vol. V, p. 207-240. Acad. Press, 



N.Y. 



MAKSIMOV, V. R 



1971. The biology of the sailfish [Istiophorus platypterus 

 (Shaw et Hodder)] in the Atlantic Ocean. J. Ichthyol. 

 11:850-855. 



Mather, F J., Ill, D. C. Tabb, J. M. Mason, Jr., and H. L. 

 Clark. 



1974. Results of sailfish tagging in the western North At- 

 lantic Ocean. In R. S. Shomura and F Williams (editors). 

 Proceedings of the Inte'^national Billfish Symposium, 

 Kailua-Kona, Hawaii, 9-12 August 1972. Part 2. Review 

 and contributed papers, p. 194-210. U.S. Dep. Commer.. 

 NOAA Tech. Rep. NMFS SSRF-675. 



Morrow, J. E. 



1979. Preliminary keys to otoliths of some adult fishes of 

 the Gulf of Alaska, Bering Sea, and Beaufort Sea. U.S. 

 Dep. Commer., NOAA Tech. Rep. NMFS CIRC-420, 32 p. 



Pannella, G. 



1974. Otolith growth patterns: an aid in age determination 

 in temperate and tropical fishes. In T. B. Bagenal 

 (editor). Proceedings of an International Symposium on 

 the Ageing of Fish, p. 28-39. Unwin Brothers. Surrey, 

 Engl. 



SIX. l. d., and h. e horton. 



1977. Analysis of age determination methods for yellow- 

 tail rockfish, canary rockfish, and black rockfish off Ore- 

 gon. Fi.sh. Bull., U.S. 75:405-414. 

 WAT.S0N, J. E. 



1964. Determining the age of young herring from their 

 otoliths. Trans. Am. Fish. Soc. 93:11-20. 



RICHARD L. RADTKE 



Department of Fisheries and Oceans 

 St. John's, Newfoundland. Canada 



366 



