BAGLIN. JR.: REPRODUCTIVE BIOLOGY OF WESTERN ATLANTIC BLUEFIN TUNA 



Table 4.— Length, weight, and gonadal data for 28 female 

 western Atlantic bluef in tuna from the Gulf of Mexico and the 

 Florida Straits collected during April, May, and June 1967, 

 1968, 1974, 1975, 1976, and 1978. The mean and standard error 

 of the mean are given at the bottom of the columns. 



'Actual weight determined 



F = -0.9057 + 0.0353 WO? = 0.81), 



where F is the number of ova >0.32 mm in 

 diameter and W is the dry weight of all eggs 

 separated from the ovarian connective tissue. 



A reduction in fecundity in older fish has been 

 reported by Bodola (1966) for gizzard shad, 

 Dorosoma cepedianum, and by Loesch and Lund 

 (1977) for blueback herring. No such decline in 

 number of eggs was found for western Atlantic 

 bluefin tuna. 



My fecundity estimates for western Atlantic 

 bluefin tuna are considerably greater than the 

 estimate given by Williamson (1962). He, 

 however, did not describe how he arrived at his 

 estimate for a western Atlantic bluefin tuna. My 

 estimates more closely agree with estimates 

 presented by Frade (1950) and Rodriguez-Roda 

 (1967) for eastern Atlantic bluefin tuna. 

 Although my estimates were based generally on 

 larger fish, it appears that western Atlantic 

 bluefin tuna are considerably more fecund than 

 eastern Atlantic bluefin tuna. 



ACKNOWLEDGMENTS 



I thank L. R. Rivas and W. J. Richards of the 

 Southeast Fisheries Center Miami Laboratory, 

 National Marine Fisheries Service, NOAA and 

 C. L. Smith of the American Museum of Natural 

 History for their many helpful comments on the 

 manuscript. I also thank the two anonymous 

 reviewers who read the manuscript and offered 

 helpful suggestions. 



LITERATURE CITED 



Baglin, R. E., Jr. 



1976. A preliminary study of the gonadal development 

 and fecundity of the western Atlantic bluefin tuna. Int. 

 Comm. Conserv. Atl. Tunas, Collect. Vol. Sci. Pap. 5 

 (SCRS-1975):279-289. 



1979. Sex composition, length-weight relationship, and 

 reproduction of the white marlin, Tetrapturus albidus, 

 in the western North Atlantic Ocean. Fish. Bull., U.S. 

 76:919-926. 



1980. Length-weight relationships of western Atlantic 

 bluefin tuna, Thunnus thynnus. Fish. Bull., U.S. 

 77:995-1,000. 



Baglin, R. E., Jr., and L. R. Rivas. 



1977. Population fecundity of western and eastern North 

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Bailey, M. M. 



1964. Age, growth, maturity, and sex composition of the 

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 Beaumariage, D. S. 



1973. Age, growth, and reproduction of king mackerel, 

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 Berrien, P. L., M. P. Fahay, A. W. Kendall, Jr., and W. G. 

 Smith. 



1978. Ichthyoplankton from the RV DOLPHIN survey of 

 Continental Shelf waters between Martha's Vineyard, 

 Massachusetts and Cape Lookout, North Carolina 1965- 

 66. Sandy Hook Lab. Northeast Fish. Cent., Natl. Mar. 

 Fish. Serv. Tech. Ser. Rep. 15, 152 p. 



Bodola, A. 



1966. Life history of the gizzard shad, Dorosoma 

 cepedianum (Lesueur), in Western Lake Erie. U.S. 

 Fish Wildl. Serv., Fish. Bull. 65:391-425. 

 Bunag, D. M. 



1956. Spawning habits of some Philippine tuna based on 

 diameter measurements of the ovarian ova. Philippine 

 J. Fish. 4:145-175. 

 Coan, A. 



1976. Length, weight, and age conversion tables for 

 Atlantic tunas. Int. Comm. Conserv. Atl. Tunas, 

 Collect. Vol. Sci. Pap. 5 (SCRS-1975):64-66. 

 Cort, J. L., C. A. Fernandez Pato, and E. De Cardenas. 

 1976. Observations sur la maturation sexuelle du thon 

 rouge, Thunnus thynnus (L.), du golfe de Gascogne. 

 Cons. Int. Explor. Mer, 6 p. 

 Erdman, D. S. 



1968. Spawning cycle, sex ratio, and weights of blue 



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