data set. The sexual dimorphism in length that has 

 been noted by many workers (e.g., Strasburg, 1970) 

 apparently extends to the weight-length relationship 

 also. That is, females not only grow to a greater 

 length than males, but are proportionally heavier at 

 the same length. 



For striped marlin, analysis of the pooled data 

 produced an estimate of the coefficient of allometry 

 that appears to be greater than isometry. Inability 

 to divide the data by sex was unfortunate since it is 

 not known whether sexually dimorphic growth 

 characteristics exist for the striped marlin. If such 

 an effect does exist, it is believed to be less marked 

 than in the blue marlin. Hence, the largeness of the 

 striped marlin coefficient relative to that for the 

 blue marlin, for both pooled and female data alone, 

 probably was not due to sexual dimorphism. 



There are only two papers in the literature giving 

 weight-length relationships that may be compared 

 to ours, since the data used by Royce (1957) were 

 included in this analysis. De Sylva (1957) presented 

 a length-weight plot for sailfish from the Atlantic 

 Ocean, but a model was not fitted to the data. A fish 

 approximately 250 cm FL would weigh 34 kg 

 whereas our study predicts 37 kg. Kume and Joseph 

 (1969) fitted the log-linear model to blue marlin, 

 sailfish, shortbill spearfish, striped marlin, and 

 swordfish data. The coefficients of allometry and 

 the intercept points from their calculations are pre- 

 sented in Table 4 for direct comparison to those 

 from this study. For all species, the coefficients of 

 allometry for fish from the central Pacific were 

 greater than those from the eastern tropical Pacific. 

 If the coefficients were shown to be statistically 

 different, there would be little point in comparing 

 the intercept values since the relationships would 

 already have been shown to be different. However, 

 since the intercept value is related to the coefficient 

 of condition, it should be noted that all of the inter- 

 cept values for the central Pacific fish were smaller 

 than those for the eastern tropical Pacific fish by a 

 factor of 10. These differences may not be real be- 

 cause the samples for the central Pacific contained 

 larger individuals than did the samples for the east- 

 ern tropical Pacific. 



LITERATURE CITED 



BROWN, B.E., and R.C. HENNEMUTH. 



1971. Length-weight relations of haddock from commercial 

 landings in New England, 1931-55. U.S. Dep. Commer., 

 NOAA Tech. Rep. NMFS SSRF-638, 13 p. 

 DE SYLVA, D. P. 



1957. Studies on the age and growth of the Atlantic sailfish, 

 Istiophorus americanus (Cuvier), using length-frequency 

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

 DRAPER, N.R., and H. SMITH. 



1966. Applied regression analysis. John Wiley Sons, N.Y., 

 407 p. 

 GLASS, N.R. 



1969. Discussion of calculation of power function with spe- 

 cial reference to respiratory metabolism in fish. J. Fish. 

 Res. Board Can. 26:2643-2650. 

 HAFLEY, W.L. 



1969. Calculation and miscalculation of the allometric equa- 

 tion reconsidered. BioScience 19:974-975, 983. 

 HUXLEY, J.S., and G. TEISSIER. 



1936. Terminology of relative growth. Nature (Lond.) 

 137:780-781. 

 KUME, S., and J. JOSEPH. 



1969. Size composition and sexual maturity of billfish caught 

 by the Japanese longline fishery in the Pacific Ocean east 

 of 130°W. [In Engl.] Bull. Far Seas Fish. Res. Lab. 

 (Shimizu), 2:115-162. 

 LECREN, E.D. 



1951. The length- weight relationship and seasonal cycle in 

 gonad weight and condition in the perch (Perca 

 fluviatilis). J. Anim. Ecol. 20:201-219. 

 MADANSKY, A. 



1959. The fitting of straight lines when both variables are 

 subject to error. J. Am. Stat. Assoc. 54:173-205. 



PIENAAR, L.V., and J.A. THOMSON. 



1969. Allometric weight-length regression model. J. Fish. 

 Res. Board Can. 26:123-131. 



ROYCE, W.F. 



1957. Observations on the spearfishes of the central Pacific. 

 U.S. Fish Wildl. Serv., Fish. Bull. 57:497-554. 

 STEEL. R.G.D., and J.H. TORRIE. 



1960. Principles and procedures of statistics with special 

 reference to the biological sciences. McGraw-Hill, N.Y., 

 481 p. 



STRASBURG, D.W. 



1970. A report on the billfishes of the central Pacific Ocean. 

 Bull. Mar. Sci. 20:575-604. 



TESCH. F.W. 



1968. Age and growth. In W.E. Ricker (editor), Methods for 

 assessment offish production in fresh waters, p. 93-123. 

 International Biological Programme Handbook 3. Black- 

 well Sci. Publ., Oxford. 



137 



