VON BERTALANFFY GROWTH CURVES FOR STRIPED MARLIN, 



TETRAPTURUS AUDAX, AND BLUE MARLIN, MAKAIRA NIGRICANS, 



IN THE CENTRAL NORTH PACIFIC OCEAN 



Robert A. Skillman and Marian Y. Y. Yong^ 



ABSTRACT 



The growth of striped marlin, Tetraptiirus audax, and blue marlin, Makaira nigricans, was described 

 by fitting von Bertalanffy growth curves (an assumed age model and a length-increment model) to the 

 progression of age-groups, by quarters, through the Hawaiian longline fishery from 1960 to 1970. For 

 striped marlin, the sexes grew at about the same rate and had similar predicted asymptotic maximum 

 fork lengths, 277.4-314.4 cm for males and 288.7-326.2 cm for females. For blue marlin, the sexes grew at 

 about the same rate until 250 cm. Above this length, the growth rate of males declined and an 

 asymptotic maximum length of 298.8-368.0 cm was predicted. For females above 250 cm, the growth 

 continued at a rapid rate; exhibiting little tendency toward an asymptote over the range of ages 

 available to the study. 



While blue marlin, Makaira nigricaus Lacepede, 

 are important in the U.S. sport fishery in Califor- 

 nia, Florida, and Hawaii and striped marlin, 

 Tetraptiirus audax (Philippi), are important in 

 California and Hawaii, little is known about their 

 population characteristics or parameters. In par- 

 ticular, growth of these species has received little 

 attention. In this paper, the growth of striped and 

 blue marlins is described by fitting von Ber- 

 talanffy growth curves to age-groups separated 

 from length-frequency data collected in Hawaii. 



A review of the literature revealed four papers 

 dealing with the growth of marlins. In them, 

 growth was examined by plotting the progression 

 of mean sizes for age-groups separated from 

 size-frequency data by month or some other time 

 interval; the fitting of a functional growth model 

 (e.g., von Bertalanff'y or Gompertz) was not dis- 

 cussed or attempted. Royce (1957) studied striped 

 marlin in the Hawaiian longline fishery (1949-52) 

 and concluded that small (13.6-17.7 kg) and large 

 (45.3-49.4 kg) size classes grew about 13.6 kg per 

 year. De Sylva (1957) studied the growth of 

 sailfish, IstiopJwrus platypterus (Shaw and Nod- 

 der), in the Atlantic from records obtained 

 primarily from sport catches. His growth curve, 

 fitted by eye, showed an extremely rapid rate of 

 growth: 180 cm total length in the first year of life 

 and 30 cm in the second. Maximum age was 

 estimated as IV. De Sylva and Davis (1963) com- 



pared data for the white marlin T. albidus Poey, 

 and the sailfish and concluded that white marlin 

 live longer than sailfish. Koto and Kodama (1962), 

 studying the growth of sailfish caught near Japan, 

 found an annual growth of 35 cm for a 140-175 cm 

 eye orbit-fork length group, 20 cm for a 176-195 cm 

 group, and 15 cm for a 196-210 cm group. 



The objective of this study was to quantitatively 

 describe the growth of striped and blue marlins 

 using a model that adequately followed the ob- 

 served data and provided estimates of growth 

 parameters, which could be incorporated into 

 analytical models of population dynamics. Since 

 the von Bertalanff'y growth model satisfied these 

 conditions, it was used in this study. Specifically 

 for striped marlin, growth parameters were 

 sought by sex for individual cohorts and then for 

 data pooled over all years. For blue marlin, growth 

 parameters were sought by sex only for data 

 pooled over all years because the data were in- 

 sufficient to work with individual cohorts. By 

 pooling across years, the assumption was made 

 that the populations under study were in or tend- 

 ing toward a steady state. As such, yearly varia- 

 tions in mean lengths of age-groups as well as 

 variations in growth parameters between cohorts 

 were treated as homogeneous sets of responses to 

 variations in the environment. 



MATERIALS 



'Southwest Fisheries Center Honolulu Laboratory, National 

 Marine Fisheries Service, NOAA, Honolulu, HI 96812. 



From April 1960 through April 1970 at the 



Manuscript accepted February 1976. 

 FISHERY BULLETIN: VOL. 74, NO. 3, 1976. 



553 



