&'Jc or greater and were used for estimating fecun- 

 dity. The mean GSI showed that ovarian weights 

 were lowest during October and increased from 

 November through May (Figure 6). The mean GSI 

 of 2.6 for April and May is lower than the 4.5 mean 

 GSI found by Krumholz (1958) for late April. The 

 GSI of 9.3 (Table 3) agrees with the highest GSI of 

 9.76 found by Krumholz. The high mean GSI val- 

 ues determined by me for April and May, with the 

 sudden decrease in June, indicated that spawning 

 probably occurred during April and May (Figure 

 6). Therefore, only one spawning season per year 

 was indicated for the Florida Straits. 



White marlin may also spawn in other areas. 

 One fish captured in April 1976 in the Windward 

 Passage had ripe eggs measuring 1.16 mm. Hayasi 

 et al. (1970) found white marlin with mature 

 gonads during April-June in the northern Carib- 

 bean. Erdman (1956) found well-developed 



Figure 6. — Seasonal variation of mean gonosomatic index in 

 186 white marlin collected from 1972 to 1976 (number offish 

 indicated above histograms). 



Table 3.— Weight, length, and gonadal data for 12 female white 

 marlin from the Florida Straits collected during 1972, 1974, and 

 1975. The mean and standard error of the mean are given at the 

 bottom of the columns. 



Estimated number of eggs 



Body 



weigtit 



(kg) 



Body 

 lengthi 

 (cm) 



Ovary 

 wet weight 



(g) 



Gono- 

 somatic 

 index 



0,55 mm in 



diameter 



(millions) 



■0,29 mm in 



diameter' 



(millions) 



'Estimated using actual percent from 30 to 55 mm in diameter from 25 

 eggs measured for each fish. 

 2Entire ovaries available. 



ovaries in white marlin caught off Puerto Rico in 

 April and found well-formed eggs in a fish taken in 

 June from the same locality. 



The smallest fish approaching a ripe condition 

 with large ovaries weighed 26.8 kg (Table 3). 

 Ueyanagi et al. ( 1970) reported that white marlin 

 reach sexual maturity at 130 cm eye-fork length. 

 Using the conversion equation of Lenarz and 

 Nakamura (1974), 130 cm eye-fork length would 

 be equal to about 20.3 kg. 



Frequency distributions of white marlin ovum 

 diameters were made from measurements on 

 3,912 ova from spent, partly spent, and mature 

 fish (Figure 7). Spent fish caught during May and 

 June contained mostly eggs 0.15 mm in diameter 

 and smaller. Eggs from a partly spent fish caught 

 during June had a frequency mode of about 0.35 

 mm, with few eggs larger than 0.60 mm. Some of 

 the larger eggs appeared to be undergoing absorp- 

 tion. Jolley ( 1977), in his histological examination 

 of spent sailfish, found degeneration and absorp- 

 tion of advanced unovulated eggs common. Mer- 

 rett (1970), studying several species of billfish 

 from the Indian Ocean, suggested that there also 

 may be at least a partial resorption of resting 



5 



o 



S300 

 Z 250- 



150- 

 100- 

 50 



1 



0.05 



15 0.25 0.35 



045 55 65 75 85 95 105 

 DIAMETER (mm) 



1 



1.15 



Figure 7. — Frequency distribution of white marlin ovum 

 diameters for: A, four spent fish (827 ova) in May and June; B, 

 one partially spent fish (406 ova) in June; C, one mature fish (2, 

 679 ova) in April. 



924 



