Figure 3.— Developmental stages of swordfish ova. A. 

 Developing. B. Advanced developing. C. Early ripe. D. 

 Ripe. 



sample RMO {P = 0.01) and samples RMC and 

 RPO {P = 0.05). An analysis of variance for one-way 

 design was used to test for homogeneity (Table 2). 

 The null hypothesis that the distribution of ripe ova 

 was homogeneous throughout the ovaries was re- 

 jected (P<0.05;F ratio of 5.2821 ; d.f. 17 and 3,582). 

 An examination of the means showed no general 

 trends with the different sections of each ovary and 

 locations within each section. The lack of homo- 

 geneity in ova has also been demonstrated for 

 bigeye tuna (Yuen, 1955) and albacore (Otsu and 

 Uchida, 1959). 



A further evidence of heterogeneity was indicated 

 in a comparison of ripe and early ripe ova. Table 3 

 shows the numberof ripe and early ripe ova from the 

 nine locations sampled from the right ovary. The 

 ratio of ripe to early ripe ova ranged from 0.5576 to 

 2.6792. Three samples, RPC, RPM, and RMC, had 

 almost identical ratios; but no consistent pattern was 

 evident. 



SPAWNING 



Swordfish with ovaries in a ripe condition have 

 been reported in the Mediterranean Sea off Sicily 

 (Sella, 191 1 ), in the Gulf Stream off Cuba (LaMonte, 

 1944) and in the western Pacific Ocean in the seas 

 adjacent to Minami Tori Shima located at long. 

 156°E, lat. 25°17'N(Nakamuraetal.,1951). Yabeet 

 al. ( 1959) reported the occurrence of swordfish with 

 ripe ovaries in the North Pacific Ocean in waters 

 extending from the Subtropical Convergence to the 

 equator and in the South Pacific in the Coral Sea and 

 near the Fiji Islands. Yabeetal. (1959) also reported 

 on the occurrence of seven ripe ovaries taken from 

 swordfish caught in the Indian Ocean. 



The appearance in April through July (Table 1) of 

 large swordfish in the late stages of maturity suggests 

 that the movement into coastal waters of the 

 Hawaiian archipelago may be part of a spawning 

 migration. Matsumoto and Kazama (1974) identified 

 swordfish larvae from plankton hauls taken in 

 Hawaiian waters, thus confirming the indirect evi- 

 dence based on our ovary maturation study. 

 Cavaliere (1962) reported that embryos start to form 

 in eggs with diameters between 1.60 and 1.80 mm. In 

 our samples the mean ova diameters of the most 

 advanced modes of the preserved material were 1 .20 

 mm for sample BB-2, 1.36 mm for BB-3, and 1.44 

 mm for BB-14. Ova from sample BB-14, which had 

 been immersed in seawater prior to preservation, 

 had a mean diameter of 1.57 mm. Since the gonad 



145 



