Female: 



Ueyanagi et al. (1970, Fig. 27) showed that the 

 percentage group maturity of female white marlin 

 caught in the area east of Brazil in November-March 

 increased with size of fish. 



No information on the fecundity or number of eggs 

 produced in a year was found. 



There is no direct information on the number of 

 broods produced during a lifetime, but two white 

 marlin tagged as adults have been recaptured about 6 

 yr after their release [unpublished WHOI (Woods 

 Hole Oceanographic Institution) data]. This indicates 

 that a white marlin might spawn at least six times in 

 its lifetime. 



No information was found on variation in fecundity 

 with health or condition, or on correlation between the 

 number of spawn or young produced and the nature of 

 the environment. 



3.16 Spawning 



The available information indicates that white 

 marlin spawn once a year (de Sylva and Davis, 1963; 

 Hayasi et al., 1970; Ueyanagi et al, 1970). Knowledge 

 of spawning seasons, areas, and behavior is in- 

 complete, because of difficulties in identifying larvae, 

 and the lack of continuous and comprehensive gonad 

 studies. The known distribution of larvae and 

 juveniles is described in 2.21. Ueyanagi et al. state 

 that spawning occurs in subtropical waters and is at 

 its peak in early summer. In their plot of percentage 

 group maturity of female white marlin by areas and 

 quarters of the year, Ueyanagi et al. (1970, Fig. 20) 

 show that the only area in the South Atlantic with a 

 concentration of maturing fish is the one between lat. 

 20°S and 30°S and long. 20°W and the South 

 American coast. In the fourth quarter of the year, 77% 

 of 51 fish examined in the part of this area west of 

 long. 40°W and 95% of 736 examined in the part east 

 of that meridian were maturing. In the first quarter, 

 89% of those examined in both parts of the area (94 in 

 the west and 77 in the east) were maturing. Their 

 studies of maturity of females in the area east of 

 Brazil showed a decrease in the number of maturing 

 fish and an increase in the number of spawned-out 

 fish from November through January (Ueyanagi et 

 al., 1970, Fig. 23). Hayasi et al. (1970) note that the 

 rise in hooking rate off southern Brazil in November- 

 April is associated with the appearance of large fish, 

 presumably spawners, in the area, and that the ac- 

 curacy of this assumption was demonstrated by the 

 appearance of postlarvae and juveniles in the area. 



They also state that the white marlin taken west of . 

 long. 25°W were spawners, whereas those taken east 

 of there were feeding fish. 



The same authors mention that white marlin 

 caught in the Caribbean in winter had un- 

 derdeveloped gonads, but that adults with matured 

 gonads were caught in the northern Caribbean in 

 April-June. These findings are in accord with Erd- 

 man's (1956) statements that the ovaries of white 

 marlin taken off Puerto Rico were enlarged in April 

 and that the best formed eggs he had seen were in a 

 fish taken there on 9 June. They also fit with de Sylva 

 and Davis' (1963) report of nearly ripe females in the 

 eastern Straits of Florida in March and May and 

 Krumholz's (1958) finding of nearly ripe males in the 

 same area in late April. De Sylva and Davis found 

 that the ovaries of females taken off Cape Hatteras in 

 June and off Maryland and southern New Jersey in 

 summer were in postspawning or resting condition, 

 although many of the males were still ripe. It is 

 generally believed that summer concentrations of 

 white marlin in the Gulf of Mexico and between Cape 

 Hatteras and Cape Cod are of spent fish which are in- 

 tent on feeding. These findings suggest that spawning 

 in the western North Atlantic occurs almost entirely 

 in spring, in the areas noted here and under 2.21. 



The spawning period and areas coincide at least in 

 part, with those of the western Atlantic bluefin tuna, 

 Thunnus thynnus thynnus (Rivas, 1955; Potthoff and 

 Richards, 1970). The young of this species share their 

 summering area between Cape Hatteras and Cape 

 Cod with the white marlin. 



The spawning areas of white marlin are in deep and 

 blue oceanic waters with generally high surface 

 temperatures (20°-29°C, except in the Atlantic 

 southern gyrals, reg. 5.9.1), and high surface salinities 

 (=-35%o). Except off Cabo Frio, Brazil, the produc- 

 tivity of these waters is considered to be low. 



Nothing was found in the literature about the 

 variations of spawning grounds. 



Little is known of the ratios and distribution of sex- 

 es on the spawning grounds. Ueyanagi et al. (1970) 

 found 2,037 males and 1,051 females in the area 

 between lat. 5°S and 30°S, and long. 15°W and the 

 coast of South America, during November- April. This 

 area includes the South Atlantic spawning ground 

 described above (lat. 20°S-30°S, long. 20°W to the 

 coast), and the period coincides with the spawning 

 season as indicated by Hayasi et al. (1970). In late 

 April, Krumholz (1958) found 20 males and 22 

 females in the eastern Straits of Florida. 



Hemingway (1935) described the breeding of white 

 marlin as follows: "White marlins breed off Cuba in 

 May. They breed in the same way that the grouper 

 does, except that as they are a fish of the current, they 

 breed in the current instead of on the reef. The female 

 marlin heads into the current while the male heads in 

 the opposite direction, and while they are side by side 

 the female expels the eggs and the male the milt; the 



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