(Furukawa et al., 1958). The condition factor also 

 showed a seasonal drop from about 10.8 in December 

 to about 8.7 in June for fish of body length 166-195 

 cm. The drop in condition factor before June was 

 much more abrupt than the increase after June. A 

 similar seasonal cycle was also apparent for fish of 

 136-165 cm. 



3.44 Metabolism 



There are no data on metabolic rates for this 

 species. Lindsey (1968) found body muscle 

 temperatures as much as 2.6°C higher than the sur- 

 rounding seawater. The highest temperature recorded 

 occurred near the center of the epaxial muscle mass 

 with a lesser maximum slightly below the hypaxial 

 muscle mass center. Red muscle was found to be lower 

 than white muscle at comparable depths beneath the 

 skin. Temperatures of the viscera exceeded seawater 

 temperatures by 0.7-1.3°C. 



Barrett and Williams (1965) report the mean 

 hemoglobin content in 16 striped marlin was 11.3 ± 

 0.75 g Hb/100 ml and ranged from 5.8 to 16.8. 



3.5 Behavior 



For feeding behavior, see 3.41; for reproductive 

 behavior see 3.13, 3.21. 



3.51 Migrations and local movements 



See also 2.22 and 2.3. 



The migration pattern of striped marlin appears to 

 be principally a simple latitudinal movement between 

 spawning areas and productive feeding areas (Parin, 

 1968). The movement is toward higher latitudes in the 

 summer of each hemisphere and back toward 

 equatorial waters in winter. In the northern 

 hemisphere the peak of the northward migration is 

 August-September and the southward migration 

 begins in October and continues through February. 

 The northward movement is also accompanied by an 

 eastward expansion in the eastern Pacific (Howard 

 and Ueyanagi, 1965; Fisheries Agency of Japan, 

 Research Division, 1969-72). 



In the central North Pacific small fish of about 13.6 

 kg (30 pounds) appear in Hawaii in winter, grow to 

 22.7-27.2 kg (50-60 pounds) by May or June, then 

 migrate north for several months, and return to 

 Hawaii as larger fish the next year. A similar pattern 

 of migration is common to areas west of long. 180° 

 (Howard and Ueyanagi, 1965). 



In the southern hemisphere west of long. 150°W fish 

 migrate north from south of lat. 30° S from August 

 through November and form concentrations which are 

 exploited in the area lat. 18°-19°S. The period of this 

 migration corresponds to the spawning season. After 

 November the fish appear to migrate south (Koga, 

 1967). 



In the eastern South Pacific a high density area, 



which occurs in the area lat. 10°-17°S, long. 90°- 

 115°W during the second and third quarters, appears 

 to move southwest to the region of lat. 20°-28°S, long. 

 100°-110°W in the fourth and first quarters (Kume 

 and Joseph, 1969a, b). 



In the eastern North Pacific the seasonal north- 

 south movements are apparent but less pronounced. 

 Striped marlin do occur in their extreme northern 

 range (southern California) during late summer and 

 fall when surface temperatures reach a peak, but it is 

 not clear whether these fish have come from the south 

 or from the west (Howard and Ueyanagi, 1965). Data 

 from fish tagged in the sport fisheries of southern 

 California and Mexico provide evidence that striped 

 marlin are capable of fairly long migratory 

 movements up to 3,000 miles (Fig. 7). Some fish do 

 move from California southward to the tip of Baja 

 California and further, but there is no evidence of 

 migration from Mexican waters to southern California 

 (Squire, 1974). 



Howard and Ueyanagi (1965) suggested on the basis 

 of the appearance of an unusually small size group in 

 California in 1958 and subsequent appearance 2 yr 

 later of a small group in New Zealand, which was of a 

 size expected for fish 2 yr older than the former, that 

 there may be transpacific interchange between these 

 remote areas. 



Following the 1954 hydrogen bomb test in Bikini, 

 contaminated fish were found only from the North 

 Pacific, suggesting the possibility of separate pop- 

 ulations in the two hemispheres (Nakamura, 

 1969). 



In addition to the primary migratory trend, there 

 are also lesser local movements reported. The area of 

 high density off the central Mexican coast generally 

 tends to expand westward seasonally reaching its 

 maximum westward extent at about long. 130°W dur- 

 ing the fourth quarter of the year (Kume and Joseph, 

 1969a, b). The region of high density around the 

 Galapagos Islands during the second and third 

 quarters expands eastward to the coast of Ecuador 

 during the fourth and first quarters (Kume and 

 Joseph, 1969a, b; Kume and Schaefer, 1966). 



Nakamura (1949) mentions dense schools move 

 from south to north along the coast of Vietnam in 

 March and April. 



In the western Pacific, Furukawa et al. (1958) 

 report a gradual westward migration of fish from the 

 vicinity of the Bonin Islands to the East China Sea in 

 July and August where they stay until November 

 after which a southward emigration takes place. 



Migratory patterns in the Indian Ocean are un- 

 known. The seasonal increase in density off East 

 Africa during the northeast monsoon is believed to be 

 a postspawning feeding migration (Williams, 1967; 

 Merrett, 1971). The north-south type of seasonal 

 movements that are typical in the Pacific are most 

 evident off South Africa. A northward movement in 

 the springtime (second quarter) is evident in the 



147 



