294 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Table 6. — Field observations on sex and maturity of large 

 albacore (over 90 cm.) taken on longline during POFI 

 cruises to the North Pacific ' 



Date of 

 capture 



Jan. 22, 1954. 



Jan. 27 



Do 



Do 



Do 



Do... 



Do 



Do. . 



Do 



Do 



Do.. 



Do 



Do 



Do 



Jan. 28 



Oct. 24 



Dec. 9 



Do 



Dec. 12 



Do 



Dec. 14 



Do.... 

 Do... 



.lan. 17, 1955. 



Jan. 18 



Do 



Jan. 20 



Jan. 28 



Do 30°42' N 



Position of capture 



Latitude Longitude 



26°28' N. 

 33°58' N. 

 33°58' N. 

 33°58' N. 

 33°58' N. 

 33°58' N. 

 33°58' N. 

 33°58' N. 

 33°58' N. 

 33°58' N. 

 33°58' N. 

 33°58' N. 

 33°58' N. 

 33°58' N. 

 35°27' N. 

 38°40' N. 

 34°23' N. 

 34°23' N. 

 36°14' N. 

 36°14' N. 

 35°35' N. 

 35°35' N. 

 35°35' N. 

 33°50' N. 

 35°48' N. 

 35°48' N. 

 31°25' N. 

 30°42' N. 



159°39' W. 

 159°44' W. 

 159°44' W. 

 ]59°44' W. 

 159°44' W. 

 159°44' W. 

 159°44' W. 

 159°44' W. 

 159°44' W. 

 159°44' W. 

 159°44' W. 

 159°44' W. 

 159°44' W. 

 159°44' W. 

 15S°38' W. 

 175°27' W. 

 159°48' W. 

 159°48' W. 

 159°55' W. 

 159°55' W. 

 1.W21' W. 

 158°21' W. 

 158°21' W. 

 179°44' W. 

 179°49' W. 

 179°49' W. 

 17S lis' W. 

 175°01' W. 



175°01' W. 



Description of 

 gonad condition 



Immature. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 

 Recovering. 

 Immature. 

 Spawned-out. 

 Spent- 

 Immature. 



Do. 



Do. 

 Spent. 

 Immature. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 

 Some milt in 



testes. 2 

 No milt in testes. 



1 Includes only those observations in which both sex and gonad condition 

 were recorded. 



2 The presence of milt in the testes does not necessarily indicate advanced 

 maturity, as male albacore taken in tropical and subtropical waters almost 

 invariahly contain some milt in testes regardless of the degree of sexual 

 maturity, 



who examined histologically a series of male and 

 female gonads, concluded that the British Col- 

 umbia fishery is dependent on immature fish. 



Brock (1943) recorded a range in egg diameters of 

 0.01 to 0.1 mm. in Oregon albacore. He reported 

 that "fish with ripening ova are not present in 

 the Oregon fishery and have never been recorded 

 from the California fishery." Kishinouye (1923) 

 found no fish with maturing reproductive elements 

 in Japanese waters. According to Suda (1954), 

 albacore captured west of Midway Islands, north 

 of the Subtropical Convergence, are all extremely 

 immature, with gonad weights below 50 grams for 

 both males and females. Thus, the albacore 

 resource which furnishes the basis for the spring 

 live-bait fishery in Japanese coastal waters and 

 the Japanese winter longline fishery in midocean, 

 as well as the American west coast fishery in the 

 summer, is composed either of sexually immature 

 fish, or of adult fish which show no signs of gonad 

 development beyond the early developing stage. 

 The implications are, therefore, that albacore do 

 not spawn in the temperate waters of the North 

 Pacific. 



HAWAIIAN ISLANDS 



Because of the great predominance of males In 

 the landings of albacore in the Hawaiian Islands 

 (fig. 7), coupled with the small numbers taken, 

 we had hoped initially to utilize both male and 

 female gonads in this study. We found, however, 

 that the presence or absence of milt is not a 



O 10 

 or 



"i i i — i — r 



1955 



m\ a I 



1 r 



il 



n — i — i i i — r 



I J II.. 



"i i i r 



i — r-r 



t--t — r 



MALES 

 FEMALES 



I 



 I , /'■ ' 



1956 



i niil t.iiliii.iiBii jl.H.iif]i J i'- 1 I;  imiJib ibh ii J I J I J J I J ii 



>i— L 



92 94 96 98 100 102 104 106 108 IIO 112 114 116 118 120 122 



FISH LENGTH (CM ) 



Figure 7. — Size and sex distribution of albacore sampled from landings in the Hawaiian Islands, (a) 1955 (b) 1956. 



