Most of the stomachs came from billfishes cap- 

 tured by vessels of the Hawaiian loiigliiie fishery. 

 Otsu (1954) and Shomura (1959) gave detailed 

 descriptions of that fishery. The catches are landed 

 at the United P'ishing Agency and the Fishing 

 Co-Op of Hawaii in Honolulu, where the fish are 

 sold at auction. The stomachs and information on 

 the date of landing, locality of capture, weight, 

 and sex for each fish were made available by the 

 fish market personnel or the purchasers of the fish. 



The vessels usually fished within sight of land. 

 Thus, most of the stomachs came from billfishes 

 captured within about 37 km. of the main Hawaiian 

 islands. A few of the stomachs, however, came 

 from billfishes caught as far as 044 km. from 

 Oahu. 



From 1902 to 1965, stomach samples were also 

 collected from billfishes captured in the Hawai- 

 ian International Billfish Tournament, held an- 

 nually since 1959 at Kona, Hawaii. The rules of 

 the tournament limited the fishing area to the lee 

 of the island of Hawaii. 



The striped marlin were 4 to 14S kg.; the size 

 distribution showed modes between 16 and 20 kg. 

 and Ijetween 36 and 40 kg. The blue marlin were 16 

 to 364 kg. ; a prominent mode was present between 

 60 and 70 kg. The shortbill spearfish were 14 to 

 38 kg.; a mode was present between 12 and 16 kg. 

 The sailfish were 14 to 38 kg. ; black marlin, from 

 36 to 290 kg. 



The stomach samples from the Honolulu mar- 

 kets were taken to the laboratory and either 

 examined immediately or preserved in 10 percent 

 Formalin^ for later examination. The samples 

 from the billfish tournaments were shipped to the 

 laboratory after preservation in 10 percent Forma- 

 lin. Ill the laboratory, the stomach contents were 

 initially sorted for tuna and tunalike specimens, 

 which were later identified to species. The tuna 

 specimens, which were affected in varying degrees 

 by digestion, could be identified by their skeletons 

 (Yabe et al., 1958; Matsumoto, 1963; Yoshida, 

 1965). 



LENGTH OF JUVENILE ALBACORE 



Few juvenile albacore from the billfish stomachs 

 were intact. To estimate the SL (.standard length) 

 of tlie fragmentary specimens, which usually in- 

 cluded part of the vertebrae, I determined the rela- 



Standard length 

 on length of : 



tion between the standard length and the lengths 

 of \-arious vertebral segments. On 21 - relatively 

 undamaged specimens (table 1) I measured the 

 standard lengt.h, lengths of the vertebral column 

 (39 vertebrae), precaudal vertebrae (lst-18th 

 vertebrae), caudal vertebrae (19th-39th verte- 

 brae), 1st to 9th vertebrae, and 19th to 2Sth verte- 

 brae. The data indicated that all the relations were 

 linear. The regressions describing the relations 

 are : 



(1) vertel)ral column, / 

 = - 0.2825 -t-1.2762L 



(s = 0.218), 



(2) pi-ecaudal vertebrae, / 



= 0.0634 -I- 2.8843L 

 (s = 0.429), 



(3) caudal vertebrae, I 



= -- 0.4370 -F2.2744L 

 (s = 0.298), 



(4) lst-9th vertebrae, I 



= 0.3200 -f6.3963L 

 (s=0.788), 



(5) 19th-28th vertebrae, I 



= - 0.4579 -H4.4282L 

 (s = 0.289), 



where I is the standard length (cm. ) , L is the length 

 (cm.) of the vertebral fragments, and s is the 

 standard deviation fr(jm regression. 



Table 1. — Measurements of standard length and various 

 vertebral column lengths of 21 juvenile albacore found in 

 stomachs of billfish caught in Pacific Ocean 



1 Trade names referred to in this publication do not imply 

 endorsement of commercial products. 



- These specimens were from stomachs of predators captured 

 not only in Hawaiian waters but in various localities in the North 

 and South Taciflc. I believe this fact should not affect the results. 

 A covariance analysis applied to the relation between standard 

 Icneth and vertebral column length for North and South Pacific 

 juvenile skipjack tuna showed no significant differences between 

 the samples in the mean vertebral column length and slope of 

 the lines. 



206 



U.S. PISH AXD WILDLIFE SERVICE 



