other prey in i)refereiK'e to juvenile albacore, or 

 vice versa. 



Serious error may result if my first assumi)ti()u 

 was not valid. Figure 3 shows the monthly distri- 

 bution of striped marlin, blue marlin, and short- 

 liill spearfish used in this study. These numbers 

 generally reflect the seasonal abundance of these 

 billfishes around Hawaii. Striped marlin are al- 

 niost always more abundant than blue marlin and 

 shortbill si)earfish. Seasonally, striped marlin are 

 most abundant fi'om November to June and blue 

 marlin are most abundant from June to Septem- 

 ber. Although the distribution of shortbill spear- 

 fish in figure 3 shows peaks in April and August, 

 the seasonal abundance of this species is not well 

 defined around Hawaii. Because of interspecific 

 and intraspecific dirt'crences in seasonal abundance, 

 diti'erences in catching efficiency among the billfish 

 species may affect estimates of juvenile albacore 

 abundance. Xo attempt was made to test whether 

 difl'erences did exist in catching efficiency because 

 the data were inadequate. 



The second assumption is ^Ji'obably justified; 

 studies on the food habits of billfishes indicate 

 that they are broadly carnivorous (Royce, lt).57). 



Because of the small number of juveniles, the 

 apparent abundance on a seasonal basis is shown 

 in figure -1, for all years combined. Juvenile alba- 

 coi"e occurred in billfish stomachs in all months 



except April and May ; they were most numerous 

 between August and November. The juveniles 

 were generally larger in the winter than in the 

 summer and fall. The large juveniles that were 

 collected between January and March were most 

 likely the progeny of spawning the previous 

 spring. 



My observations arc consonant with the hy- 

 pothesis of Otsu and Ucliida (1!)63) that albacore 

 .S2)end their larval and early juvenile stages in sub- 

 tropical waters and that the older juveniles then 

 migrate into temperate waters. Otsu and Uchida 

 also speculated that small albacore are probably 

 abundant generally throughout temperate waters, 

 but are not available to the commercial fisheries 

 until they are 2 or 3 years old. Occasionally, small 

 albacore (about 35 cm. TL) appear in the catches 

 of the United States west coast and Japanese pole- 

 and-line fisheries. 



No attempt was made to find difi'erences in 

 abundance among areas, for examj^le around the 

 various islands, in Hawaiian waters. It is not real- 

 istic to do so because longlinc fishing is not ran- 

 dom throughout the islands (Otsu, 1954). Because 

 billfishes are fast-moving and can probably travel 

 many miles in a single day, the location of their 

 capture may not necessarily coincide with that at 

 which they preyed on the juveniles. 



iij 



0. 



JAN. FEB. MAR APR MAY JUNE JULY AUG. SEPT OCT NOV DEC 



Figure 3. — Seasonal distribution of catches of striped marlin, blue marlin, and shortbill .spearfish off Hawaii, 1962-65. 



EARLY LIFE HISTORY AND SPAWNING OF ALBACORE IN HAWAIIAN WATERS 



209 



