combined) . The source of data for the net hauls is 

 table 3 of this paper; the sources for the tuna 

 stomach contents are various tables by Alverson 

 (1963a). 



Each of the tables 8 to 14 shows the percentage 

 composition of fish, crustaceans, and cephalopods 

 in material caught by the 1.5-m. net, by yellowfin 

 tuna, and by skipjack tuna, respectively, for a par- 

 ticular area. Each of the three main categories is 

 then further divided into components (generally 

 families), of which each accounted for at least 

 0.5 percent by volume of the total material (from 

 1.5-m. net, yellowfin tuna, or skipjack tuna), for 

 the area ; other components ( including material not 

 identified to family) were lumped. The percent- 

 ages in tables 12 and 14 for skipjack tuna differ 

 slightly from the corresponding percentages in 

 Alverson's tables, because he included small 

 amoimts of materials from stomachs of skipjack 

 tuna (1.5 percent in area 5 ; 0.3 percent in areas 11 

 and 12) which are not regarded as micronekton. 

 Alverson separated Thimnidae from Katsuwoni- 

 dae in the fish families represented in his material, 

 but they are here combined as Thimnidae, and 

 have been so entered in table 3 and tables 8 to 14. 

 Volumes for groups of animals in tables 8 to 14 

 include all ontogenetic stages unless otherwise 

 stated. 



Table 8. — Percentage taionomic composition of micronekton 

 in area 1 of figure 5, from net hauls and tuna stomachs 



(21 standard night net hauls of 1.5-m. net (18,971 ml.); 567 stomachs of 

 yellowfin tuna (37,489 ml.); 151 stomachs of skipjack tuna (4,661 ml.): 

 asterisk means <0.05 percent) 



Table 9. — Percentage taxonomic composition of micro- 

 nekton in area 2 of figure 6, from net hauls and tuna 

 stomachs 



[6 standard night net hauls of 1.5-m. net (827 ml.); 328 stomachs of yellowfin 

 tuna (62,225 ml.); 48 stomachs of skipjack tuna (1,862 ml.); asterisk means 

 <0.05 percent] 



Table 10. — Percentage taxonomic composition of micronek- 

 ton in area S of figure 5, from net hauls and tuna stomachs 



(18 standard night net hauls of 1.5-m. net (3,836 ml.); 155 stomachs of yellowfin 

 tuna (12,062 ml.); 5 stomachs of skipjack tuna (247 ml.); asterisk means 

 <0.05 percent) 



MICROXEKTON OF THE EASTERN TROPICAL PACIFIC OCEAN 



103 



