FISHERY BULLETIN: VOL. 71, NO. 4 



Table 8. — Summary of major identified stomach constituents of yellowfin tuna, spotted por- 

 poise, and spinner porpoise taken from mixed-species aggregations in the eastern tropical 

 Pacific. + = present, # = important (5= 10% of volume and/or numbers). 



and completely absent as a food item of S. lon- 

 girostHs. 



Myctophidae 



At least 13 species of myctophids were identi- 

 fied from specimen stomachs. A majority of the 

 genera found (Diaphus, Diogenichthys, Cerato- 

 scopelus, Hygophum, Myctophum, Symbolo- 

 phorus, Benthosema, and Gonichthy^) are known 

 to reach the surface at night during the course 

 of vertical migrations, but most remain deep 

 during the day. A second group consisting of 

 Lepidophanes, Lampanyctus, Lobianchia, and 

 Triphoturus are usually not caught in near- 



surface waters, even at night; their migrations 

 probably do not take them as shallow as the 

 first group. Myctophids were a consistent major 

 food item of S. longirostris and occasionally 

 were common in S. attenuata. 



Gonostomatidae 



Vinciguerria is a vertical migrator found be- 

 low 200 m during the day, ranging up to sur- 

 face waters at night. Three-fourths of the full 

 stomachs of S. longirostris examined for otoliths 

 contained gonostomatid remains. In the much 

 larger sample of spotted porpoise stomachs, 

 only two contained a few gonostomatid otoliths. 



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