BECKER: PARAMETERS OF JUVENILE CHINOOK SALMON 



Table I. — Organisms consumed by juvenile chinook salmon (0-age group) in the central Columbia River. 



examined in 1968 and 769 fish in 1969.) 



(435 fish 



1968' 



1969 



Food organism 



Number 



Number 



1968' 



1969 



Food organism 



Number 



Number 



/o 



Dipfera: 

 Adults: 



Chironomidae- 



Dolichopodidoe 



Empididae 



Simuliidae 



Culicidae 



Ephydridae 



Heieidoe 



Stratiomyidoe 



Dixidae 



Unidentified 

 Larvae: 



Chironomidae 



Dolichopodidoe 



Empididae 



Simuliidae 



Ephydridae 



Heleidae 



Muscidae 



Unidentified 

 Pupae: 



Chironomidae 



Tipulidae 



Heleidae 



Unidentified 



Total Diptera 



Hemiptero: 

 Notonecfidae 

 Mesoveliidae 

 Macroveliidae 

 Corixidae 

 Saldidae 

 Hebridae 

 Unidentified 



Total Hemiptero 



Coleoptera: 

 Adults: 



Unidentified 

 Larvae: 



Dytiscidae 



Noteridae 



Hydrophilidoe 



Elmidae 



Ptilodactylidae 



Unidentified 



Total Coleoptera 



Lepidoptero: 



Unidentified adults'* 

 Unidentified larvae'* 



Total Lepidoptero 



300 



34 



3 

 



3.2 



0.0 



0.4 

 0.0 

 0.0 



1 1 ,062 

 6 

 4 

 52 

 6 

 3 

 1 

 1 

 1 

 193 



3,450 



4 



1 



54 



1 





 

 9 



18 

 

 2 

 4 



14,872 



918 

 2 

 

 1 



8 







27 



956 



58.2 

 30.0 

 0.0 

 0.3 

 0.0 

 0.0 

 0.0 

 0.0 

 0.0 

 1.0 



18.1 

 0.0 

 0.0 

 0.3 

 0.0 



0.0 



0.1 



0.0 

 0.0 



78.3 



4.8 

 0.0 



0.0 

 0.0 



0.1 

 5.0 



Trichoptera: 

 Adults: 



Hydropsychidae 

 Psychomyiidae 

 Calamoceratidae 

 Hydroptilidae 

 Unidentified 

 Larvae: 



Hydropsychidae 



Psychomiidae 



Phryganeidae 



Rhyacophilidae 



Unidentified 



Total Trichoptera 



Ephemeroptera: 

 Subimagos: 



Unidentified 

 Nymphs: 



Baetidoe 



Unidentified 



Total Ephemeroptera 



Hymenoptera: 



Unidentified adults 



Homoptera: 

 Adults: 

 Aphididae 

 Aleyrodidae 

 Unidentified 



Total Homoptera 



Collembolo: 



Hypogastruridae 



Other insects: 

 Thysanoptera 

 Megaloptero 

 Unidentified adults 

 Unidentified larvae 

 Unidentified 



Total other insects 



Total insects 



Other food items: 

 Fish larvae 

 Acori 



Zooplankton 

 Algae 

 Arachnida 

 Plant seeds 



Total other food items 



115 



1.2 



,140 



974 



6.0 



5.1 



405 



4.3 



300 



1.6 



208 



1.1 



' 1968 data from Becker (1970a). 



2 Primarily emerging subadults. 



3 Less than 0.05%. 



■» Primarily Parar^yractic sp. (Pyralidae). 



5 Number of fish containing small quantities of Cladocera, Ostracoda, Copepodo, or Amphipoda. 



^ A quantity of Anacystis. 



391 



