FISHERY BULLETIN: VOL. 80, NO. 1 



formation about this species. Second, for most 

 species of euphausiids and many copepods, chae- 

 tognaths, and pteropods in our collections, we 

 have no evidence that differential day/night 

 avoidance is taking place. Therefore, for many 

 ecological studies of oceanic zooplankton, nets 

 still seem the most effective tool to use to quanti- 

 tatively collect them. 



ACKNOWLEDGMENTS 



We gratefully acknowledge the assistance 

 given us by R. Backus and J. Craddock in work- 

 ing up the MOCNESS 10 samples. L. Haury, A. 

 Morton, J. Wormuth, A. Hart, and C. Polloni pro- 

 vided valuable assistance in making the MOC- 

 NESS 1 collections at sea, and G. Flierl provided 

 helpful suggestions for interpreting the data. We 

 thank C. Miller and L. Haury for critically read- 

 ing the manuscript and we thank the officers and 

 crew of the RV Knorr and RV Chain for their 

 skillful operation of the vessels. This study was 

 supported by the Office of Naval Research con- 

 tracts N00014-66-CO241 NRO38-004, N00014- 

 74-C0252 NR083-004, and N00014-79-C-0071 

 NRO83-004 and the National Science Founda- 

 tion grants DES74-02793 AOl and OCE77- 

 09132. 



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