FISHERY BULLETIN: VOL. 76, NO. 3 



k' = k from Equation (1) and the other using k ' = 

 0.10, the value for D. oculatus. 



The estimated ration for Vinciguerria nimbaria 

 seems inordinately high (18%) if/?' is assumed 

 equal to k, the nighttime estimate of evacuation 

 rate. Such values have been estimated for very 

 young, rapidly growing zooplanktonivorous 

 fishes, e.g., A/osa aestivalis (Burbidge 1974) and 

 Oncorhynchus gorbuscha (Parsons and LeBras- 

 seur 1970). Data from Kjelson and Johnson's 

 1 1976) study of postlarval Lagodon rhomboides 

 and Leiostomus xanthurus feeding rates on zoo- 

 plankton yield estimates of daily ration of only 9.4 

 and 8.69c , respectively, in terms of wet weight ( my 

 calculations from their data). The estimated ra- 

 tion for V. nimbaria using the low value for /? ' and 

 that for//, proximum lie within the range of val- 

 ues observed for larger individuals in the first two 

 studies cited above and for Morone chrysops 

 juveniles feeding on zooplankton (Wissing 1974). 

 The daily ration of the California sardine, Sar- 

 dinops caerulea, which is a larger zooplanktoni- 

 vore, is apparently slightly lower; judged from 

 Lasker's (1970) estimates of metabolic and grovvd:h 

 requirements, the daily ration is probably about 

 3-4% ( in terms of calories) for the sizes considered. 



The above comparisons are admittedly 

 stretched and ignore, among other things, possible 

 differences due to environmental temperature, 

 but the similarity of estimated daily rations of//. 

 proximum and V. nimbaria to those of shallow- 

 living planktonivores is not entirely unexpected. 

 Childress and Nygaard (1973) have shown that 

 the chemical composition of mesopelagic fishes 

 which migrate to the upper layers at night is more 

 similar to that of epipelagic species than to non- 

 migrating, deep-living forms. 



Differences between estimates for the three 

 stomiatoids are correlated with the extent of verti- 

 cal migration. Nighttime stomach evacuation rate 

 is highest in V. nimbaria, lowest in D. oculatus, 

 and intermediate in Valenciennellus 

 tripunctulatus. Feeding rate and daily ration es- 

 timates show the same trend regardless of 

 whether or not daytime stomach evacuation rates 

 are assumed lower. The absolute values of 

 stomach fullness at the end of the feeding period 

 (Figure 3) are also highest in Vinciguerria nim- 

 baria and lowest in D. oculatus. These trends in- 

 dicate a possible adaptive value for the upward 

 migrations of some stomiatoids. The higher tem- 

 peratures encountered at night by migrators could 

 allow processing of larger meals and presumably 



faster growth, turnover, etc., rates than for species 

 which remain at depth day and night. 



ACKNOWLEDGMENTS 



I thank the captain and crew of the RV Teritu 

 for their cooperation on their vessel's final cruise; 

 the many people who assisted in collection of the 

 samples; P. J. Wagner and G. L. Hoff for careful 

 and competent sorting of the fishes and dry weight 

 determinations, respectively; and K. Gopala- 

 krishnan for identification of euphausiids and de- 

 capods. This research was supported by NSF GA- 

 38423 and the State of Hawaii, Hawaii Institute of 

 Marine Biology. 



LITERATURE CITED 



Anderson, R. 



1967. Feeding chronology in two deep-sea fishes off Cal- 

 ifornia. M.S. thesis, Univ. South. Calif., Los Ang., 11 p. 



Baird, R. C, T. L. Hopkins, and D. F. Wilson. 



1975. Diet and feeding chronology of Diaphus taaningi 

 (Myctophidae) in the Cariaco Trench. Copeia 

 1975:356-365. 

 BRINTON, E, 



1967. Vertical migration and avoidance capability of 

 euphausiids in the California Current. Limnol. 

 Oceanogr. 12:451-483. 

 BURBIDGE, R. G. 



1974. Distribution, growth, selective feeding, and energy 

 transformations of young-of-the-year blueback herring, 

 Alosa aestivalis (Mitchill), in the James River, Virgin- 

 ia. Trans. Am. Fish. Soc. 103:297-311. 



CHILDRESS, J. J. 



1975. The respiratory rates of midwater crustaceans as a 

 function of depth of occurrence and relation to the oxygen 

 minimum layer off Southern California. Comp. 

 Biochem. Physiol. 50A:787-799. 



Childress, J. J., and M. H. Nygaard. 



1973. The chemical composition of midwater fishes as a 

 function of depth of occurrence off southern 

 California. Deep-Sea Res. 20:1093-1109. 



Clarke, T. A. 



1973. Some aspects of the ecology of lantemfishes (Myc- 

 tophidae) in the Pacific Ocean near Hawaii. Fish. Bull., 

 U.S. 71:401-434. 



1974. Some aspects of the ecology of stomiatoid fishes in 

 the Pacific Ocean near Hawaii. Fish. Bull., U.S. 

 72:337-351. 



Clarke, T. A., and P. J. Wagner. 



1976. Vertical distribution and other aspects of the ecology 

 of certain mesopelagic fishes taken near Hawaii. Fish. 

 Bull., U.S. 74:635-645. 



DeWITT, F. a., JR , AND G. M. CaILLIET. 



1972. Feeding habits of two bristlemouth fishes, Cv- 

 clothone acduudens and C. signata (Gonostomatidae). 

 Copeia 1972:868-871. 

 EGGERS, D. M. 



1977. Factors in interpreting data obtained by diel sam- 



512 



