FISHERY BULLETIN: VOL. 76. NO. 3 



2. Or 



1.0- 



D3 SS N) N2 N3 N4 SR Dl D2 D3 



2 f— 

 "" C. warmingi 



»« 



3.05 



20r 



1.0 



~1 1 — \ 1 1 1 r~ 



D3 SS Nl N2 N3 N4 SR Dl D2 D3 



I I \ 1 1 1 1 



1600 2000 0000 0400 0800 1200 1600 

 TIME OF DAY 



D3 SS Nl N2 N3N4 SR Dl 



D. schmidti 



D2 D3 



h 



f 



— I 1 1 — I — I — I 1 1 1 1 — 



D3 SS Nl N2 N3 N4 SR Dl D2 D3 



I 1 1 1 1 1 1 



1600 2000 0000 0400 0800 1200 1600 

 TIME OF DAY 



Figure l. — Medians (dots), means ( x's), and ranges between 25th and 75th percentiles (solid vertical lines) of stomach fullness as 

 percentage of body weight throughout the diel cycle for four species of myctophids: Benthosema suborbitale, Bolinichthys longipes, 

 Ceratoscopelus warmingi, and Diaphus schmidti. Values are positioned at the midpoint of each sampling period (Hawaiian Standard 

 Time). Dashed vertical lines indicate significant differences between adjacent pairs (circle — 0.05<P<0.10, * — 0.01<P<0.05, 

 diamond — P<0.01; two-tailed probabihties, Rank Sum test). 



was no apparent correlation between number of 

 trematodes and amount of food in the gut. 



There were highly significant differences 

 (P <0.005) in stomach fullness over the diel cycle. 

 The medians and means both showed a trend simi- 

 lar to that of B. suborbitale but more of the adja- 

 cent pairs showed significant differences and the 

 changes in variability were not as great as with 

 the latter species. The percentage of empty 

 stomachs was <10% at all periods except SS 

 (35%). 



Small euphausiids, P/ewromamma, and a vari- 

 ety of small ( < ca. 2 mm PL) copepods occurred in 

 the stomachs. Even though the stomach parasites 

 apparently broke up the prey items soon after in- 

 gestion, there were identifiable pieces of prey in 



500 



the stomachs from night or dawn. In contrast, con- 

 tents from day-caught specimens (particularly D2 

 and D3) were usually amorphous pink material; 

 even the apparently resistant P/euromamma but- 

 tons occurred infrequently. 



Ceratoscopelus warmingi (Figure 1) 



There were significant (P<0.01) diel differences 

 in stomach fullness for C warmingi. Similar to the 

 above two species, median stomach fullness was 

 lowest at SS and peaked at SR with an apparent 

 decline in between. The peak at SR, based on only 

 five specimens, differed marginally iP <0. 10) from 

 values before or afterwards. Day values were com- 

 parable with those at night and showed no clear 



