FISHERY BULLETIN: VOL. 71, NO. 2 



at POL, VLO, SAO-3, Pol, and Prc-4. In 8 out 

 of 20 specimens over 50 mm, there was acces- 

 sory tissue at PO-4, V03, or both. 



Only small (<20 mm) D. "glandulifer" were 

 caught above 150 m, the larger individuals 

 being around 200 m and deeper at night. This 

 species was rare at all seasons, and most 

 specimens were either in a 27-39 mm group or 

 over 45 mm. Catches of a few less than 20 mm 

 suggest that this species may occasionally 

 spawn in the area. 



Dijphns sch)niciti 



There was no indication that any sizes of 

 D. schmidti sampled by the trawl did not 

 regularly migrate to the upper layers at night. 

 There were significant differences in size- 

 frequency curves from different depths at night. 

 The number and percentage of juveniles (<25 

 mm) were greatest around 25 m. The number of 

 larger fish was greatest at 50 m, but the 

 percentages of small and large fish were 

 roughly equal. At 75-80 m most or all the 

 individuals were larger. Only the day samples 

 from March 1971 were spaced closely enough to 

 suggest that there were similar size-frequency 

 changes within the day depth range. 



Because D. schmidti occurred over a 

 relatively narrow depth range during the day 

 and was frequently caught in only one tow 

 per series, it was impossible for some series 

 to assign realistic weighting factors for calcula- 

 tion of total numbers. However, the calculated 

 night size-frequency curves agreed closely with 

 those of the day samples. 



The calculated size-frequency curves for CT 

 and IK in March 1971 agreed quite closely, but 

 the calculated total for the CT was 15 x that of 

 the IK. The difference in totals was due to rela- 

 tively much greater catches by the CT at 75 

 and 100 m. The CT caught only 1.7 and 6.3 x 

 the IK at 25 and 50 m, but caught 65 and 45 x 

 more at 75 and 100 m, respectively. The pairs 

 of individual size-frequency curves at 25 and 

 50 m differed significantly and indicated that 

 the IK caught more larger fish, while the curves 

 at 75 and 100 m from the CT did not differ from 

 those of the IK at 80 m. Since both large fish 

 and juveniles occurred shallower and only 



large fish deeper, it appears that the CT under- 

 sampled larger fish in shallow zones and the 

 IK undersampled them in deeper zones. 



The full moon samples indicated that peak 

 depth was around 75 m and caught none at 

 20-50 m where new moon tows indicated maxi- 

 mum abundance. The calculated total for full 

 moon was about three-fourths that of new 

 moon, and the calculated size-frequency curves 

 indicated a somewhat larger proportion of 

 juveniles during full moon. Thus D. schmidti 

 occurs deeper at full moon, and larger indi- 

 viduals may avoid the net more frequently. 



D. schmidti apparently spawns in late spring 

 and summer and matures in about 1 year. In 

 June 1971, the population consisted mostly of 

 either juveniles or adults with few individuals 

 between 20 and 30 mm. Both juveniles and 20- 

 to 30-mm individuals were present in September 

 1970 and 1971. In December 1970, almost all 

 were 20-30 mm, and in March 1971, almost all 

 were over 30 mm. Percentages of ripe females 

 were significantly higher in the March and 

 June 1971 series than in the September 1971 

 series. Practically none were mature in De- 

 cember 1970. 



Diitphns frugilis 



D. fragilis was caught most frequently at 

 night at 25-50 m (new moon) and 100-125 m 

 (full moon). The CT catches were low and did 

 not indicate that this species was avoiding the 

 IK in appreciable numbers. D. fragilis was 

 distinctly more abundant in September 1970 

 and 1971 and leafet so in December 1970 and 

 March 1971. It is one of the dominant species 

 of myctophids in Pacific equatorial waters 

 (Hartmann, 1971) but its presence in low 

 numbers near Hawaii cannot be ascribed 

 entirely to immigration. Fair numbers of small 

 (<20 mm) individuals were caught in Septem- 

 ber, suggesting that some spawning occurs in 

 the summer. 



Diiiphns rolfholifii 



Pooled size-depth data indicated that D. 

 rolfbolini <20 mm occurred principally above 

 100 m, those 20-45 mm around 100 m, and 



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