FISHERY BULLETIN: VOL. 77, NO, 4 



Subfomily Lamponyclinae 



Bolinichthys disfofOJr 

 Bolinichthys longipes 

 Cerafoscopelus vvarnmgi 

 Dtaphus onderseni 

 Diaphus tyachycepholus 

 Oaphus e/ucens 

 D'ophus roffboltni 

 Lompadena tummosa 

 Lampanycrus nobihs 

 LdmpanycTus sfeinbecki 

 Lobionchia gsmelldn 

 Nofofychnus valdivide 

 Tnpho/urus nigrescens 



Subfomily Myclophmae 



Benthosemo suborbitale 

 Diogenichthys oflonlicus 

 Hygophum proximt/m 

 Hygophum remhardti 

 Myctophum nifidulum 

 Symbolcphorus evermonn: 



DEPTH (m) 

 100 200 



O Ijrvoe 



Figure 10. — Larval (upper bar) and juvenile eind adult (lower 

 bar) nighttime depth distributions for the more abundant 1am- 

 panyctine and myctophine (Myctophidae) species taken in late 

 summer near lat. 28° N, long. 155° W (North Pacific central 

 gyre). Hatched larval depth range indicates depth intervals 

 where ^90% of the estimated water column abundance occurred. 

 Adult depth distributions from Clarke (1973). 



{except for Hygophum spp.), wherein all sizes tend 

 to be distributed above the depths of maximum 

 larval abundance. In most cases the largest adults 

 of both subfamilies are vertically separated from 

 the larvae, and, where overlap occurs, the smallest 

 juveniles are in similar depth ranges with the 

 largest larvae. 



A variety of patterns of early developmental 

 stages were found. Among the gonostomatids, 

 metamorphic stages of Cyclothone alba and Vin- 

 ciguerria spp. were found in stratified samples. 

 Apparently C. alba leaves the larval depth range 

 once it has reached the prometamorphic stage of 

 development. Vinciguerria spp. go through all 

 early metamorphic stages while in the larval 

 depth range and presumably descend to greater 

 depths once the postmetamorphic stage is com- 

 pleted. For both C. alba and V. nimbaria the ad- 

 vanced stages of larval development were found in 

 the lower portion of the larval depth range. 

 Gradual downward migration with development, 

 as seen in V. nimbaria, may also occur in Valen- 

 ciennellus tripunctulatus and Gonostoma spp. 

 (Badcock and Merrett 1976). 



The myctophid species exhibited different levels 

 of photophore development before descending to 

 juvenile depths. Developmental series from early 

 larvae to transforming individuals were found 

 from 5=350 m for 11 of the 31 myctophid species 



792 



taken in Climax I. These include: six of the seven 

 Diaphus species (all but D. schmidti), Lobianchia 

 gemellari, Notolychnus valdiviae, Benthosema 

 suborbitale, Diogenichthys atlanticus, and 

 Hygophum reinhardti . At least some individuals 

 of Diaphus spp., L. gemellari, N. valdiviae, andD. 

 atlanticus complete transformation before descent 

 to juvenile depths or else begin extensive migra- 

 tions before transformation. The presence of 

 lightly pigmented juveniles of D. anderseni, D. 

 elucens, N. valdiviae, B. suborbitale, and H. rein- 

 hardti in the upper 100 m at night indicated that, 

 if these are not predescent individuals, some 

 members of these species may undergo early 

 juvenile migration. 



No late photophore stage larvae were found for 

 Bolinichthys spp., Ceratoscopelus warmingi, 

 Lampadena spp., Lampanyctus spp., Triphoturus 

 nigrescens, H. proximum. Myctophum spp., or 

 Symbolophorus evermanni in either the Climax I 

 samples or 0-300 m IKPT samples taken on other 

 gyre cruises. These larvae appear to leave the 

 upper 300 m of the water column at varying levels 

 of early photophore development prior to trans- 

 formation. The late stages of photophore develop- 

 ment probably occur at the juvenile day depth 

 range for each species. The developmental state at 

 descent appears to be a generic characteristic 

 within both subfamilies. Except for Hygophum 

 spp., congeners achieved similar levels of photo- 

 phore development while in the upper 300 m. 



Due to small numbers of other larvae captured, 

 little can be ascertained about their distributional 

 patterns. Most species occurred in the upper 100 

 m, with greatest numbers of species at 25-50 m. 

 Basic trends in depth distribution appeared to 

 exist on a familial or ordinal level: Notosudidae 

 were most abundant at 0-25 m; five families of 

 ceratioid fishes occurred in the upper 50 m; four 

 families of stomiatoid fishes and the Ever- 

 mannellidae occurred most frequently at 25-75 m; 

 Bregmacerotidae and Melamphaeidae were most 

 abundant at 75-100 m; and Scopelarchidae, 

 Bathylagidae, and Sternoptychidae occurred 

 below 100 m. The paralepidids (much like the 

 myctophids) exhibited a variety of depth distribu- 

 tions through the upper 225 m. 



The depth distributions described are for the 

 late summer central gyre ichthyoplankton as- 

 semblage. Surface temperature is 6°-7° C lower in 

 winter and the mixed layer depth increases from 

 ca. 40 m in late summer to 110-140 m in winter 

 (McGowan and Williams 1973). There are also 



