AHLSTROM: KIND AND ABUNDANCE OF FISH LARVAE 



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nera and species of this table according to the 

 magnitude of the seasonal change in abundance 

 that each displayed. 



Seasonal range in relative abundance between 

 highest and lowest average number of larvae 

 per haul: 



Less than 2X : Notolychnus valdiviae 



2.1 to 3X : Bathylagus nigrigenys, Diplophos tae- 



nia, Vinciguerria lucetia, Idiacan- 

 tlms sp., Bathophilus filifer, Dioge- 

 nichthys laternatus, Hygophum 

 atratiim, Hygophum proximum, 

 Notoscopeliis resplendens, Tripho- 

 turus sp. 



3.1 to 4X : Cyclothone spp., Chauliodus sp., Go- 



nichthys tenuiculiis, Coryphaena 

 spp., Howella pammelas 



4.1 to 5X : Symbolophorus evermanni, Auxis spp. 



Larvae of the above 18 genera and species 

 were taken on all cruises throughout the year. 

 Obviously, reproduction is a continuous process 

 for all of these, varying in amount at different 

 seasons of the year and at different latitudes, 

 but never stopping entirely. 



Larvae of two species dominated the collec- 

 tions from the monitoring pattern: those of 

 the myctophid Diogeuickthys laternatus and of 

 the gonostomatid, Vinciguerria lucetia. Togeth- 

 er these two species made up 44 to 56% of the 

 total larvae in the monitoring pattern (Table 

 14). 



The highest average abundance of larvae of 

 the lanternfish, Diogenichthys lateryiatus, 68.6 

 larvae in August-September, was 2.5 x as much 

 as the lowest average abundance, 31.8 larvae in 

 December-January. Larvae of this species 

 ranked first in abundance between October and 

 May, but were less abundant than larvae of 

 Vinciguerria lucetia during June-September. 

 Larvae of Vincigueriia lucetia had a range of 

 2.4 X between their highest average abundance 

 per haul, 71.9 larvae in August-September, and 

 lowest, 30.0 larvae in December-January. A 

 small but consistent change in abundance with 

 season is evident for this species, with the peak 

 period in June-September, the minimal period 

 in October-January, and intermediate abundance 

 of larvae in February-May. 



The monitoring cruises were valuable in per- 

 mitting us to establish the seasonal patterns of 



1169 



