FISHERY BULLETIN: VOL. 70, NO. 4 



Table 9. — Standardized counts of fish larvae compared with unstandardized (original) counts, summarized for 



selected families (see Appendix Table 8 for standardized haul factors). 



Relative abundance of fish as larvae is not 

 necessarily proportional to their relative abun- 

 dance as adults. A number of parameters would 

 have to be evaluated if counts of eggs and larvae 

 of a species are to be used in determining the 

 biomass of adult populations. These include fe- 

 cundity (preferably given as number of eggs 

 spawned in relation to fish weight — such as 

 number of eggs spawned per gram of female 

 weight) ; egg size, which influences size and 

 state of development at hatching; duration of 

 time spent in plankton both as egg stage and as 

 larva as related to temperature of development ; 

 mortality rates during embryonic and larval 

 stages; size at transformation; length of spawn- 

 ing season; age structure of population; etc. 



I am assuming that the relative abundances 

 of larvae of a given species are comparable from 

 cruise to cruise in the EASTROPAC area. I am 

 further assuming that comparisons of relative 

 abundance within a family, as for example 

 among myctophid or among scombrid larvae, 

 will reflect their relative abundance as adults 

 within reasonable limits. I, however, would 

 caution against taking comparisons between 

 families too literally until essential parameters 

 are evaluated for each. 



Actual counts of larvae rather than stan- 

 dardized values are used in tabulations through- 

 out the paper, except Table 9. Table 9 com- 

 pares summations of larvae of selected families 

 based on standardized values with summations 

 based on actual counts. These families make 

 similar percentage contributions to the larval 

 catch whether based on standardized counts or 

 actual counts. 



COMPARISON OF COMPOSITION AND 



RELATIVE ABUNDANCE OF LARVAE 



IN EASTROPAC II AND EASTROPAC I 



COLLECTIONS 



In order to keep comparisons between the 

 two EASTROPAC multivessel cruises com- 

 pletely relevant, the following stations lacking 

 counterparts in ETP II were omitted from 

 ETP I summations: Stations 11.146 to 11.328 

 of the outer pattern occupied by Argo, Stations 

 12.122 to 12.164 of the adjacent pattern occu- 

 pied by David Starr Jordan, and Stations 13.095 

 to 13.155 of the next to inner pattern occupied 

 by Rockaway. The remaining stations, by hap- 

 py coincidence, total 355, are identical to the 



1164 



