FISHERY BULLETIN: VOL. 86, NO 1 



Table 5. — Comparisons of relative abundances of dominant larval fish taxa collected off of northern Chile (18- 

 24°S, 70°-72 W) during July-September sampling periods, 1964-83. Relative abundances within each year are 

 presented as (A) percentage contribution to total identified larvae and (B) ranked abundance. Taxa are listed in 

 order of total summed 10-yr mean abundances 



in 1966, 1972, and 1973 and relatively rare in 

 1965 and 1968. The ranked abundance patterns of 

 each of the components differ from one another 

 (e.g., all pairwise correlation coefficients 

 [p = —0.21 to +0.61] are nonsignificant). Larval 

 diversity is strongly correlated with total larval 

 abundance (p = +0.88, P < 0.01). 



There are no significant correlations between 

 abundance ranks of invertebrate zooplankton 

 biomass and total larvae (p = +0.27) or any of the 

 larval categories (p = -0.03 to +0.22; P > 0.05 in 

 all cases). 



Species Abundance Variations 

 and Relations 



The top 10 ranking larval fish taxa were caught 



during at least 9 of the 10 sampling periods (Table 

 4). All of these taxa exhibited large interannual 

 abundance fluctuations (Table 3). Most marked 

 were the abundance changes of anchoveta, sar- 

 dine, and coastal species Normanichthys crockeri. 

 This latter species (rank 3 in overall abundance) 

 was frequently abundant prior to 1983; like an- 

 choveta it was absent from 1983 samples. Among 

 the 10 taxa only Triphoturus mexicanus had 

 <10x changes in mean abundance values; <20x 

 changes occurred for Lampanyctus parvicauda 

 (11.5X) and Diogenichthys spp. (18.4x); all other 

 taxa had >20x mean abundance changes over 

 the 10 years. The abundance fluctuations of these 

 10 taxa are primarily responsible for the interan- 

 nual abundance and composition variations 

 (Table 5; Fig. 3A, B). 



10 



