FOLKVORD and HUNTER: VULNERABILITY OF NORTHERN ANCHOVY LARVAE 



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STANDARD LENGTH (mm) 



Figure 4.— Percentage of northern anchovy larvae that responded to attacks by adult northern anchovy (lines for the 

 three different predator groups shown separately), chub mackerel and the aquarium fish Amphiprion percula (from 

 Webb 1981). 



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 LARVAL STANDARD LENGTH (mm) 



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Figure 5.— The percentage of responding northern anchovy larvae in various length classes that escaped the predator. 



Species names identify the predator species. 



lack of pigmentation, 6 mm larvae may have been 

 less visible to the predators than larger larvae and 

 consequently were detected less frequently. The 

 decline in predation rates in larvae longer than 15 

 mm was the result of their greater escape ability. 

 The number of larvae consumed in 5 min was an 

 insensitive measure of predation rates of chub 

 mackerel, because they usually ate all larvae in the 



tank within 5 min regardless of their size. Only in 

 the two smallest larval size groups (6-10 mm SL) 

 were some larvae left after a 5-min elapsed time; 

 the deletion of one experiment because of low chub 

 mackerel predator performance changed the preda- 

 tion rate on 10 mm larvae from 87 to 95% (dashed 

 line in Figure 3A). These adjusted data indicate that 

 the feeding rate of chub mackerel was lowest when 



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