Dynamics of growth-based survival mechanisms in Japanese anchovy Engraulis japonicus larvae

Three growth-based survival mechanisms were tested for multiple cohorts of Japanese anchovy Engraulis japonicus larvae in Sagami Bay. Through otolith microstructure analysis, growth trajectories and histories of samples of the survivors were compared with those of the original populations to examine size- and growth-selective mortality to test the “bigger is better” and “growth-selective predation” mechanisms, respectively. The effects of growth rates on the timing of metamorphosis were examined to test the “stage duration” mechanism. The “bigger is better” and “growth-selective predation” mechanisms were detected to be effective in 2 and 6 of 8 seasonal cohorts, respectively. Results contrary to the “bigger is better” and “growth-selective predation” mechanisms were obtained from 3 and 2 of 8 cohorts, respectively. The “stage duration” mechanism was evaluated to be effective for both of 2 cohorts which were testable. Overall, none of the three mechanisms was universally appropriate for all of the cohorts. The relative contributions of the three mechanisms were dynamic, although the “growth-selective predation” mechanism was identified to be the major one in anchovy larvae in the study site.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author