Dynamics of Growth–Feeding Mechanisms in Japanese Anchovy Larvae Under Different Environmental Conditions

The linkage between growth rate and feeding success in fish larvae has received much attention as a potential indicator of future growth and survival potential. Given the increasing evidence that the growth–survival relationship is highly variable, the growth–feeding linkage would also exhibit variable dynamics among cohorts of the same population under different environmental conditions. Here, we demonstrated the dynamics of the growth–feeding linkage in Japanese anchovy larvae across multiple cohort samples collected by commercial trawlers operating in the Kii Channel, Japan. Three growth–feeding mechanisms that assume potential advantages of relatively large somatic size, high growth rate, and early morphological development for feeding success were tested for each cohort sample through both qualitative and quantitative indices of feeding success, including prey presence/absence, number, size, and carbon content. All the mechanisms were supported by at least certain cohorts, but none of them was universally effective across all cohorts. Hence, individual somatic size, growth rate per se, and morphological development influenced prey presence/absence, number, size, and carbon content at variable degrees among the different cohorts considered. Our results suggest that the relative contribution of the three growth characteristics to feeding success would vary under different environmental conditions. The observed dynamics of the growth–feeding mechanisms would influence dynamics in future growth potential and recruitment mechanisms. Meta‐regression analyses further suggested that more diverse prey size composition, smaller prey, and higher temperature would enhance the strength of the three growth–feeding mechanisms. Further investigating when and how each growth characteristic influences feeding success will contribute to understanding which individuals are more likely to achieve successful feeding, growth, and survival in a given set of environmental conditions.