Fate of a fallen ant: Time-resolved micro-CT analysis of ant digestion in Nepenthes pitchers

Abstract

Carnivorous pitcher plants of the genus Nepenthes have evolved highly specialized leaf-derived traps that capture and enzymatically digest insect prey to supplement nutrient acquisition in nutrient-deficient habitats. This study aimed to elucidate the structural dynamics underlying prey digestion in Nepenthes khasiana using high-resolution micro-computed tomography (micro-CT) integrated with biochemical characterization of the pitcher fluid. Three-dimensional morphometric analysis of the invasive yellow crazy ant, Anoplolepis gracilipes, experimentally incubated in N. khasiana pitcher fluid, was conducted to assess time-dependent structural degradation. Quantitative micro-CT parameters, including volume, surface area, and surface-to-volume ratio, were analyzed to visualize and quantify time-dependent structural degradation and three-dimensional morphological changes in the prey during digestion. A triphasic digestion sequence was identified - comprising rapid soft-tissue hydrolysis, progressive exoskeletal fragmentation, and stabilization of chitinous remnants. The acidic, enzymatic fluid (pH 2.5-4.0) promoted uniform degradation through synergistic enzymatic, oxidative, and acidification processes, while dissolved CO2 enhanced acid stability and catalytic efficiency. The integration of micro-CT morphometrics and biochemical insights reveals a coordinated digestion mechanism in N. khasiana, optimized for efficient prey breakdown and nutrient assimilation. ONE-SENTENCE SUMMARYMicro-CT analysis revealed a triphasic digestion process in Nepenthes khasiana, elucidating the structural and enzymatic dynamics of efficient prey degradation.