Physicochemical Determinants of Macrophyte Selection by Pomacea canaliculata and the Implication for Lake Restoration

The restoration of aquatic macrophytes is a critical component of lake wetland rehabilitation, however, these efforts are increasingly threatened by the spread of golden apple snail ( Pomacea canaliculata ). To identify the drivers of its feeding preferences, we evaluated ten common macrophyte species representing multiple growth forms and assessed how their physical traits, chemical traits, and decay-induced texture changes influence snail foraging. Although the ten species exhibited no significant differences in carbon (C) content or tissue cohesiveness, they showed significant variation in key chemical attributes (nitrogen, phosphorus, total phenolics, flavonoids, cellulose) and physical properties (hardness, springiness, chewiness, toughness, resilience). These interspecific variations in physicochemical characteristics persisted in decay mode. The foraging preference of P. canaliculata showed significant negative correlations with macrophyte carbon content, hardness, toughness, and chewiness. Moreover, regardless of plant decay state, snail consumption, residence frequency, and selectivity index were consistently higher for submerged macrophytes than for emergent or floating-leaved species. Although preference patterns varied among four submerged taxa, overall feeding on submerged macrophytes remained significantly and consistently higher. Given that the recovery of submerged vegetation is central to lake wetland restoration, our findings highlight a critical management challenge: restoration activities may inadvertently promote the expansion of P. canaliculata populations. These results emphasize the need to integrate proactive snail control measures into macrophyte restoration strategies.