Field Experiments, Behavioral Analyses, and Digestive Physiology Reveal the Selective Oyster-Feeding Strategy of Thais luteostoma

Pearl oyster aquaculture is severely constrained by biofouling organisms, particularly fouling oysters, which substantially impair pearl oyster growth and farming efficiency. This study investigated the selective oyster-feeding behavior of the predatory gastropod <i>Thais luteostoma</i> and evaluated its potential as an ecological biofouling control agent in pearl oyster culture. Field co-culture experiments showed that <i>T. luteostoma</i> did not adversely affect the survival of <i>Pinctada fucata martensii</i>, while effectively reducing biofouling loads and significantly improving pearl oyster growth performance. Laboratory behavioral assays and quantitative analyses revealed a pronounced feeding preference for oysters in <i>T. luteostoma</i>, as evidenced by a higher number of feeding individuals, longer total feeding duration, and greater spatial overlap between feeding hotspots and oyster locations. In addition, digestive enzyme assays indicated marked post-feeding physiological responses in <i>T. luteostoma</i>, with a stronger induction of digestive activity in the digestive gland than in the stomach. Collectively, these findings suggest that <i>T. luteostoma</i> represents a promising and sustainable biological option for managing biofouling in pearl oyster aquaculture, with potential applicability to other high-value bivalve farming systems.