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

## TL;DR

A predatory snail called Thais luteostoma selectively eats fouling oysters without harming pearl oysters, offering a sustainable solution for aquaculture.

## Contribution

The study demonstrates the snail's selective feeding behavior and its potential as a biological control for biofouling in aquaculture.

## Key findings

- T. luteostoma reduced biofouling and improved pearl oyster growth in field experiments.
- Behavioral assays showed a strong feeding preference for oysters in T. luteostoma.
- Digestive enzyme activity was significantly higher in the digestive gland after feeding.

## Abstract

Biofouling organisms, especially oysters, commonly attach to cultured pearl oysters and can seriously reduce growth performance and farming efficiency. Conventional fouling removal relies on frequent manual cleaning, which is labor-intensive, costly, and may cause physical damage to cultured animals. In this study, we found that the predatory gastropod Thais luteostoma naturally and selectively feeds on fouling oysters without harming the pearl oyster Pinctada fucata martensii. Field co-culture experiments showed that the presence of T. luteostoma effectively reduced biofouling organisms and indirectly promoted pearl oyster growth. Behavioral observations confirmed that T. luteostoma actively targets oysters, and digestive enzyme analyses demonstrated clear physiological responses following feeding. These findings suggest that T. luteostoma could serve as a potential biological control option for managing biofouling in pearl oyster aquaculture and potentially in other bivalve farming systems.

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 Thais luteostoma and evaluated its potential as an ecological biofouling control agent in pearl oyster culture. Field co-culture experiments showed that T. luteostoma did not adversely affect the survival of Pinctada fucata martensii, 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 T. luteostoma, 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 T. luteostoma, with a stronger induction of digestive activity in the digestive gland than in the stomach. Collectively, these findings suggest that T. luteostoma represents a promising and sustainable biological option for managing biofouling in pearl oyster aquaculture, with potential applicability to other high-value bivalve farming systems.