Widespread mislabeling of nonnative apple snails (Ampullariidae: Pomacea) as native field snails (Viviparidae: Cipangopaludina) on the Chinese food markets

Abstract

Freshwater snails have been used extensively as a human food source in different countries for centuries. Due to increasing cases of fraudulent substitution or mislabeling affecting the safety and quality of food products, food authenticity has aroused crucial concern. This study aimed to identify processed freshwater snail products that were sold under the commercial term Tian luo in Chinese, which means local field snails and refers to Cipangopaludina spp. A total of 100 samples of snail skewers, snail snacks, and snail sauces from the online food market were tested. Species were diagnosed based on a combined analysis of the morphological characteristics and mitochondrial COI fragments. Our results demonstrated 100% improper labeling of Tian luo processed food in food market of China. All snails in the skewers and snacks were nonnative apple snails from the genus Pomacea. The snails in the snail sauces were from Bellamya, which is a genus closely related to Cipangopaludina. The most commonly used apple snail species was P. maculata, followed by P. canaliculata. One specimen was identified as P. occulta, which is a newly described species that has thus far only been reported in China. A comparison of the distribution patterns of the Pomacea spp. from the food market and the natural habits in China indicated that the majority of the snail material was probably imported especially from other Asian countries, whereas a small proportion was likely farmed or collected in China. Apple snails pose food safety concerns because they host various zoonotic parasites. Moreover, we detected the presence of toxic female albumen glands on the apple snail skewers. Our results emphasize the importance of effective supervision and standardization of food treatment measures in freshwater snail foods.