This work focuses on the study of the invasive Golden Apple Snail (GAS), Pomacea canaliculata, identified as one of the “100 world’s worst invasive alien species”. We characterised the food digestion strategies of this pest through an analysis of the enzymes present along its digestive system and within its secreted fluids. We also explored the participation of an intracellular endosymbiont lodged in the epithelial cells of the digestive gland of the snail.
Adult snails were kept in aquariums under controlled conditions and with synchronized feeding for 48 hours before sampling. Tissues and endosymbionts were sampled. Liquid chromatography coupled to tandem mass spectrometry was applied to define the occurrence and origin of digestive enzymes along the digestive tract of P. canaliculata.
The proteome (proteins ≥ 95% confidence) was obtained from salivary glands (3,796 proteins), content of the crop (907 proteins), digestive gland (3,518 proteins), content of the style sac (792 proteins) and intestine (2,495 proteins). Later, 144 peptides from 55 peptidases, 21 peptides of 12 lipases and 250 peptides of 81 glycosidases were quantified using multiple reaction monitoring mass spectrometry. Moreover, we found 67 proteins and quantified 85 peptides of the endosymbiont. We identify two peptidases and two glycosidases of possible bacterial origin.
In synthesis, we describe a wide diversity of digestive enzymes along the digestive tract of P. canaliculata. These findings open a new field of study of these enzymes as targets for the control and eradication of this invasive species.