Chinese mystery snail

Chinese mystery snail
A live individual out of water
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Caenogastropoda
Order: Architaenioglossa
Family: Viviparidae
Genus: Cipangopaludina
Species:
C. chinensis
Binomial name
Cipangopaludina chinensis
(Gray, 1834)
Synonyms
  • Paludina chinensis Gray, 1834 (original combination)
  • Bellamya chinensis (Gray, 1834)
  • Vivipara chinensis (Gray, 1834)
  • Viviparus chinensis malleatus (Reeve, 1863)
  • Viviparus japonicus
  • Viviparus stelmaphora
  • Paludina malleata
  • Paludina japonicus

The Chinese mystery snail, black snail, or trapdoor snail (Cipangopaludina chinensis), is a large freshwater snail with gills and an operculum, an aquatic gastropod mollusk in the family Viviparidae. The Japanese variety of this species is black and usually a dark green, moss-like alga covers the shell.

The name "trapdoor snail" refers the operculum, an oval corneous plate that most snails in this clade possess. When the soft parts of the snail are fully retracted, the operculum seals the aperture of the shell, providing some protection against drying out and predation.