Clea helena is a species of a freshwater snail from the family Buccinidae. Buccinidae is a marine family with over 500 species. But the genus Clea is the only genus of Buccinidae, that invaded freshwater habitats. There are 8-10 freshwater species in the genus Clea.
Clea helena has typical characteristics of Buccinidae:
* It is a scavenger or predator.
* It have a siphon in the siphonal notch. (Longer structure for the siphon is called siphonal canal, but the Clea helena has just a siphonal notch.)
* It have also an operculum, of course.
Clea helena lives on the sandy bottom or in the muddy and sandy bottom in lower reaches of rivers in Southeast Asia. The long inhalating siphon is usually stretched forward or upward. It serves very well for breathing in the mud and it probably helps to locate the decaying animals or a live prey according its smell. Its live prey are other species of snails. Clea helena snails are often burried or partially burried in the substrate. The shell is at least partly covered by the muddy sediment, that could be a good camouflage.
This width of this empty shell is 7.5 mm and the height is 15 mm. I did not find an opeculum in the substrate because the opeculum is quite small and it have a silimar color as the sand in my aquarium.
Two oblique views of the shell show the siphonal notch:
The width of the shell of this live specimen is 7 mm and the height of the shell is 14 mm. The opeculum is covering an aperture.
The color of the shell is yellow and brown. The sculpture of the shell has ribs.
Abapaertural view of a shell and dorsal view of the snail:
The foot and head region is patched in yellow and gray color. Fully extended snail:
Ventral side of the foot have the same color as the rest of the body:
Right side views:
Frontal view of the snail shows its tentacles, position of its eyes and siphon. Umbilical view of a shell.
Left side view:
Clea helena have separate sexes (some snals are males and some are females), but I have no idea, what is the gender of the specimen on these my photos. I have not seen them mating yet.
References
Strong E. E., Gargominy O., Ponder W. F. & Bouchet P. (2008). “Global Diversity of Gastropods (Gastropoda; Mollusca) in Freshwater”. Hydrobiologia 595: 149-166. hdl:10088/7390 doi:10.1007/s10750-007-9012-6.