Valvata piscinalis
| Valvata piscinalis | |
|---|---|
 |
|
| a live Valvata piscinalis | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| (unranked): |
clade Heterobranchia informal group Lower Heterobranchia |
| Superfamily: | Valvatoidea |
| Family: | Valvatidae |
| Genus: | Valvata |
| Subgenus: |
Cincinna Hübner, 1810 |
| Species: | V. piscinalis |
| Binomial name | |
|
Valvata piscinalis (O. F. Müller, 1774) |
|
informal group Lower Heterobranchia
Valvata piscinalis, common name the European stream valvata or European Valve Snail, is a species of minute freshwater snail with gills and an operculum, an aquatic gastropod mollusk in the family Valvatidae, the valve snails. It is also known as Cincinna piscinalis (Müller, 1774).
Subspecies of Valvata piscinalis include:
Valvata piscinalis has a somewhat pinched aperture and an attenuate spire. The spire height tends to increases in more eutrophic conditions. Shells of this species often exhibit 4–5 whorls and are white to beige with more orange to red pigmentation apically. The operculum shows spiral markings of around 10 turns, originating almost centrally.
The European valve snail can be confused with Valvata sincera, a native species in the Great Lakes; however, the United States species has a more spherical aperture, a wider umbilicus, a conical spire and more widely spaced and rough growth lines on the shell in comparison with the introduced species. In the Great Lakes, mature adult European valve snails are 5 mm high and 3–5 mm wide. In Europe, this snail has been found up to 7 mm high and 6.5 mm wide, but is usually smaller.
Dimensions of the shell are:
The animals are yellow colored, spotted grey and white, with darker pigmentation on the snout, mantle and base of the penis. Blue eyes are at the base of long tentacles. Valvatids all exhibit an external bipectinate ctenidium (respiratory organ) which is visible as the animal moves around.
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