Physella acuta

Family

Physidae

Species

Physella acuta (Draparnaud, 1805)

Common name

European physa, Left-handed pondsnail, Acute baldder snail, Ashy physa, Lateritic physa, Pewter physa, Tadpole snail, Pewter physa

Description

The European physa has a sinistralSinistral:
Having the opening of the shell on the left side when the observer hold the shell so that the apex is upwards and the aperture faces them.
(left-handed) shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
that is 7-12 mm high and 7-10 mm wide, with 5-6 whorlsWhorls:
Pleural of whorl. A whorl is a complete spiral turn/growth of the shell of a mollusc. The whorls are counted from the apex outwards.
. This snail has a very large body whorlBody whorl:
The large, final coil (most recently formed) of a mollusc shell that contains the body of the snail, i.e. from the aperture to approximately one whorl back.
, relative to the rest of the shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
. The heightHeight:
The height of the shell is a measure of the distance between the apex and the most basal part of the shell OR the measurement taken from the apex of the shell to the base, when measured parallel to the axis of the shell.
of the body whorlBody whorl:
The large, final coil (most recently formed) of a mollusc shell that contains the body of the snail, i.e. from the aperture to approximately one whorl back.
accounts for approximately 75 % of the total heightHeight:
The height of the shell is a measure of the distance between the apex and the most basal part of the shell OR the measurement taken from the apex of the shell to the base, when measured parallel to the axis of the shell.
of the shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
. The vacant shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
has a tan color, but in living specimens the body whorlsWhorls:
Pleural of whorl. A whorl is a complete spiral turn/growth of the shell of a mollusc. The whorls are counted from the apex outwards.
appears mottled (black and tan spots and blotches). The apertureAperture:
The major opening of a shell that the body of the animal may be retracted.
(mouth) is oval and may have a white rib. The opaqueOpaque:
Not having the ability to see through an object. (Not transparent or translucent)
shell has a pointed spireSpire:
All the coils (whorls) of a shell above the body whorl.
and does not have a rigid structure blocking the opening of the shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
(operculum). The body of the animal is blue-grey in color with innumerable dark spots.

Distribution

North America:

• U.S.: Wyoming

Australasia: Australia, New Zealand

Asia: Hong Kong

Europe: Croatia, Germany, Netherlands, Czech Republic, Britain, Ireland

Other: Mediterranean region

Ecology

This species inhabits shallow, warm, standing fresh water in very high densities. It is able to withstand polluted water and is often introduced inadvertently into new habitats by humans. This species is very adaptable and is recorded as a serious pest of both economic plants in greenhouses and filtering vegetation in sewage treatment plants.

Synonyms

• Haitia acuta
• Physella heterostropha (Say, 1817)
• Physa globosa Haldeman, 1841
• Physella integra (Haldeman, 1841)

References

Albrecht et al. 2009; Anderson 2003; Anderson 2005; Cope and Winterbourn 2004; Semenchenko et al. 2008