Aplexa hypnorum, common name

Common name

A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...

 the moss bladder snail, is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of small air-breathing freshwater snail

Freshwater snail

A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....

, an aquatic

Aquatic animal

An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...

 pulmonate gastropod mollusk in the family Physidae

Physidae

Physidae, common name bladder snails, are a monophyletic taxonomic family of small freshwater snails, aquatic pulmonate gastropod molluscs in the clade Hygrophila....

, a family which are sometimes known as the bladder snails.

As is true of all physids, the shell is sinistral, or left-handed. The species inhabits temporary water bodies and occurs from Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 to Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

.

Distribution

The distribution of this snail is Holarctic

Holarctic

The Holarctic ecozone refers to the habitats found throughout the northern continents of the world as a whole. This region is divided into the Palearctic, consisting of Northern Africa and all of Eurasia, with the exception of Southeast Asia and the Indian subcontinent, and the Nearctic,...

. It is known to occur in:

• Czech Republic
• Germany
• Poland
• Netherlands
• Slovakia
• British Isles
• Denmark
• Norway
• Italy

Habitat

This species inhabits very shallow ponds and ditches, usually ones that dry out periodically.

Shell description

The shell

Gastropod shell

The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...

 is translucent and pale brownish in color. It is elongate with a high spire

Spire (mollusc)

A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...

 and a narrow aperture

Aperture (mollusc)

The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....

. The maximum length of the shell is about 13 mm.

In contrast to the shell, the soft parts of the animal are black or dark grey. The tentacles are long and narrow.

Life habits

This is a surprisingly active and lively snail.

Although the animals themselves die when a temporary pond dries out, the eggs are extremely resistant to desiccation

Desiccation

Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic substance that induces or sustains such a state in its local vicinity in a moderately sealed container.-Science:...

.

Further reading

• Janus, Horst, 1965. "The young specialist looks at land and freshwater molluscs", Burke, London
• Adams A.
  Arthur Adams (zoologist)
  Arthur Adams was an English physician and naturalist.Adams was assistant surgeon on board H.M.S. "Actaeon" in company with HMS Samarang in the British Navy during the survey of the Malay Archipelago, the Japan Sea, Korea and China,from 1843 to 1846. He edited the Zoology of the voyage of H.M.S....
  
   & Adams H.
  Henry Adams (zoologist)
  Henry Adams was an English naturalist and conchologist.With his brother Arthur Adams, also a noted conchologist, he wrote three volumes, 1858.-References:...
  
   (1858). The Genera of Recent Mollusca, J. Van Voorst, Plate LXXXIV, nr 2&2a.

External links

• Ecology http://hdl.handle.net/2027.42/52902
• Older records, misidentifying Aplexa elongata as Aplexa hypnorum in Utah
  Utah
  Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
  
  , USA http://dwrcdc.nr.utah.gov/rsgis2/search/Display.asp?FlNm=apleelon
• From Germany
  Germany
  Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
  
  , with shell photo available http://www.mollusken-nrw.de/forschung/artenliste.htm