Gyraulus (Gyraulus crenophilus)

Description

Gyraulus fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Gyraulus description

Gyraulus crenophilus is a species of snail in the Planorbidae family, members of which have a shell that is disc-like and flattened in appearance ^{(4) (5)}.

The shell of Gyraulus crenophilus has 3.5 to 4 whorls, the last of which is smoothly rounded, and the shell is marked with fine, spiral lines ⁽²⁾. This species has a moderate umbilicus, and the shell is often covered in algae. The body of Gyraulus crenophilus is grey to blackish ⁽²⁾, and the tentacles, which are long and slender in members of the Planorbidae family ⁽³⁾, are usually densely pigmented ⁽²⁾.

Size

Shell diameter: up to 7 mm ^{(2) (3)}

Gyraulus biology

There is little available information on the biology of Gyraulus crenophilus. However, members of the Planorbidae family are known to be hermaphroditic, with an individual snail possessing both male and female sexual organs ⁽⁴⁾. Planorbidae are pulmonates, meaning that they can breathe air, which enables some members of the family to survive generally unfavourable, low-oxygen conditions. Planorbidae species can also absorb oxygen directly from the water ⁽⁴⁾.

The diet of most Planorbidae species consists of plant matter, with some species feeding on fresh plants and algae, and others feeding on decaying plant matter ^{(4) (6)}.

Gyraulus range

Gyraulus crenophilus is endemic to Lake Ohrid in the Former Yugoslav Republic of Macedonia ^{(1) (2)}, and also occurs in springs that feed into the lake, some of which are located in Albania ⁽¹⁾.

Gyraulus habitat

Gyraulus crenophilus is a freshwater species, only inhabiting the edge or springs of Lake Ohrid, where it can be found on stones and rocks ^{(1) (2)}. This species has a preference for a constant water temperature of 12 to 13 degrees Celsius ⁽²⁾.

Gyraulus status

Gyraulus crenophilus is classified as Endangered (EN) on the IUCN Red List ⁽¹⁾.

Gyraulus threats

A restricted range species, Gyraulus crenophilus is vulnerable to alterations to its habitat ⁽¹⁾. A number of pollutants are currently entering the streams and lake where Gyraulus crenophilus is present, including sewage from nearby cities, agricultural contaminants and an increasing amount of sediment due to deforestation in the catchment area of these water bodies. Over-extraction of water is also having a negative impact on this species in some parts of its range ⁽¹⁾.

Gyraulus conservation

There are currently no known conservation measures in place for Gyraulus crenophilus, although monitoring and careful habitat management are suggested actions to conserve this rare snail ⁽¹⁾.

Find out more

Find out more about Gyraulus crenophilus:

• AnimalBase - Gyraulus crenophilus:
  http://www.animalbase.uni-goettingen.de/zooweb/servlet/AnimalBase/home/species?id=2083

Authentication

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Glossary

Algae

Simple plants that lack roots, stems and leaves but contain the green pigment chlorophyll. Most occur in marine and freshwater habitats.

Endemic

A species or taxonomic group that is only found in one particular country or geographic area.

Hermaphroditic

Possessing both male and female sex organs.

Pulmonate

Of or belonging to the Pulmonata, a group of gastropods which are capable of breathing air through lunglike sacs. Includes terrestrial snails and slugs and certain freshwater snails.

Umbilicus

In gastropod molluscs, such as snails, a depression or hole on the underside of the shell, at the centre of the whorls (the spirals or coils of the shell). It is present in many but not all snail species.

Whorls

In animals, the spirals or coils in the shell of a snail. In plants, a set of leaves, flowers, or branches that spring from a stem at the same point and encircle it.

References

1. IUCN Red List (December, 2011)
   http://www.iucnredlist.org/
2. AnimalBase - Gyraulus crenophilus (December, 2011)
   http://www.animalbase.uni-goettingen.de/zooweb/servlet/AnimalBase/home/species?id=2083
3. Brown, D. (2005) Freshwater Snails of Africa and their Medical Importance. Taylor & Francis, London.
4. Baker, F.C. (1945) The Molluscan Family Planorbidae. The University of Illinois Press, Urbana.
5. Oscoz, J., Galicia, D. and Miranda, R. (Eds.) (2011) Identification of Freshwater Macroinvertebrates of Spain. Springer, Dordrecht, Heidelberg, London and New York.
6. Recknadel, F. (Ed.) (2003) Ecological Informatics: Understanding Ecology by Biologically-Inspired Computation. Springer, Berlin and Heidelberg.