''Semilimax pyrenaicus'' is a
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of air-breathing
land snail
A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial molluscs, terrestrial gastropod mollusks that have gastropod shell, shel ...
, a
terrestrial pulmonate
Pulmonata or pulmonates is an informal group (previously an order, and before that, a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group inclu ...
gastropod
Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, freshwater, and fro ...
mollusk
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...
in the family
Vitrinidae. It is a large greyish-brown snail that cannot fully retract into its shell.
Description
For terms see
gastropod shell
The gastropod shell is part of the body of many gastropods, including snails, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium ...
.
The body of this semi-slug is too large to be contained in the very flat and depressed ear-shaped shell. The shell body whorl is ¾ of the total breadth viewed from above. It is very thin, fragile and transparent. Shell colour is greenish or yellowish. The shell aperture has a mouth membrane which runs from the umbilicus along the inside of the outer lip. The animal is pale to dark grey or black, paler forms have large dark grey areas. The mantle lobe is very large. Genitalia:Penis with appendix, joins vagina below the insertion of spermatheca duct.
Distribution and habitat
This species is known to occur in Brittany, the French Pyrenees, Andorra, Spain and southwestern Ireland. This is called a
Lusitanian distribution
In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but considerably separated from each other geographically. The causes are varied and might demonstrate either the expansion or contraction of a s ...
and was at one time thought to represent the survival of species in an ice-free land mass that served as a
refugium during the last ice age. This theory has now been discredited as Ireland is thought to have been entirely covered by ice during the height of the
Quaternary
The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...
glaciation. It now seems likely that these species were re-introduced into Ireland after the last glaciation, probably accidentally with human migration in the late
Paleolithic
The Paleolithic or Palaeolithic ( years ago) ( ), also called the Old Stone Age (), is a period in human prehistory that is distinguished by the original development of stone tools, and which represents almost the entire period of human prehist ...
or early
Mesolithic
The Mesolithic (Ancient Greek language, Greek: μέσος, ''mesos'' 'middle' + λίθος, ''lithos'' 'stone') or Middle Stone Age is the Old World archaeological period between the Upper Paleolithic and the Neolithic. The term Epipaleolithic i ...
.
It typically inhabits humid and shady places, between rocks, or in Ireland in woodland amongst moist ground litter, usually on non-calcareous soils. It is not usually found in areas grazed by livestock.
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References
External links
''Semilimax pyrenaicus''
at Animalbase
AnimalBase is a project brought to life in 2004 and is maintained by the University of Göttingen, Germany. The goal of the AnimalBase project is to digitize early zoological literature, provide copyright-free open access to zoological works, and p ...
taxonomy,short description, distribution, biology,status (threats), images
* Info on Irish occurrence
*Fauna Europaea
Fauna Europaea is a database of the scientific names and distribution of all living multicellular European land and fresh-water animals. It serves as a standard taxonomic source for animal taxonomy within the Pan-European Species directories Infr ...
br>Search
Distribution
* Photo of live individual at
{{Taxonbar, from=Q7449437
Vitrinidae
Gastropods described in 1821