''Deroceras panormitanum'' 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

slug Slug, or land slug, is a common name for any apparently shell-less Terrestrial mollusc, terrestrial gastropod mollusc. The word ''slug'' is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced ...

, a

terrestrial Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on o ...

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 ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

in the family Agriolimacidae. ''Deroceras panormitanum'' ''

sensu stricto ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular c ...

'' ("in the strict sense") is common on Sicily and Malta, but also occurs sporadically as an introduction elsewhere in Western Europe and

Macaronesia Macaronesia (; ) is a collection of four volcanic archipelagos in the Atlantic Ocean#North Atlantic, North Atlantic Ocean, off the coast of North Africa and Europe. Each archipelago is made up of a number of list of islands in the Atlantic Oc ...

. Before 2011, this name was also applied to what turned out to be a distinct species, '' Deroceras invadens'', a species which has spread widely around the world and is often a pest.

Synonymy

''Deroceras panormitanum'' was described from Palermo in Sicily. It is now widely accepted that ''Deroceras pollonerae'' also described from Palermo, ''Deroceras caruanae'' described from Valletta on Malta, and ''Deroceras dubium'' from Malta are the same species. Reise et al. also synonymised ''Deroceras giustianum'' from NW Sicily but considered the status of further similar taxa from this general region as uncertain. Now that '' Deroceras invadens'' has been recognised as distinct, the morphological variation within ''Deroceras panormitanum'' sensu stricto is not as great as once thought.

Description

The skin and flesh of ''Deroceras panormitanum'' is watery and fairly transparent. The skin colour varies between pale grey, brown, and black. The mucus is colourless. Externally, ''Deroceras panormitanum'' is impossible to distinguish from '' Deroceras invadens'' and ''Deroceras golcheri'', which occur in the same islands, and from a variety of other ''Deroceras'' species occurring elsewhere. Internally the penis of ''Deroceras panormitanum'' has two side pockets (penial caecum and penial lobe), as in ''Deroceras invadens'' but unlike in ''Deroceras golcheri'' or related forms on Sicily. In ''Deroceras panormitanum'' the caecum is more tapering and pointed than in ''Deroceras invadens''. Whereas in ''Deroceras invadens'' the retractor muscle attaches directly to a point on the penis between the caecum and lobe, in ''Deroceras panormitanum'' it attaches first to the lobe. Also the penial glands often appear more knobbly than in ''Deroceras invadens''. And inside the penis, between the distal and proximal parts, is a small flap that is absent in other species. Deroceras panormitanum penis

Reise et al. detailed the mating behaviour and compared it with that of ''Deroceras invadens'' and ''Deroceras golcheri''.

Distribution

Sicily Sicily (Italian language, Italian and ), officially the Sicilian Region (), is an island in the central Mediterranean Sea, south of the Italian Peninsula in continental Europe and is one of the 20 regions of Italy, regions of Italy. With 4. ...

and

Malta Malta, officially the Republic of Malta, is an island country in Southern Europe located in the Mediterranean Sea, between Sicily and North Africa. It consists of an archipelago south of Italy, east of Tunisia, and north of Libya. The two ...

this species is widespread and presumed to be native. It has now been recorded also as presumed introductions at one site in northern

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

, on the island of

Mallorca Mallorca, or Majorca, is the largest of the Balearic Islands, which are part of Spain, and the List of islands in the Mediterranean#By area, seventh largest island in the Mediterranean Sea. The capital of the island, Palma, Majorca, Palma, i ...

, in Estremadura and

Ribatejo The Ribatejo () is the most central of the traditional provinces of Portugal, with no coastline or border with Spain. The region is crossed by the Tagus river (''Ribatejo'' translates to "upper Tagus", or more precisely, "up the Tagus" relative ...

in mainland Portugal, at two neighbouring sites on

Madeira Madeira ( ; ), officially the Autonomous Region of Madeira (), is an autonomous Regions of Portugal, autonomous region of Portugal. It is an archipelago situated in the North Atlantic Ocean, in the region of Macaronesia, just under north of ...

and on produce originating from the

Azores The Azores ( , , ; , ), officially the Autonomous Region of the Azores (), is one of the two autonomous regions of Portugal (along with Madeira). It is an archipelago composed of nine volcanic islands in the Macaronesia region of the North Atl ...

, at three sites in France, and within the British Isles at two sites in South Wales, two in England and at one site in Ireland.

References

External links

''Deroceras panormitanum''
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 {{Taxonbar, from=Q917407 Agriolimacidae Gastropods described in 1882 Gastropods of Europe