''Laevicaulis alte'', or the tropical leatherleaf, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

land

slug Slug, or land slug, is a common name for any apparently shell-less 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 shell, or only a smal ...

, a

terrestrial Terrestrial refers to things related to land or the planet Earth. 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 or near the ground, as opposed to ...

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 includ ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the family

Veronicellidae The Veronicellidae, also known by their common name the leatherleaf slugs, are a family of pulmonate terrestrial slugs. The herbivorous molluscs occur mainly in the tropical and subtropical areas of America, Asia and Africa. They act as intermed ...

, the leatherleaf slugs.

Description

''Laevicaulis alte'' is a round, dark-coloured slug with no shell, long. Its skin is slightly tuberculated. The central

keel The keel is the bottom-most longitudinal structural element on a vessel. On some sailboats, it may have a hydrodynamic and counterbalancing purpose, as well. As the laying down of the keel is the initial step in the construction of a ship, in Br ...

is beige in colour. This slug has a unique, very narrow foot; juvenile specimens have a foot wide and adult specimens have a foot that is only wide. The

tentacle In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

s are small, long, and they are only rarely extended beyond the edge of the mantle.

Parasites

This slug is an intermediate host for ''

Angiostrongylus cantonensis ''Angiostrongylus cantonensis'' is a parasitic nematode (roundworm) that causes angiostrongyliasis, the most common cause of eosinophilic meningitis in Southeast Asia and the Pacific Basin. The nematode commonly resides in the pulmonary arteries ...

'', the rat lungworm, a round worm, the most common cause of eosinophilic meningoencephalitis.

Predators

''Laevicaulis alte'' is eaten by the frog '' Rana tigrina''.

Distribution

The species is probably indigenous to

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

, both western Africa and eastern Africa, particularly

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and ...

.Rowson B., Warren B. H. & Ngereza C. F. (2010). "Terrestrial molluscs of Pemba Island, Zanzibar, Tanzania, and its status as an "oceanic" island". ''

ZooKeys ''ZooKeys'' is a peer-reviewed open access scientific journal covering zoological taxonomy, phylogeny, and biogeography. It was established in 2008 and the editor-in-chief is Terry Erwin (Smithsonian Institution). It is published by Pensoft Publ ...

'' 70: 1-39. It has been introduced and has become an

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

in the following areas: * Southern

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

Pratas Island Pratas Island,, United States National Geospatial-Intelligence Agency also known as the Tungsha Islands or the Dongsha Islands (), is a coral island situated in the northern part of the South China Sea administered as part of Cijin District, Kao ...

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort ...

Wu S.-P., Hwang C.-C., Huang H.-M., Chang H.-W., Lin Y.-S. & Lee P.-F. (2007).
Land Molluscan Fauna of the Dongsha Island with Twenty New Recorded Species
. ''Taiwania'' 52(2): 145–151
Original
*

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

(

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

) * Islands in the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

(since 1889) *

Samoa Samoa, officially the Independent State of Samoa; sm, Sāmoa, and until 1997 known as Western Samoa, is a Polynesian island country consisting of two main islands (Savai'i and Upolu); two smaller, inhabited islands (Manono Island, Manono an ...

The species is already established in the USA, and is considered to represent a potentially serious threat as a pest, an

which could negatively affect agriculture, natural ecosystems, human health or commerce. Therefore, it has been suggested that this species be given top national

quarantine A quarantine is a restriction on the movement of people, animals and goods which is intended to prevent the spread of disease or pests. It is often used in connection to disease and illness, preventing the movement of those who may have been ...

significance in the USA.Cowie R. H., Dillon R. T., Robinson D. G. & Smith J. W. (2009). "Alien non-marine snails and slugs of priority quarantine importance in the United States: A preliminary risk assessment". ''American Malacological Bulletin'' 27: 113–132
PDF

Habitat

''Laevicaulis alte'' lives in dry areas, mostly at lower altitudes.

Life cycle

The slug hatches from eggs. ''Laevicaulis alte'' has several adaptations for living in dry conditions: a rounded shape with as small as possible surface area, and a narrow foot to reduce evaporation. Juvenile specimens search for food nearly always at night, and stay buried in the soil during the day. Larger specimens are active during the day sometimes. The slug can grow up from to approximately in length in 7 months.

References

External links

articles at PubMed

Distribution in United States

In English
an
in Chinese

Images

photo
(In Japanese)
''Laevicaulis alte''
at
Samoan Snail Project

(Japanese)
Photo
(Japanese)

(Japanese)

(Japanese)

Genome

Sequences 18S rRNA

Vernacular names
{{Taxonbar, from=Q3170495 Veronicellidae Gastropods described in 1822