Limacus flavus, known commonly as the cellar slug, the yellow slug, or the tawny garden slug, is a large species of air-breathing land slug, a terrestrial pulmonate gastropod mollusc in the family Limacidae.

Description and identification

thumb|left |Genitalia of the two Limacus species; bc = bursa copulatrix, p = penis, ovi = free oviduct

Limacus flavus and L. maculatus are both large species of slug (up to 130 mm) with a yellow colouration, mottled with darker blotches; the tentacles are blue-grey. Juveniles are much darker. Like other limacid slugs, the tail is pointed and the pneumostome lies in the hind part of the mantle. The mucus is yellow or colourless.

External characters proposed to distinguish the species appear to be less consistent but may be useful in particular regions or as a preliminary indication. For instance in the British Isles L. flavus differs from L. maculatus in having a pale line along the midline of the back, but this is not consistenly present in Ukrainian populations. are contradicted by British and Dutch specimens.

In the British Isles, apparently hybridisation has given rise to individuals with the genital characters of L. flavus but the mitochondrial DNA sequences of L. maculatus.

right|thumb|150px|Drawing of [[Reproductive system of gastropods|reproductive system of Limacus flavus.]]

Distribution

Limacus flavus is most likely to be native in some area around the Mediterranean but has evidently been spread by man much more widely, so a genetic analysis would be necessary to be more certain of its origin. It has long occurred throughout most of Europe (certainly in Britain in the 17th century

In Ukraine it is expanding its range in the 21st century, possibly associated with global warming. In Central Europe, the cleaning up and sealing of old cellars has led to it being considered threatened, but night searching has suggested that it remains more widespread than at one time feared. In Ireland and Great Britain it appears to be being displaced by its congener L. maculatus. and vegetables.

Habitat

This species is strongly associated with human habitation, and is usually found in damp areas such as cellars, kitchens, and gardens or under stones. Generally speaking it is only seen at night, because it is nocturnal. Thus often it goes unnoticed and people are unaware of how (relatively) common the species is.

Parasites

Parasites of Limacus flavus include the nematode Angiostoma spiridonovi and the slug mite Riccardoella oudemansi.

References

  • Limax flavus at Animalbase taxonomy, short description, distribution, biology, status (threats), images