Leopard Slug

Limax maximus

Summary 4

Limax maximus (literally, "great slug"), known by the common names great grey slug and leopard slug, is a species of slug in the family Limacidae, the keeled slugs. It is among the largest keeled slugs, Limax cinereoniger being the largest.

Description 5

The body length of the adult is 10-20 cm (4-8 in).

The greater part of the body is rounded, but there is a short keel on its tail, with about 48 longitudinal rows of elongate, detached tubercles. The body color is pale-grey, ash-colored, brownish or sometimes yellowish-white. The body is longitudinally streaked or spotted with black. The pattern of spotting is variable. The shield is always black-spotted. The sole of the foot is a uniform ash or yellowish-ash color. The foot-fringe is pale, with a row of minute submarginal blackish tubercles.

The tentacles are very long and slender. The reproductive pore is near the base of the right upper tentacle.

The shield is oblong, about one third of the total length of the animal. The shield is rounded in front, angular behind, and forming an angle of about 80 degrees when in motion, usually of a similar tint to the body, but boldly marbled or maculate with black, somewhat concentrically and interruptedly ridged around a sub-posterior nucleus.

The pneumostome is just posterior to the midpoint of the mantle, as it is in all Limacidae.

The mucus is colorless and iridescent, and not very adhesive.

Although color varieties have no actual taxonomic significance, a large number of color varieties have been described, prominent among them being the varieties serpentinus, vulgaris, cellarius (typical), johnstoni, maculatus, ferrussaci, obscurus, fasciatus and rufescens, of Alfred Moquin-Tandon, and cornaliee, of Pini.

The shell of Limax maximus is reduced and internal, under the shield. The occurrence of this internal shell was known to Pliny the Elder; the shell was used by the ancient physicians for the sake of its carbonate of lime.

The calcitic shell is situated beneath the hinder part of the shield, and is perceptible through the skin. The color of the shell is whitish. The shape of the shell is oblong-oval and thin, slightly convex above, and correspondingly concave beneath, with a membranous margin. The apex or nucleus is at the posterior margin but inclined towards the left side, and forming the apophysis by which the shell is organically attached to the animal. The length of the shell is 13 mm (1/2 inch) and the width of the shell is 7 mm (1/4 inch). Shells of different Limacidae species are undiagnostic: in other words, they are not helpful for identification purpose.

Digestive system: The formula of the radula is: 62-73/ × 138-157. The intestine has six convolutions and is without a caecum. Of the six convolutions of the intestine, four are imbedded in the liver, and two hang freely in the body cavity.

The nervous system is composed of the typical ganglia. The pedal ganglia are placed beneath the radula sac and joined together by an anterior and a posterior commissure. The abdominal ganglion lies a little to the right of the median line. The visceral ganglia occupy the angle between the lingual sheath and the oesophagus and the buccal ganglia are widely separated but joined together by a commissure nearly as thick as the ganglia themselves.

Reproductive system: The hermaphrodite gland (HG) is elongated and large, and is connected with spermoviduct (SD) by means of the hermaphrodite duct (HD) which takes its course through a portion of the albumen gland (AG). The spermoviduct is thick and well convoluted, and separates further down into a vas deferens or sperm-duct (VD) and an oviduct (OV). The former opens into the upper end of a very long penis (P), to which a strong retractor muscle (PRM) is attached. The lower portion of the penis unites with that of the oviduct at the genital orifice, so that there is no vestibule. The receptaculum seminis (RS) opens into the lower end of the penis near the junction of the two ducts.

Habitat 5

The slug is almost always found near human habitation — usually in lawns, gardens, cellars or in other damp areas.

This species is not gregarious. It frequents gardens, damp and shady hedgerows and woods, hiding during the day beneath stones, under fallen trees, or other obscure and damp places. It does however exhibit a decided preference for the vicinity of human habitations, and readily takes up its abode in damp cellars or outbuildings.

In Ireland, this predilection for human dwellings is not exhibited, and the species is restricted to woods and other similar places. It may even be met almost within a high-water mark on the seashore.

Sources and Credits

  1. (c) cmain16, some rights reserved (CC BY-NC), uploaded by cmain16
  2. (c) ahmed m, some rights reserved (CC BY-NC-ND), https://www.flickr.com/photos/124633205@N02/14549538061/
  3. (c) Tony Alter, some rights reserved (CC BY), https://www.flickr.com/photos/78428166@N00/7870003812/
  4. Adapted by kmarie333 from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Limax_maximus
  5. (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Limax_maximus

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