Limax maximus

Native to: S and W Europe (mainly in disturbed areas to the north) (Rollo & Wellington 1979), Asia Minor, and Algeria (Thompson 2008).

Non-native in: South Africa, N America, Australia, New Zealand (Herbert 1997), Japan (Azuma 1982).

Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) This species is fairly cosmopolitan globally but probably has a European origin in Europe, North Africa, and Asia Minor. It has been introduced widely around the world including Asia Minor, Australia, Canada, Europe, Mexico, New Zealand, the United States (including Hawaii and Alaska), Africa, and South America.

This slug is an introduced species in North America and other temperate regions of the world.

Biogeographic Regions: nearctic (Introduced )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Exotic

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Exotic

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Spotted garden slugs can attain at least 6 inches in length. They vary in color from yellowish-gray to brown with black spots on the mantle near the head and black stripes extending along the rest of the body. The tail area is wrinkled. There is a pneumostome or breathing pore on the back part of the mantle that this slug uses to breathe.

Range length: 15.24 (high) cm.

Other Physical Features: bilateral symmetry

Sexual Dimorphism: sexes alike

External: Light brown to gray body; multiple dark longitudinal stripes often breaking into spots on dorsum; mantle marbled; tentacles red-brown; whitish sole; clear mucus (Rollo & Wellington 1979).

Internal: Internal shell 11 x 7 mm; long, narrow, pale ovotestis; long, convoluted penis has an internal fold and a "comb" toward its apex; no rectal caecum (Quick 1960; Kerney & Cameron 1979).

Similar to L. cereoniger but no spotted tentacles or dark outer sections of sole (Rollo & Wellington 1979), smaller tubercles, shorter keel, larger jaw and internal shell, and penis smaller and narrows toward its base (Quick 1960; Sysoev & Schileyko, 2009).

Juveniles similar to Lehmannia marginatus and Ambigolimax valentianus except L. maximus has less mucus, no lyre banding on the mantle (Rollo & Wellington 1979), and bands on the sides (Quick 1960).

Eggs: 5.0 x 5.5 mm eggs, translucent and amber(Quick 1960).

Juveniles: light gray with side bands and light pink-gray tentacles at hatching; body bands and mantle coloration appears in 2-3 weeks (Quick 1960).

100-200 mm long extended (Rollo & Wellington 1979).

Limax cereoniger; Lehmannia marginatus and Ambigolimax valentianus relative to juveniles

Spotted garden slugs are found in moist places in fields, woods, and gardens. They inhabit damp ground under wood, rocks, vegetation, and other shaded areas.

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: forest

Habitat Type: Terrestrial

Comments: This species is common in gardens and buildings, and margins of native forests, but does not seem to penetrate far into undistrubed forests, although it can be abundant in modified forest remnants and secondary forests (Barker, 1999).

Outsides of buildings, waste piles (Cook & Radford 1988), forests, hedgerows, gardens (Rollo & Wellington 1979).

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Spotted garden slugs will eat fungi, decaying organic matter, and plants.

Plant Foods: leaves; lichens

Other Foods: fungus; detritus

Comments: This nocturnal slug feeds primarily on decaying plant material and fungi, but because it shows aggresive behavior towards other slugs, it is often erroneously regarded as a predator (Barker, 1999).

Feeds on dead plants, fungus, domestic waste, carrion, and garden and crop plants (Herbert 2010). Prefers fungi and dead plants to live plants; eats oatmeal in captivity (Quick 1960).

This slug may help cycle nutrients in soil via its feeding activities.

They may be an intermediate host for trematodes and nematode worms.

Certain kinds of protozoans may be parasitic in them.

Ecosystem Impact: biodegradation

Commensal/Parasitic Species:

• ciliated protozoans

When irritated, spotted garden slugs will secrete a colorless mucus. A slug may lift its tail and vibrate it back and forth as a means of scaring a potential predator. It may clamp its mantle to the ground to protect its head. To scare away predators, it may even squirt blood through its breathing hole!

Known Predators:

• Gastropoda
• Thamnophis sirtalis
• Anseriformes
• other Aves 
• Talpidae
• Soricidae
• other small Mammalia 
• Anura

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: > 300

Comments: This species was first recorded in Hawaii either in 1931 or 1949 (Cowie, 1997) and has become established on Hawaii. In a recent survey, it was found in the Pua Akala region, southern part of Hakalua Forest National Wildlife Refuge, on the windward slopes of Mauna Kea, elevation 5150-6240 feet, Hawaii, Hawaiian Islands (Howarth et al., 2003). It had been documented historically in Colorado (Cockerell, 1927) but recent (2008) specimens exist in the University of Colorado Museum. In California, it occurs in 13 counties: Alameda, Calaveras, Humboldt, Kern, Los Angeles, Marin, Orange, Sacramento, San Bernardino, San Diego, San Francisco, Santa Barbara (incl. Santa Cruz Island), and Santa Clara (McDonnell et al., 2009). In New York, Hotopp and Pearce (2007) report it from 9 counties in the eastern, southeastern and far western parts of the state as an exotic. Forsyth (2005) documented it in the Upper Fraser Basin of central British Columbia in a single area in Quesnel but it is now widespread in southern British Columbia. Most recently, it was discovered in the Ktunaxa Traditional Territory in southeastern British Columbia (which extends from near Canada - U.S. border north to about 50 km north of Cranbrook) (Ovaska and Sopuck, 2009).

>1,000,000 individuals

L. maximus is an aggressive slug species both in the wild and the lab, especially in high densities, often killing and eating other slugs both of their own and other species (Rollo & Wellington 1979).

Defends itself through tail-wagging (and slapping) and quick fleeing (Rollo & Wellington 1979).

Homes to shelter (Cook 1979).

Engages in a conspicuous form of mating. A pair of L. maximus hangs from a long mucus thread, their bodies and blue-white penes encircle each other, and they exchange sperm on the ends of their penes (Quick 1960).

Eggs are approximately 1/4 inch in diameter, and when first laid, they are colorless and transparent. Gradually, the eggs become cloudy, resembling small pearls. Development is direct whereby larval stages occur within the egg, and eventually, tiny slugs emerge from the eggs. Limax becomes sexually mature in two years.

Lives 3-4 years. Eggs are laid in early spring and fall (Quick 1960).

This slug may live up to three years.

A pair of slugs will hang by a mucus string from a branch while they mate.

Egg size in late summer is smaller than egg size in autumn. In addition, clutch sizes are larger in summer than in autumn. In the autumn, a clutch size may be 50 to 130 eggs. Spotted garden slugs may exhibit aggression toward other slugs or snails when shelter sites for breeding are scarce.

Range number of offspring: 130.0 (high) .

Key Reproductive Features: simultaneous hermaphrodite; sequential hermaphrodite (Protandrous ); sexual ; fertilization (Internal ); oviparous

Parental Investment: no parental involvement

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 10
Specimens with Barcodes: 21
Species With Barcodes: 1

The following is a representative barcode sequence, the centroid of all available sequences for this species.

There are 9 barcode sequences available from BOLD and GenBank.  Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen and other sequences.

Download FASTA File

Canada

Rounded National Status Rank: NNA - Not Applicable

United States

Rounded National Status Rank: NNA - Not Applicable

Rounded Global Status Rank: G5 - Secure

Reasons: This species is fairly cosmopolitan globally but probably has a European origin in Europe, North Africa, and Asia Minor. It has been introduced widely around the world including Asia Minor, Australia, Canada, Europe, Mexico, New Zealand, the United States (including Hawaii and Alaska), Africa, and South America.

This slug has been known to damage gardens. It may be an intermediate host for some trematode and nematode worms which can harm our pets.

Negative Impacts: crop pest; causes or carries domestic animal disease

This slug may contribute to regeneration of soil because of its eating habits.