Leopard Slug

• Its mating is among the most spectacular in the animal world: the two animals hang in mid-air from a thread of mucus and unfurl bluish copulatory organs that twine around one another.
• Beneath the mantle shield it keeps a vestigial internal shell of 13 to 15 mm, all that is left of the shell its lineage lost.
• It is fast enough to hunt other slugs, and uses the previous night's slime trail to find its way back to its refuge and to the food it left half-eaten.
• Its mating is among the most spectacular in the animal kingdom: the pair climbs a branch or a wall, lowers itself on a mucus thread of up to 40 cm and, hanging in mid-air, unfurls translucent, bluish copulatory organs that entwine in a spiral. The scene lasts for hours.
• It is hermaphroditic, so both individuals exchange sperm in that same mating.
• It is above all a scavenger and fungus-eater, not a herbivore: it eats fungi, rotting plant matter and other slugs, which is why it is not a serious garden pest, unlike the Spanish slug.
• It is in fact a predator: it pursues and devours other slugs, including the harmful species.
• It returns to its shelter each dawn by following its own mucus trail, and occupies the same hiding place for long periods.
• Its slime trails on cellar walls are its most familiar sign.

Skeleton type

Invertebrate - gastropod mollusc with no external shell (it retains a vestigial internal shell)

Habitat & environment

Highly varied, both natural and man-made: damp woodland, gardens, cellars and urban areas. Common across much of Europe including Corsica, Sardinia and the Balearics; scarcer in the south of the Iberian Peninsula. In Switzerland it reaches 1,900 m

Litter / clutch size

It is a cross-fertilising hermaphrodite. The pair mates hanging in the air from a thick thread of mucus suspended from a branch, intertwining their large white genital organs

Sources consulted: IUCN Red List; Asturnatura; Wikipedia (Limax maximus); Botanical-online; El medi natural del Bages i del Moianès

Best time: Rainy nights and days; by day it stays hidden in its usual refuge