Leopard Slug

Giant Slug or Leopard Slug (Limax maximus) is a European species now found in North America and Australia. It is in the family Limacidae which is comprised of the keel back slugs. Keel back slugs are longer and thinner than the round back slugs that make up the family Arionidae. Keel back slugs also possess an internal shell under their mantle shield. The mantle shield is the section of the slug closest to their “head.” On the slug’s right side is their respiratory opening.

Slug anatomy

Front of Leopard Slug

I found Leopard Slugs at the Royal Oak Arboretum behind the Senior Center in Royal Oak, Michigan. They come out when it is getting dark and are active throughout the night. They are 10-15cm (4-6 inches) long. Eating mainly fungus, dead vegetation, and other slugs they are not normally garden pests unless the population is large. I was surprised at how fast they moved. I timed one crossing a 1.5m (6 foot) path in 15 seconds.

Leopard Slug at full stretch

For more information on this slug and other gastropods check out Robert Nordsieck’s great website The Living World of Molluscs. The Leopard Slugs are here.

Copyright 2014 by Donald Drife

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