sea slugs - plants or animals?

March 23, 2001
From: Tom Mackillop

To who it concerns
I am in yr.11 at school and in our biology class we have some dispute over the kingdom into which sea slugs fall into, animal or plant. I would appriciate hearing from anyone who could set us on the right track
Tom Mackillop

Mackillop, T., 2001 (Mar 23) sea slugs - plants or animals?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Tom,
One of the main differences between plants and animals is that plants produce their own food by chemical reactions while animals obtain their nutrients by eating existing organic matter. Sea Slugs are a specialised group of snails (Phylum Mollusca), and are definitely animals. Some are herbivores (plant-eaters) while others are carnivores, often eating only a very specialised group of animals.

There are two fascinating groups of sea slugs, which I have called 'Solar Powered' because they have become very plant-like in their behaviour. Have a look at the Solar Powered Slugs Page for some background information on these animals. Perhaps they are what made you wonder whether they are in fact plants?

Have a look also at the messages below yours on this page as there is more information with each message. If you click on any underlined word it will take you to another relevant page.
Best wishes,
Bill Rudman

Rudman, W.B., 2001 (Mar 23). Comment on sea slugs - plants or animals? by Tom Mackillop. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

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