A slug senses up with tiny stones.

Inside two fluid-filled organs, mineral grains press on sensory hairs as gravity pulls them. The signal helps the animal orient itself.

Gosse described the little capsules as ears. Today, we recognise their role in balance.

A slug senses up with tiny stones.

A slug beside two enlarged schematic balance organs. Mineral grains press on sensory hairs under gravity; the second panel shows how a tilted organ changes the contact pattern.

A simplified explanation of the statocyst, a gravity-sensing organ. Capsule size and positions in the enlarged diagrams are illustrative.

Leopard Slug (Limax maximus) in Whitefish, MT, USA

A leopard slug (Limax maximus), a living terrestrial gastropod. The internal balance organs are too small to see here.

A slug senses up with tiny stones.

Explore related topics