The Great Barrier Reef Library

A comprehensive guide to The Great Barrier Reef

Gastropoda – Snails, slugs and nudibranchs


By on November 11, 2017

Gastropoda is an extremely common Class and the most numerous within the Phylum Mollusca. They are found worldwide in freshwater as well as the oceans. They are even numerous on land in damp conditions. You will be familiar with many, such as the snails and slugs that are found in your garden, but they also include Marine Shells, Nudibranchs and Snails.

Most Gastropods have a large muscular foot, a distinctive head, complete with eyes, sensory tentacles and body organs held within the mantle. Many are covered by a protective shell, although some have a smaller, internal one. Others, such as The Nudibranchs have no shell at all.

As far as Molluscs go, Gastropoda are relatively mobile and active. They are driven by the search for food or a mate. Therefore, they have eyes, as well as other sensory organs. Whilst they lack a brain for interpreting these senses, they do have a rather complicated net of nerves in their head. Most Gastropods prefer to use chemical senses over eyesight. Just below the gills, in the mantle cavity, is an organ called The Osphradium, which senses the chemical inputs.

Most Gastropods are herbivores, although there are also many predators in this Class.

You can find a list of all of the Orders of Gastropoda found on The Great Barrier Reef, below.1

Order – Fancy science word used to group organisms with similar characteristics

Nudibranchia Nudibranchia – Nudibranchs

To be updated