Sensory organs of gastropods

The sensory organs of gastropods (snails and slugs) include olfactory organs, eyes, and mechanoreceptors. Gastropods have no sense of hearing.

In terrestrial gastropods the most important sensory organs are the olfactory organs which are located on the tips of the 4 tentacles.

In opisthobranch marine gastropods, the chemosensory organs are two protruding structures on top of the head. These are known as rhinophores.

An opisthobranch sea slug Navanax inermis has chemoreceptors on the sides of its mouth to track mucopolysaccharides in the slime trails of prey, and of potential mates.

The freshwater snail Bithynia tentaculata is capable of detecting the presence of molluscivorous (mollusk-eating) leeches through chemoreception, and of closing its operculum to avoid predation.

The deepwater snail Bathynerita naticoidea can detect mussel beds containing the mussel Bathymodiolus childressi, because it is attracted to water that has cues in it from this species of mussel.

Some terrestrial gastropods can track the odor of food using their tentacles (tropotaxis) and the wind (anemotaxis).

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