Rhinophore

A rhinophore is one of a pair of club-shaped structures which are the most prominent part of the external head anatomy of a group of sea slugs, marine gastropod opisthobranch mollusks in the order Nudibranchia, the nudibranchs, specifically the dorid nudibranchs.

Rhinophores are scent or taste receptors, also known as chemosensory organs. The first part of the word rhinophore is from the classical Greek word for nose, the second part means to carry or to bear; this relates to the rhinophore's function as an organ of "smell".

The "scents" detected by rhinophores are chemicals dissolved in the sea water. The fine structure of the rhinophore provides a large surface area so that chemical detection is maximized. This allows the nudibranch to stay close to its food source, which is also the living substrate it preferentially inhabits.

To protect the prominent rhinophores against nibbling by predators including fish, most species of dorid nudibranchs are able to withdraw their rhinophores into a pocket beneath the skin.

References

* [http://www.seaslugforum.net/factsheet.cfm?base=rhinonud Sea Slug Forum]