Rostanga rubra (Risso, 1818)

Rostanga rubra

Description: The colour of this nudibranch varies from bright red to pale orange-yellow with tiny black spots scattered on its dorsum. The mantle bears many minute tubercles and defensive spicules. There is a characteristic pale patch between the rhinophores. Adults may attain a body length of up to 15mm.

Habitat: Feeds upon the red sponges Ophlitaspongia seriata and Microciona atrasanguinea. It is most often found on the low shore or in the shallow subtidal. At St. Kilda it feeds on Ophlitaspongia kildensis in the sublittoral.

Distribution: R. rubra has been found around the Orkneys and at St. Abbs Head on the North Sea coast as well as on the south and west coasts of the British Isles. Further distribution from Norway south to the Mediterranean.

Similar Species: Unlikely to be confused with other British dorids except perhaps with the red variety of Archidoris pseudoargus.

Key Identification Features:

Distribution Map: NBN map : National Biodiversity Network mapping facility, data for UK.

WoRMS: Species record : World Register of Marine Species.

iNaturalist: Species account : iNaturalist World Species Observations database

 Picton, B.E. & Morrow, C.C. (2016). Rostanga rubra (Risso, 1818). [In] Encyclopedia of Marine Life of Britain and Ireland. Accessed on 2024-05-22

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