Description: The cerata of this nudibranch are short and neatly arranged. The entire body and cerata are usually red in colour, but occasional brown or greenish-brown individuals have been reported, the colour is probably influenced by diet. The rhinophores have conspicuous white tips which are clearly differentiated from the rest of the rhinophore. The oral tentacles and cerata also have white tips.

Habitat: A rather scarce species in the British Isles, usually found beneath rocks in the intertidal, but occasionally in the sublittoral. This species has large eyes and is more active at night, at least in captivity. It feeds on Sagartiid anemones, especially on Sagartia elegans. The spawn is a spiral thread with scalloped sections separated by breaks.

Distribution: Most British Isles records are from Ireland, where the species has been reported from Lough Hyne, Galway Bay and Donegal Bay. There are recent records from the Calf of Man and Loch Sween, indicating that the apparent absence of this species from SW England is probably an anomaly.

Key Identification Features:

• Red coloration throughout body with little surface pigment.
• Conspicuous well-defined white tips to the rhinophores.

Distribution Map from NBN: Aeolidiella sanguinea at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Aeolidiella sanguinea at iNaturalist World Species Observations database.

WoRMS: Aeolidiella sanguinea at World Register of Marine Species. Accepted name: Aeolidiella sanguinea (Norman, 1877). AphiaID: 138714.

Classification: Biota; Animalia; Mollusca; Gastropoda; Heterobranchia; Euthyneura; Ringipleura; Nudipleura; Nudibranchia; Cladobranchia; Aeolidioidea; Aeolidiidae; Aeolidiella