Homberg's Plumed Nudibranch

• The adults camouflage themselves by taking on the shade of the soft coral colony they live on and feed from.
• The largest individuals exceed 20 cm, an extraordinary size for a cold-water nudibranch.
• It is the largest nudibranch in the British Isles: it reaches 20 cm.
• It eats almost nothing but the polyps of the soft coral known as dead man's fingers. When it arrives, the coral retracts all its polyps in an attempt to protect itself.
• As a juvenile it is white and blends perfectly into the coral; as it grows it darkens and hides in crevices and beneath overhangs.
• Its juveniles were long considered a separate species, Tritonia alba, partly because the radula changes shape as the animal grows.
• The tubercles on its back secrete an irritant compound: handling it can raise blisters on the skin, which is exceptional among nudibranchs.
• Despite its size, its life cycle is annual.

Skeleton type

Invertebrate - no rigid skeleton (mollusc)

Habitat and environment

Rocky bottoms of the north-eastern Atlantic with octocoral colonies

Litter / clutch size

Thousands of eggs in a coiled ribbon

Sources consulted: Cuvier (1803) · Thompson y Brown (1984), Biology of Opisthobranch Molluscs · Marine Life Information Network · anatomia de Gastropoda

The pins mark the parks where its presence is documented.