Gastropods · Nudibranchia · Tritoniidae

Homberg's Plumed Nudibranch

Tritonia hombergii

Not Evaluated

It has not yet been assessed against the IUCN criteria. See full glossary

The largest nudibranch of the north-eastern Atlantic, pink to brown and with rows of branched appendages along its sides. It feeds almost exclusively on the octocoral Alcyonium digitatum, known as dead man's fingers, on which it spends much of its life.

Size

5 cm – 20 cm

Lifespan

1 years

Diet

Carnivore

Feeds mainly on other animals.

Social structure

Solitary

Lives and hunts alone, joining others only to breed.

Sighting difficulty

Unknown

OceanCarnivore Solitary Ocean Mollusc

13countries 22parks

Fun facts

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.

Life cycle & biology

Habitat & 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