Gastropods · Nudibranchia · Chromodorididae

Anna's Chromodoris

Chromodoris annae

Not Evaluated

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

A nudibranch with a deep blue mantle edged in orange and marked with lengthwise black lines, much photographed by divers. It feeds exclusively on sponges and is hermaphroditic, like the rest of the nudibranchs.

Size

3 cm – 5 cm

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

24countries 87dive sites

Fun facts

It stores in its mantle the toxic compounds of the sponges it eats and advertises that toxicity with its striking colours: a case of aposematic colouration.
The plumes at its rear are gills, and the horns on its head (the rhinophores) are chemosensory organs.
It does not make its own chemical defence: it takes secondary metabolites from the sponges it eats and concentrates them in glands along the mantle edge, ready to be secreted if it is attacked.
Its striking colours — blue, black and orange — are aposematic: they advertise that toxicity.
Several species in the genus share very similar colour patterns despite not being close relatives, a case of mimicry between equally toxic species.
Chromodorids tend to be highly specialised on a single sponge species.
Like all nudibranchs, it is a simultaneous hermaphrodite and mates side by side, exchanging sperm in both directions.