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How does it look like?
It is a shelled mollusc, flattened and circular in shape, with irregular dark brown spots randomly distributed all over its body. It can measure between 5 and 15 centimetres long when at rest. It has a crown of 6 to 9 tripinnate gills about 1cm long on the back of the dorsal area surrounding the anus. On the head there is a pair of rhinophores with unbranched blades. On the belly is the foot, which is very narrow and not visible because it is hidden under the mantle. The entire upper surface of the body is covered with more or less conical protuberances that give it a rough, grainy texture.
Where does it live?
It is common on the Atlantic coast and throughout the Mediterranean, from the shallowest waters to a depth of 50 metres, especially in shady, poorly lit places. It prefers to live in small groups where there are sponges, particularly the sponge Petrosia ficiformis, on which it feeds. It can also be found on Haliclona fulva, which it is suspected to feed on.
How does it feed?
It feeds primarily on the sponge Petrosia ficiformis by accumulating petroformins in its digestive glands. These chemicals come from the sponge and, once stored, can be used by the nudibranch as a chemical defence system. In this way a relationship is established between predator and prey.
How does it reproduce?
The reproduction period is between May and August. These animals are hermaphrodites, i.e. they have both sexes, male and female, and carry out cross-fertilisation. The clutches may contain millions of eggs and the resulting larvae first pass through a planktonic phase to finally give rise to young gastropods. The egg clutch forms a white ribbon in form of a spiral.
Is a confusion possible?
Because of their characteristic colouring, st the Mediterranean nor at the Atlantic there are no similar species, therfore it is really to distinguish.
Curiosities
· The scientific name of this species is Peltodoris atromaculata, but previsousy it had also been known as Discodoris atromaculata.
· The specific epithet, ‘atro-’ comes from the Latin ‘ater’ meaning ‘black’, and ‘maculata’ comes from ‘maculatus’ meaning ‘spotted’.
· Its colouring is known as disruptive, as it allows the animal to camouflage itself, so that it blends in with its surroundings.
· Both gills and rhinophores are retractile organs that are sensitive to wave pressure, so that they shorten under any disturbance and only return to their initial length very slowly.
· It has the capacity to lose part of its mantle in situations of danger, although its main defence system is the protection which offer the small spicules located inside its mantle, as well as the camouflage through its colouring.
· Relatively recently it has been proven that the secretions of its coat are not dangerous due to the fact that its pH is neutral.
· It is the mascot of our club, the CIB!
Taxonomy
Phylum: Mollusca, Class: Gastropoda, Subclass: Heterobranchia, Order: Nudibranchia, Suborder: Doridina, Superfamily: Eudoridoidea, Family: Discodorididae, Genus: Peltodoris |
