Cuthona speciosa, common name

Common name

A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...

 the "candy nudibranch", is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of sea slug

Slug

Slug is a common name that is normally applied to any gastropod mollusc that lacks a shell, has a very reduced shell, or has a small internal shell...

, an aeolid nudibranch

Nudibranch

A nudibranch is a member of what is now a taxonomic clade, and what was previously a suborder, of soft-bodied, marine gastropod mollusks which shed their shell after their larval stage. They are noted for their often extraordinary colors and striking forms...

, a marine

Marine (ocean)

Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...

 gastropod mollusc in the family Tergipedidae

Tergipedidae

Tergipedidae is a family of seaslugs, aeolid nudibranchs, marine gastropod mollusks in the clade Nudibranchia .- Taxonomy :...

.

Distribution

The candy nudibranch is endemic to South Africa. It is found from the Atlantic coast of the Cape Peninsula

Cape Peninsula

The Cape Peninsula is a generally rocky peninsula that juts out for 75 km into the Atlantic Ocean at the south-western extremity of the African continent. At the southern end of the peninsula are Cape Point and the Cape of Good Hope...

 to Port Elizabeth, intertidally to at least 30 m.

Description

The candy nudibranch is a vividly coloured nudibranch, having a yellow-orange body and turquoise or purple cerata

Cerata

Cerata are anatomical structures found in nudibranch sea slugs, marine opisthobranch gastropod mollusks.They are dorsal and lateral outgrowths on the upper surfaces of the body....

 with yellow tips. The rhinophore

Rhinophore

A rhinophore is one of a pair of club-shaped structures which are the most prominent part of the external head anatomy of a group of sea slugs, marine gastropod opisthobranch mollusks in the order Nudibranchia, the nudibranchs, specifically the dorid nudibranchs.- Etymology :The name relates to the...

s are smooth and usually also yellow-orange, although they make take on the colours of the cerata. The nudibranch grows to 20 mm.

Ecology

The candy nudibranch eats hydroid

Hydroid

-Marine biology:Hydroids are a life stage for most animals of class Hydrozoa, small predators related to jellyfish.-Botany:In mosses, hydroids form the innermost layer of the stem of long, colourless, thin walled cells of small diameter.The cells are dead and lack protoplasm.They function as water...

s of the genus Sertularella. In common with other aeolid nudibranchs, the cerata of the candy nudibranch aid in respiration but also contain extensions of the digestive system. The candy nudibranch eats the hydroid and passes its nematocysts unharmed through its digestive system to the tips of its cerata. Here the nematocysts mature and are then used by the nudibranch for its own defence. It is probable that the bright colours of the candy nudibranch serve to advertise to predators that it is toxic.

Candy nudibranchs are hermaphrodites. Their egg mass is a spiral collar of orange eggs.