The red sponge nudibranch, Rostanga elandsia, 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 dorid 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...

. It is 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

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Discodorididae

Discodorididae

Discodorididae is a taxonomic family of sea slugs, specifically dorid nudibranchs, marine gastropod mollusks in the superfamily Doridoidea. Species in this family belong to the cryptobranch dorid nudibranchs, i.e. they are able to retract their gills into a gill pocket . Most are small and hard to...

.

Distribution

This species has so far only been found around the southern African coast from the Atlantic side of the Cape Peninsula to the eastern side of False Bay. It has been found from the mid-intertidal zone to at least 30 m. It is endemic to South Africa.

Description

The red sponge nudibranch is a yellow-orange to red dorid with scattered small black spots on its notum

Notum

The notum is the dorsal portion of an insect's thoracic segment. It is typically a single large sclerite. It can be further divided into the alinotum which bears the wings and the postnotum which bears the phragma....

. It is extremely well camouflaged on its prey sponges. Its gill

Gill

A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...

s are arranged around the anus and its 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 perfoliate. It may reach a total length of 30 mm.

Ecology

This species feeds on red and yellow-orange sponges which determine the animal's colour. The egg mass is a transparent spiral collar with large orange eggs visible within.