The brown ridged nudibranch, Dermatobranchus sp. 4, as designated by Gosliner, 1987, 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 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...

 Arminidae

Arminidae

Arminidae is a family of sea slugs, marine gastropod mollusks in the superfamily Arminoidea.- Taxonomy :The Arminidae family is classified within the clade Cladobranchia, itself belonging to the clade Nudibranchia .This family has been renamed several times...

. As at November 2009, it remained undescribed by science.

Distribution

This species has to date only been found off South Africa, on both coasts of the Cape Peninsula, in 10–30 m of water. It appears to be endemic.

Description

The brown ridged nudibranch is a small nudibranch, reaching 25 mm in total length. It is pale-bodied with narrow white ridges running longitudinally down its body. Variable brown blotches run across its body with a distinct brown collar at the head area. Its pale rhinophores are oval with longitudinal ridges.