The crowned nudibranch (''Polycera capensis'') is a

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

dorid ''Doridacea'' is a taxonomic grouping of dorid nudibranchs, shell-less marine gastropod mollusks.Bouchet P. & Rocroi J.-P. (Ed.); Frýda J., Hausdorf B., Ponder W., Valdes A. & Warén A. 2005''Classification and nomenclator of gastropod families ...

nudibranch Nudibranchs () are a group of soft-bodied marine gastropod molluscs which shed their shells after their larval stage. They are noted for their often extraordinary colours and striking forms, and they have been given colourful nicknames to mat ...

. It is a

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

gastropod mollusc in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Polyceridae The Polyceridae are a taxonomic family of sea slugs, dorid nudibranchs, marine gastropod mollusks within the superfamily Polyceroidea. Taxonomy The family Polyceridae is classified within the clade Doridacea, itself belonging to the clad ...

Distribution

This species is found off the

southern African Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a numbe ...

coast from Luderitz in Namibia to Port Alfred in South Africa. It is found from the intertidal to 35 m. It has been reported from Australia.

Description

The crowned nudibranch is a smooth-bodied variably coloured nudibranch. The ground colour is white or grey and there are usually black, yellow or orange stripes longitudinally along the

notum The notum (plural nota) is the dorsal portion of an insect's thoracic segment, or the dorsal surface of the body of nudibranch gastropods. The word "notum" is always applied to dorsal structures; in other words structures that are part of the back ...

, though these can be absent. The head has six yellow projections. The

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they ar ...

s and

rhinophore A rhinophore is one of a pair of chemosensory club-shaped, rod-shaped or ear-like structures which are the most prominent part of the external head anatomy in sea slugs, marine gastropod opisthobranch mollusks such as the nudibranchs, sea ...

s are black, and may be spotted with yellow. Alongside the gills is a pair of yellow projections. The animal may reach 50 mm in total length. A study using DNA sequencing found that there were two species amongst specimens identified as ''P. capensis'', one of which appears to be the

Twin-crowned nudibranch The twin-crowned nudibranch, scientific name ''Polycera'' sp., as designated by Gosliner, 1987, is a species of dorid nudibranch. It is a marine gastropod mollusc in the family Polyceridae. As of November 2009, it was undescribed by science ...

of Gosliner, 1987.Palomar, G.; Pola, M.; Garcia-Vazquez, E. (2013). First molecular phylogeny of the subfamily Polycerinae (Mollusca, Nudibranchia, Polyceridae). Helgoland Marine Research. 68(1): 143-153.

Ecology

The crowned nudibranch feeds on bryozoans of the genus ''

Bugula ''Bugula'' is a genus of common colonial arborescent bryozoa, often mistaken for seaweed. It commonly grows upright in bushy colonies of up to 15 cm in height.Bock, P. (2015). Bugula Oken, 1815. In: Bock, P.; Gordon, D. (2015) World List of ...

''. Its egg ribbon is a wavy white collar.

References

{{Taxonbar, from=Q5189554 Polyceridae Gastropods described in 1824