''Antiopella capensis'', originally described as ''Janolus capensis'', the Cape silvertip nudibranch, is a beautiful

species In biology, a species is the basic unit of 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 the appropriate s ...

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 matc ...

, or

sea slug Sea slug is a common name for some marine invertebrates with varying levels of resemblance to terrestrial slugs. Most creatures known as sea slugs are gastropods, i.e. they are sea snails (marine gastropod mollusks) that over evolutionary t ...

. 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 The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

in the

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

Proctonotidae Proctonotidae is a family of sea slugs, nudibranchs, marine gastropod molluscs, in the clade Euthyneura Euthyneura is a taxonomic infraclass of snails and slugs, which includes species exclusively from marine, aquatic and terrestrial gastro ...

. Apart from striking differences in the egg ribbons, individuals of this species are externally not distinguishable from the

medallion silvertip nudibranch ''Janolus longidentatus'', the medallion silvertip nudibranch, is a spectacular-looking species of nudibranch, or sea slug. It is a marine gastropod mollusc in the family Proctonotidae. Apart from striking differences in the egg ribbons, individ ...

, ''

Antiopella longidentata '' Antiopella longidentata'' (Gosliner, 1981), previously named ''Janolus longidentatus'', the medallion silvertip nudibranch, is a species of nudibranch, or sea slug. It is a marine gastropod mollusc in the family Proctonotidae. Apart from stri ...

''.

Distribution

This species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the South African coast and is found only from Saldanha Bay to East London, from the intertidal border to at least 40 m.

Description

The Cape silvertip nudibranch grows up to 40 mm in total length. It is a pale-bodied nudibranch with dark- to tan-coloured

cerata :''The tortrix moth genus ''Cerata'' is considered a junior synonym of ''Cydia. Cerata, singular ceras, are anatomical structures found externally in nudibranch sea slugs, especially in aeolid nudibranchs, marine opisthobranch gastropod mollusks ...

with white tips. Its

rhinophores 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 hares ...

are white and rolled. They are separated from one another by an opaque white spherical mass of unknown function known as the rhinophoral crest.

Ecology

This species of nudibranch feeds on moss animals,

bryozoa Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a l ...

ns such as ''

Menipea triseriata ''Menipea'' is a genus of bryozoans belonging to the family Candidae. The genus has almost cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the worl ...

'' and '' Onchoporella buskii''. The egg mass is globular, convoluted and has numerous eggs per capsule.Zsilavecz, G. 2007. ''Nudibranchs of the Cape Peninsula and False Bay''. The egg ribbon of the medallion silvertip is diagnostic for the species: a flat spiral of capsules with only 5-7 eggs per capsule.

References

External links

* http://www.seaslugforum.net/factsheet/janocape {{Taxonbar, from=Q5035206 Proctonotidae Gastropods described in 1907