''Nembrotha cristata'' is a

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 ...

of colourful

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 ...

, a polycerid

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 ...

, 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 ...

mollusk 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 e ...

in the family

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 clade Euct ...

.Bouchet, P. (2015)
''Nembrotha cristata'' Bergh, 1877.
In: MolluscaBase (2015). Accessed through: World Register of Marine Species on 2015-09-06 This species of sea slug is black with green markings; adults are around 50 mm in length, and they live on rock or coral reefs in the tropical

Indo-West Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

Ocean.

Description

''Nembrotha cristata'' is a large black nembrothine ("nembrothid" in much of the literature) that grows to at least 50 mm in length. Its body is covered with raised green nodules. The

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 ...

and

gills 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 are ...

are black, edged in green. Other than the difference in colour, this species is similar in appearance to ''

Nembrotha yonowae ''Nembrotha yonowae'' is a species of colourful sea slug, a dorid nudibranch, a marine gastropod mollusk in the family Polyceridae. It was first described in 1992. Distribution This species is known from the western Indo-Pacific Ocean, includin ...

''.

Distribution

This nudibranch species was described from the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

. It occurs in the tropical

Ocean.Rudman, W.B., 1999 (January 21
''Nembrotha cristata'' Bergh, 1877.
n/nowiki> Sea Slug Forum. Australian Museum, Sydney. It lives at depths between three and twenty metres. These sea slugs live on coral or rock reefs, and have a lifespan of up to a year.

Behaviour

The bright colours of this nudibranch species are an

aposematic Aposematism is the advertising by an animal to potential predators that it is not worth attacking or eating. This unprofitability may consist of any defences which make the prey difficult to kill and eat, such as toxicity, venom, foul taste or ...

warning to predators. These sea slugs eat compound

tunicate A tunicate is a marine invertebrate animal, a member of the subphylum Tunicata (). It is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords (including vertebrates). The subphylum was at one time ca ...

s. Like all

opisthobranch Opisthobranchs () is now an informal name for a large and diverse group of specialized complex gastropods which used to be united in the subclass Opisthobranchia. That taxon is no longer considered to represent a monophyletic grouping. Euopisth ...

s, they are

hermaphrodite In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrate ...

References

External links

*
Photographs at Sea Slugs of the Mediterranean Sea and Elsewhere

Video
- Taken in Bali, Indonesia {{Taxonbar, from=Q3020387 Polyceridae Gastropods described in 1877