''Phyllodesmium'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

predatory Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

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 time ...

s, aeolid

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 match, ...

s, marine gastropod molluscs in the family

Facelinidae The Facelinidae are a Taxonomy (biology), taxonomic family (biology), family of colorful sea slugs. These are specifically aeolid nudibranchs. They are marine (ocean), marine gastropod molluscs.Bouchet, P. (2012). Facelinidae. Accessed through: W ...

.Bouchet, P. (2012). ''Phyllodesmium'' Ehrenberg, 1831. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=204424 on 2012-06-05 These nudibranchs occur in the tropical Indo-Pacific Ocean and warm temperate waters of Japan, Tasmania and South Africa. The nudibranchs in this genus often show extraordinary mimicry, each species very closely resembling its prey species, which are

octocorals Octocorallia (also known as Alcyonaria) is a class of Anthozoa comprising around 3,000 species of water-based organisms formed of colonial polyps with 8-fold symmetry. It includes the blue coral, soft corals, sea pens, and gorgonians (sea fan ...

, a kind of

soft coral Alcyonacea, or soft corals, are an order of corals. In addition to the fleshy soft corals, the order Alcyonacea now contains all species previously known as "gorgonian corals", that produce a more or less hard skeleton, though quite different f ...

.Moore E. & Gosliner T. (18 August 2009)
"Three new species of ''Phyllodesmium'' Ehrenberg (Gastropoda: Nudibranchia: Aeolidoidea), and a revised phylogenetic analysis"
''

Zootaxa ''Zootaxa'' is a peer-reviewed scientific mega journal for animal taxonomists. It is published by Magnolia Press (Auckland, New Zealand). The journal was established by Zhi-Qiang Zhang in 2001 and new issues are published multiple times a week ...

'' 2201: 30–48. Some of the species are also unusual in that they are able to utilize

zooxanthellae Zooxanthellae is a colloquial term for single-celled dinoflagellates that are able to live in symbiosis with diverse marine invertebrates including demosponges, corals, jellyfish, and nudibranchs. Most known zooxanthellae are in the genus ''S ...

from their prey, in a symbiotic relationship that provides them with extra nutrition from

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...

, hence they are commonly called "solar-powered" sea slugs (also see the

Sacoglossa Sacoglossa, commonly known as the sacoglossans or the "solar-powered sea slugs", are a superorder of small sea slugs and sea snails, marine gastropod mollusks that belong to the clade Heterobranchia. Sacoglossans live by ingesting the cellular co ...

Species

Species within the genus ''Phyllodesmium'' include: * ''

Phyllodesmium acanthorhinum ''Phyllodesmium acanthorhinum'' is a species of sea slugs, an aeolid nudibranch, a marine gastropod mollusc in the family Facelinidae. In 2015, the International Institute for Species Exploration names it as one of the "Top 10 New Species" for n ...

'' Moore & Gosliner, 2015 * ''

Phyllodesmium briareum ''Phyllodesmium briareum'' is a species of sea slug, an aeolid nudibranch, a marine gastropod mollusc in the family Facelinidae.Bouchet, P. 2015''Phyllodesmium briareum''.In: MolluscaBase (2015). Accessed through: World Register of Marine Spec ...

'' (Bergh, 1896) * '' Phyllodesmium colemani'' Rudman, 1991 * '' Phyllodesmium crypticum'' Rudman, 1981Rudman W. B. (1981). "The anatomy and biology of alcyonarian-feeding aeolid opisthobranch molluscs and their development of symbiosis with zooxanthellae". ''

Zoological Journal of the Linnean Society The ''Zoological Journal of the Linnean Society'' is a monthly peer-reviewed scientific journal covering zoology published by Oxford University Press on behalf of the Linnean Society. The editor-in-chief is Maarten Christenhusz (Linnean Society). ...

'' 72(3): 219-262. . * '' Phyllodesmium guamense'' Avila, Ballesteros, Slattery, Starmer & Paul, 1998 * '' Phyllodesmium horridum'' (Macnae, 1954) * '' Phyllodesmium hyalinum'' (Ehrenberg, 1831) - type species * '' Phyllodesmium iriomotense'' Baba, 1991Baba K. (1991). "Taxonomical study of some species of the genus ''Phyllodesmium'' from Cape Muroto-misaki, Shikoku, and Okinawa Province, Southern Japan (Nudibranchia: Facelinidae)". ''Venus'' 50(2): 109-124
abstract
* '' Phyllodesmium jakobsenae'' Burghardt & Wägele, 2004Burghardt I. & Wägele H. (2004). "A new solar powered species of the genus ''Phyllodesmium'' Ehrenberg, 1831 (Mollusca: Nudibranchia: Aeolidoidea) from Indonesia with analysis of its photosynthetic activity and notes on biology". ''

'' 596: 1-18
PDFt
* '' Phyllodesmium kabiranum'' Baba, 1991 * '' Phyllodesmium karenae'' Moore & Gosliner, 2009 * '' Phyllodesmium koehleri'' Burghardt, Schrödl & Wägele, 2008 * '' Phyllodesmium lembehense'' Burghardt, Schrödl & Wägele, 2008 * '' Phyllodesmium lizardense'' Burghardt, Schrödl & Wägele, 2008Burghardt I., Schrödl M. & Wägele H. (2008). "Three new solar-powered species of the genus ''Phyllodesmium'' Ehrenberg, 1831 (Mollusca: Nudibranchia: Aeolidioidea) from the tropical Indo-Pacific, with analysis of their photosynthetic activity and notes on biology". ''

Journal of Molluscan Studies The ''Journal of Molluscan Studies'' is the peer-reviewed scientific journal of the Malacological Society of London, covering research in malacology.

'' 74(3): 277-292.
abstract
* '' Phyllodesmium longicirrum'' (Bergh, 1905) * '' Phyllodesmium macphersonae'' (Burn, 1962) * '' Phyllodesmium magnum'' Rudman, 1991Rudman W. B. (1991). "Further studies on the taxonomy and biology of the octocoral-feeding genus ''Phyllodesmium'' Ehrenberg, 1831 (Nudibranchia: Aeolidacea)". ''Journal of Molluscan Studies'' 57(2): 167–203
abstract
* '' Phyllodesmium opalescens'' Rudman, 1991 * '' Phyllodesmium orientale'' Baba, 1991 * '' Phyllodesmium parangatum'' Ortiz & Gosliner, 2003 * '' Phyllodesmium pecten'' Rudman, 1981 * '' Phyllodesmium pinnatum'' Moore & Gosliner, 2009 * '' Phyllodesmium poindimiei'' (Risbec, 1928) * ''

Phyllodesmium rudmani ''Phyllodesmium rudmani'' is a species of sea slug, an aeolid nudibranch, a marine (ocean), marine gastropod mollusc in the family Facelinidae. The specific name ''rudmani'' is in honor of malacologist William B. Rudman. Distribution The dist ...

'' Burghardt & Gosliner, 2006Burghardt I. & Gosliner T. M. (2006). "''Phyllodesmium rudmani'' (Mollusca: Nudibranchia: Aeolidoidea), a new solar powered species from the Indo-West Pacific with data on its symbiosis with zooxanthellae". ''

'' 1308: 31-47
abstractfull PDF
* '' Phyllodesmium serratum'' (Baba, 1949) * '' Phyllodesmium tuberculatum'' Moore & Gosliner, 2009 * '' Phyllodesmium undulatum'' Moore & Gosliner, 2014 ;Species brought into synonymy: * ''Phyllodesmium xeniae'' Gohar & Aboul-Ela, 1957: synonym of ''Phyllodesmium hyalinum'' Ehrenberg, 1831 File:Phyllodesmium crypticum.jpg, '' Phyllodesmium crypticum'' File:Phyllodesmium kabiranum.jpg, '' Phyllodesmium kabiranum'' File:Phyllodesmium longicirrum.jpg, '' Phyllodesmium longicirrum''

Ecology

Phyllodesmium briareum and Briareum violacea

Species of the genus ''Phyllodesmium'' are carnivorous and feed on

octocoral Octocorallia (also known as Alcyonaria) is a class of Anthozoa comprising around 3,000 species of water-based organisms formed of colonial polyps with 8-fold symmetry. It includes the blue coral, soft corals, sea pens, and gorgonians (sea fan ...

s (for example in the family

Xeniidae Xeniidae is a family of soft coral in the order Alcyonacea. Predators Predatory sea slugs of the genus '' Phyllodesmium'' are reported to feed on Xeniidae species. Representatives of this family have been observed to provide shelter to juvenil ...

). This is a unique feature within the

Aeolidida The Aeolidida is a taxonomic clade of sea slugs, specifically aeolid nudibranchs, marine gastropod molluscs in the clade Cladobranchia. They are distinguished from other nudibranchs by their possession of cerata containing cnidosacs. Taxo ...

. Some of these nudibranchs contain endo symbiotic

, which are in effect single-celled plants. Zooxanthellae are one kind of dinoflagellate

protist A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the exc ...

s and they live only within other organisms, most notably in corals. The nudibranchs in this genus obtain zooxanthellae from their food, the soft corals. As they previously did within the corals, the zooxanthellae provide the nudibranch with a supply of food in the form of the products of

. The nudibranchs are able to avoid digesting these protists, and sequester them in their tissues instead. This process is somewhat reminiscent of the relationship between the

n sea slugs and the living

chloroplasts A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it in ...

that they are able to sequester. Both these nudibranchs and the sacoglossans have been referred to as "solar-powered sea slugs".Rudman, W.B., 1998 (October 11
Solar-powered sea slugs.
n/nowiki> Sea Slug Forum. Australian Museum, Sydney. Many other species of nudibranchs are brilliantly colored in order to warn away would-be predators, that is, they have

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 o ...

coloring. This is because they contain in their tissues many examples of an organ called the

cnidosac A cnidosac is an anatomical feature that is found in the group of sea slugs known as aeolid nudibranchs, a clade of marine opisthobranch gastropod molluscs. A cnidosac contains cnidocytes, stinging cells that are also known as cnidoblasts or n ...

which contains undischarged

cnidocytes A cnidocyte (also known as a cnidoblast or nematocyte) is an explosive Cell (biology), cell containing one large secretory organelle called a cnidocyst (also known as a cnida () or nematocyst) that can deliver a sting to other organisms. The pre ...

(also known as nematocysts). These are stinging cells that the nudibranchs obtain from the tissues of the

cnidaria Cnidaria () is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in freshwater and marine environments, predominantly the latter. Their distinguishing feature is cnidocytes, specialized cells that ...

ns they eat. Thus the very brightly colored nudibranchs are quite unpalatable for predators. Some nudibranchs, such as ''

Glaucus atlanticus ''Glaucus atlanticus'' (common names include the blue sea dragon, sea swallow, blue angel, blue glaucus, dragon slug, blue dragon, blue sea slug and blue ocean slug) is a species of small, blue sea slug, a pelagic (open-ocean) aeolid nudibran ...

'', are even capable of stinging humans very painfully. The nudibranchs in this genus, however, use an opposite tactic. They do not have cnidosacs, and thus they would in reality be palatable to eat for various predators, however they are almost all extremely well camouflaged, so that they resemble almost perfectly the soft coral on which they live and feed, not only in color but also in form. The shape and form of the cerata of the nudibranch in each individual species resembles very closely the tentacles of the species of soft coral polyp on which that species feeds. This excellent camouflage also makes these nudibranchs difficult for humans to notice, and it is likely that a number of species in this genus have not yet been discovered, described and named scientifically. Another tactic these nudibranchs use to protect themselves is that when threatened by a predator, they can drop one or more of their

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 ...

. These organs will wiggle for some time after being cast off, hopefully distracting a predator away from the animal itself.''Phyllodesmium magnum Rudman, 1991
. Sea Slug Forum, accessed 26 September 2009. This is an example of a defensive technique known as

autotomy Autotomy (from the Greek ''auto-'', "self-" and ''tome'', "severing", αὐτοτομία) or self-amputation, is the behaviour whereby an animal sheds or discards one or more of its own appendages, usually as a self-defense mechanism to elude ...

. A

molecular phylogeny Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

study of ''Phyllodesmium'' by Moore and Gosliner (2011)Moore E. J. & Gosliner T. M. (2011). "Molecular phylogeny and evolution of symbiosis in a clade of Indopacific nudibranchs". ''

Molecular Phylogenetics and Evolution ''Molecular Phylogenetics and Evolution'' is a peer-reviewed scientific journal of evolutionary biology and phylogenetics. The journal is edited by E.A. Zimmer. Indexing The journal is indexed in: * EMBiology *Journal Citation Reports *Scopus ...

'' Volume 58, Issue 1, January 2011, Pages 116–123 . accessed 17 December 2010. demonstrated that the non-symbiotic species of ''Phyllodesmium'' evolved separately from the symbiotic species of ''Phyllodesmium''. However, there is one exception: '' Phyllodesmium karenae'' evolved in the symbiotic clade and subsequently lost its zooxanthellae.

References

External links

* {{Taxonbar, from=Q3901735 Facelinidae Taxa named by Christian Gottfried Ehrenberg