Phyllodesmium is a genus of predatory sea slugs, aeolid nudibranchs, marine gastropod molluscs in the family Facelinidae.[2]
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, a kind of soft coral.[3]
Some of the species are also unusual in that they are able to utilize zooxanthellae from their prey, in a symbiotic relationship that provides them with extra nutrition from photosynthesis, hence they are commonly called "solar-powered" sea slugs (also see the Sacoglossa).[4]
Species within the genus Phyllodesmium include:
Species of the genus Phyllodesmium are carnivorous and feed on octocorals[5] (for example in the family Xeniidae[10]). This is a unique feature within the Aeolidida.[5]
Some of these nudibranchs contain endosymbiotic zooxanthellae, which are in effect single-celled plants.[5] Zooxanthellae are one kind of dinoflagellate protists and they live only within other organisms, most notably in corals. The nudibranchs in this genus obtain zooxanthellae from their food, the soft corals.[6][5] As they previously did within the corals, the zooxanthellae provide the nudibranch with a supply of food in the form of the products of photosynthesis. 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 Sacoglossan sea slugs and the living chloroplasts that they are able to sequester. Both these nudibranchs and the sacoglossans have been referred to as "solar-powered sea slugs".[4][10]
Many other species of nudibranchs are brilliantly colored in order to warn away would-be predators, that is, they have aposematic coloring. This is because they contain in their tissues many examples of an organ called the cnidosac[13] which contains undischarged cnidocytes (also known as nematocysts). These are stinging cells that the nudibranchs obtain from the tissues of the cnidarians they eat. Thus the very brightly colored nudibranchs are quite unpalatable for predators. Some nudibranchs, such as Glaucus atlanticus, 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. These organs will wiggle for some time after being cast off, hopefully distracting a predator away from the animal itself.[14] This is an example of a defensive technique known as autotomy.
A molecular phylogeny study of Phyllodesmium by Moore and Gosliner (2011)[15] demonstrated that the non-symbiotic species of Phyllodesmium evolved separately from the symbiotic species of Phyllodesmium.[15] However, there is one exception: Phyllodesmium karenae evolved in the symbiotic clade and subsequently lost its zooxanthellae.[15]
Phyllodesmium is a genus of predatory sea slugs, aeolid nudibranchs, marine gastropod molluscs in the family Facelinidae.
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, a kind of soft coral.
Some of the species are also unusual in that they are able to utilize zooxanthellae from their prey, in a symbiotic relationship that provides them with extra nutrition from photosynthesis, hence they are commonly called "solar-powered" sea slugs (also see the Sacoglossa).
Phyllodesmium es un género de moluscos nudibranquios de la familia Facelinidae.[1] Estos nudibranquios se localizan en aguas tropicales y templadas de los océanos Índico y Pacífico, alimentándose principalmente de corales blandos. La especie Phyllodesmium rudmani desarrolla unas ceras que imitan los pólipos del coral Heteroxenia, del que se alimenta, pasando así inadvertido frente a posibles predadores, en un ejercicio de cripsis.
El Registro Mundial de Especies Marinas reconoce las siguientes especies válidas en el género Phyllodesmium:[1]
Especies cuyo nombre ha dejado de ser aceptado por sinonimia:
Ceras de Phyllodesmium rudmani imitando pólipos de Heteroxenia
El género se caracteriza por comer corales blandos del orden Alcyonaria; tener la facultad de autotomía en las ceras dorsales, que son ligera o extremamente aplanadas; la disposición de las ceras variable, con arco precardiáco en cada lado, tanto en hilera simple como doble; carecer de glándulas orales, y presentar un par de glándulas salivares tubulares; la abertura genital situada debajo de la extremidad anterior del arco precardiáco derecho; los dientes tienen normalmente cúspides centrales puntiagudas, con un reborde lateral bajo cada lado que tiene muchos dentículos o dientes serrados; el sistema reproductivo cuenta con un solo receptáculo seminal y una próstata formando una masa glandular en la base de los músculos del pene.[2]
La especie de mayor tamaño es Phyllodesmium longicirrum, que alcanza los 14 cm.[3]
Son ovíparos y hermafroditas simultáneos, que cuentan con órganos genitales femeninos y masculinos: receptáculo seminal, bursa copulatrix o vagina, próstata y pene. No obstante, no pueden auto fertilizarse, por lo que necesitan copular con otro individuo para ello. La cópula puede ser unidireccional, entre dos individuos, o en grupo, formando cadenas o círculos en las que un mismo individuo ejerce de macho inseminando a otro ejemplar, mientras simultáneamente es inseminado por otro individuo diferente.[4] Los huevos eclosionan larvas planctónicas velígeras que desarrollan a la forma adulta.
Son predadores carnívoros, alimentándose principalmente de corales blandos, como especies de Briareum, Xenia, Heteroxenia o Pachyclavularia violacea.[5]
Estas pequeñas babosas marinas se distribuyen por los océanos Índico y Pacífico, desde las costas africanas hasta Australia y las islas Marshall, y al norte hasta Japón.[6]
Habitan aguas templadas y tropicales, en un rango de profundidad entre 0 y 30 m.[6]
Se localizan en fondos arenosos y rocosos, y en piscinas intermareales, principalmente de arrecifes de coral.
Phyllodesmium es un género de moluscos nudibranquios de la familia Facelinidae. Estos nudibranquios se localizan en aguas tropicales y templadas de los océanos Índico y Pacífico, alimentándose principalmente de corales blandos. La especie Phyllodesmium rudmani desarrolla unas ceras que imitan los pólipos del coral Heteroxenia, del que se alimenta, pasando así inadvertido frente a posibles predadores, en un ejercicio de cripsis.
Phyllodesmium est un genre de nudibranches carnivores de la famille des Facelinidae.
Ce sont de petits nudibranches éolidiens. Leur corps est allongé, avec un dos recouvert de longs cérates (appendices servant à la respiration, à la digestion et à la défense) et une tête pourvue de rhinophores (appendices sensoriels) et de tentacules buccaux. Leur aspect est souvent mimétique de celui des cnidaires dont ils se nourrissent, notamment les coraux mous de la famille des Xeniidae.
Comme chez le genre Sacoglossa, certaines espèces peuvent aussi utiliser les zooxanthelles de leurs proies pour obtenir un apport nutritif par photosynthèse.
Selon World Register of Marine Species (11 octobre 2014)[1] :
Phyllodesmium est un genre de nudibranches carnivores de la famille des Facelinidae.
Phyllodesmium Ehrenberg, 1831 è un genere di molluschi nudibranchi della famiglia Myrrhinidae.[1]
Comprende le seguenti specie:[1]
Phyllodesmium Ehrenberg, 1831 è un genere di molluschi nudibranchi della famiglia Myrrhinidae.
Phyllodesmium is een geslacht van weekdieren uit de klasse van de Gastropoda (slakken).
Phyllodesmium is een geslacht van weekdieren uit de klasse van de Gastropoda (slakken).
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