Phyllidiidae is a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

sea slug Sea slug is a common name for some Marine biology, marine invertebrates with varying levels of resemblance to terrestrial Slug, slugs. Most creatures known as sea slugs are gastropods, i.e. they are Sea snail, sea snails (marine gastropod moll ...

s, dorid

nudibranch Nudibranchs () are a group of soft-bodied marine gastropod molluscs, belonging to the order Nudibranchia, that shed their shells after their larval stage. They are noted for their often extraordinary colours and striking forms, and they have b ...

s, marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

s in the superfamily

Phyllidioidea Phyllidioidea is a taxonomic superfamily of colorful sea slugs, dorid nudibranchs, marine gastropod mollusks. Taxonomy *Family Phyllidiidae Rafinesque, 1814 *Family Dendrodorididae O'Donoghue, 1924 *Family Mandeliidae Mandela's nudibranch, ...

. This family is within the clade

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

(according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).

Distribution

Most species occur in the tropical

Indo-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 ...

region, but a few species have been found in the tropical Atlantic Ocean and in the

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

Description

The mantle of these oval nudibranchs is flattened dorsoventrally and its dorsal surface is covered with hard, colored

tubercle In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal. In plants A tubercle is generally a wart-like projectio ...

s. This mantle is decorated with contrasting colors and patterns as warning signals to predators. The lamellate

rhinophore A rhinophore is one of a pair of Chemoreceptor, chemosensory club-shaped, rod-shaped or ear-like structures which are the most prominent part of the external head anatomy in sea slugs, Marine (ocean), marine gastropod opisthobranch mollusks suc ...

s can be retracted. Like other dorid nudibranchs, all species have a dorsal

anus In mammals, invertebrates and most fish, the anus (: anuses or ani; from Latin, 'ring' or 'circle') is the external body orifice at the ''exit'' end of the digestive tract (bowel), i.e. the opposite end from the mouth. Its function is to facil ...

, except for the species in the genus ''Fryeria'' where the anus is posteroventral and protrusible. In contrast with the other nudibranchs from the clade

, the species in this family lack buccal armature, i. e.

radula The radula (; : radulae or radulas) is an anatomical structure used by mollusks for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters ...

e and jaws. The gill leaflets are situated along the ventral area and to the side (= ventrolateral ) instead of consisting of a dorsomedian (= along the middle line of the upper surface) circlet . The oral glands, which are closely associated with the

pharynx The pharynx (: pharynges) is the part of the throat behind the human mouth, mouth and nasal cavity, and above the esophagus and trachea (the tubes going down to the stomach and the lungs respectively). It is found in vertebrates and invertebrates ...

and contained in the oral tube, and the stomach have undergone modifications. The female part in the reproductive system of these

hermaphroditic A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic. The individuals of many ...

snails has two separate openings and the male part one. This is called a triaulic reproductive system. It corresponds to the same triaulic condition of the advanced dorids. Most phyllidiids appear in their natural context during day time in a conspicuous way and are thus exposed to their predators. However their colors are warning signals indicating special capabilities to deter predators, such as bioactive chemical defense. This phenomenon is called

aposematism Aposematism is the Advertising in biology, advertising by an animal, whether terrestrial or marine, to potential predation, predators that it is not worth attacking or eating. This unprofitability may consist of any defenses which make the pr ...

. During observations, only one species was found to be always hidden: ''

Phyllidiopsis cardinalis ''Phyllidiopsis cardinalis'' is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusk in the family Phyllidiidae Phyllidiidae is a family (biology), family of sea slugs, dorid nudibranchs, marine (ocean), marine gas ...

'' Bergh.

Feeding habits

There are not many reports on the ecology and the feeding habits of these nudibranchs. As their small mouth lacks a radula and other buccal hard parts, they are known as predators adapted for sucking on sponges. ''

Phyllidia varicosa ''Phyllidia varicosa'' is a species of sea slug, a dorid nudibranch, a shell-less marine (ocean), marine gastropod mollusc in the family Phyllidiidae.Bouchet, P. (2015)''Phyllidia varicosa'' Lamarck, 1801.In: MolluscaBase (2015). Accessed throu ...

'' has been observed feeding on a sponge of the genus '' Hymeniacidon''. ''Phyllidia flava'' has been reported feeding on the sponge ''Acanthella acuta''.

Taxonomy

The original spelling was denoted as family Phyllidia.

Jean-Baptiste Lamarck Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck (1 August 1744 – 18 December 1829), often known simply as Lamarck (; ), was a French naturalist, biologist, academic, and soldier. He was an early proponent of the idea that biologi ...

coined the words "les Phyllidiens" and "les phyllidéens" (1801; 1809). These were later Latinized by J.G. Children (1823) to Phyllidiana, who put them in Hydrobranchiae. The present name Phyllidiidae is now attributed to

Rafinesque Constantine Samuel Rafinesque-Schmaltz (; 22 October 178318 September 1840) was a French early 19th-century polymath born near Constantinople in the Ottoman Empire and self-educated in France. He traveled as a young man in the United States, ult ...

and not to Lamarck. There has been much confusion in the taxonomy of this family, largely caused by inadequate early descriptions and the difficulties of classifying a family where the species all lack radulae. David J. Brunckhorst in his paper "The Systematics and Phylogeny of Phyllidiid Nudibranchs (Doridoidea)" reviewed this family and clarified the status of many species as well as describing new species and a genus.

Phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

analysis through

cladistics Cladistics ( ; from Ancient Greek 'branch') is an approach to Taxonomy (biology), biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesiz ...

shows that the family Phyllidiidae is

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

. The

phylogenetic tree A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA. In ...

shows that ''Ceratophyllidia'' is sister to the rest of the family and ''Phyllidiopsis'' sister to the remaining genera, ''Phyllidiella'' sister to the remaining genera, and ''Reticulidia'' sister to ''Phyllidia '' and ''Fryeria''. This analysis was not entirely supported by a study using the 16S gene. The family contains many undescribed species which are being revealed by DNA analyses.Stoffels B.E., van der Meij S.E., Hoeksema B.W., van Alphen J., van Alen T., Meyers-Muñoz M.A., de Voogd N.J., Tuti Y., van der Velde G., (2016). Phylogenetic relationships within the Phyllidiidae (Opisthobranchia, Nudibranchia). ZooKeys, (605):1-35

Genera

The family Phyllidiidae consists of five genera with a total of more than 80 species. *''

Phyllidia ''Phyllidia'' is a genus of sea slugs, dorid nudibranchs, shell-less marine gastropod molluscs in the family Phyllidiidae.Bouchet, P.; Gofas, S. (2012)''Phyllidia''.Accessed through: World Register of Marine Species on 2012-06-07. Species Speci ...

Cuvier Jean Léopold Nicolas Frédéric, baron Cuvier (23 August 1769 – 13 May 1832), known as Georges Cuvier (; ), was a French natural history, naturalist and zoology, zoologist, sometimes referred to as the "founding father of paleontology". Cuv ...

, 1797 (

type genus In biological taxonomy, the type genus (''genus typica'') is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearin ...

) *'' Ceratophyllidia'' Eliot, 1903 *'' Phyllidiella''

Bergh Bergh is a former municipality in the Dutch province of Gelderland. The municipality included the villages of 's-Heerenberg, Zeddam, and Stokkum. In 2005, it merged with Didam to form the new municipality of Montferland Montferland () i ...

, 1869 *'' Phyllidiopsis''

, 1875 *'' Reticulidia'' Brunckhorst, 1990 ;Genera brought into synonymy: *'' Fryeria'' Gray, 1853 : synonym of ''Phyllidia'' Cuvier, 1797 * ''Reyfria'' Yonow, 1986: synonym of ''Phyllidia'' Cuvier, 1797

References

{{Authority control Taxa named by Constantine Samuel Rafinesque