The aeolidaceans differ from other nudibranchs by their sleek body and the presence of groups of papillae, called cerata, on the back and sides of the body. Aeolidaceans are usually colorful, specially on the dorsal papillae. The head has, on the front, the oral tentacles, long and thin, and the rhinophores on the top, which can be smooth or have lamellae or warts.

Dondice banyulensis by Enric Madrenas

The digestive gland is highly branched and its branches, in the form of hollow conduit, enter inside of each cerata. In many species, the end of the digestive gland on each cerata expands, forming a spherical small bag called cnidosac that is communicated with the outside through a pore, the cnidopore, located on the tip of the cerata. They breath through the skin (cutaneous respiration) because they lack gills, so they use the cerata for gas exchange. Radula is narrow, with a row of teeth (monoseriate radula) or 3 teeth in each row (triseriate radula); generally a pair of chitinous jaws are found in the anterior part of the buccal bulb. Genital and anal orifices are located to the right of the body. The foot may differentiate, in its anterior zone, a pair of propodial palps, shaped short and triangular. Aeolidaceans prey mainly on Cnidarians: polyps of hydrozoans, jellyfish and anemones. This specialization provides these nudibranchs food as well as a defense mechanism of great biological interest because they are able to use for self-defense the stinging capsules (or cnidocysts) from their prey. For still unknown reasons, these cnidocysts are not triggered nor digested by the digestive juices of nudibranch, so they pass through the ramifications of the digestive gland until they reach the cnidosacs on the tip of the cerata, where they are stored. These cnidocysts can be expelled to the outside by contact with the potential predator, they are triggered and perform their defensive action. Some species have specialized in feeding on fish eggs, cirriped crustaceans or even other species of nudibranchs. The aeolidaceans are usually found on hydroid colonies, often the same species that serves them as food, and tend to lay their spawn there as well, usually in the form of a ribbon wrapped in various ways. At other times they can be found below stones, near anemones, even at very shallow depths, or can be found wandering on the rock walls abundant with algae and invertebrates.


The updated taxonomy of Aeolidaceans is as follows

  • Parvorder Aeolidida
    • Superfamily Aeolidioidea Gray, 1827
      • Family Aeolidiidae Gray, 1827: includes about 10 genus currently accepted, among them, the following have species in European waters: Aeolidia Cuvier, 1797, Aeolidiella Bergh, 1867, Berghia Trinchese, 1877, Cerberilla Bergh, 1873, Limenandra Haefelfinger & Stamm, Spurilla 1968 Bergh, 1864.
      • Family Facelinidae Berg, 1889: a large family that includes six species subfamilies and 33 genus distributed worldwide, of which the following have species in European waters: Algarvia Garcia-Gomez & Cervera, 1990, Antonietta Schmekel, 1966 Calorie Trinchese, 1888, Cratena Bergh, 1864, Facelina, Aler & Hancock, 1855, Facelinopsis Pruvt-Fol, 1954, Dicata Schmekel, 1967, Dondice Marcus, 1958, Favorinus M.E. Gray, 1850, Pruvotfolia Tardy, 1969, Rolandia Pruvot-Fol, 1951.
      • Family Glaucidae Gray, 1827: monogeneric family with a single genys Glaucus Forster, 1777 and two pelagic nudibranch species, geographically spread, that live floating below the surface film of water and prey on jellyfish. Glaucus atlanticus Forster, 1777 is cosmopolitan and has been quoted in the waters of the Iberian Peninsula.
      • Family Piseinotecidae Edmunds, 1970: family with a single genus Piseinotecus Er. Marcus, 1955 and only 4 species, of which 3 are found European and Iberian waters.
      • Family Pleurolidiidae Bern, 1966: only one genus Protaeolidia Baba, 1955 with a single Pacific species P. atra Baba, 1955.
      • Family Unidentidae Millen & Hermosillo, 2012: a very recently described family with a single genus so far Unidentia Millen & Hermosillo, 2012, with a single species living in the Mexican Pacific coast.
    • Superfamily Fionoidea Gray, 1857
      • Family Calmidae Iredale & O’Donoghue, 1923: a single genus Calma Alder & Hancock, 1855 and two species, C. glaucoides (Alder & Hancock, 1854) and C. gobioophaga Calado & Urgorri , 2002, both living on the coasts of the Iberian Peninsula and specialized on preying litoral fish eggs.
      • Family Eubranchidae Odhner, 1934: from the 8 accepted genus only one Eubranchus Forbes, 1838 is found in Iberian waters.
      • Family Fionidae Gray, 1857: This family has a single genus Fiona Alder & Hancock [in Forbes & Hanley], 1853 with a single species Fiona pinnata (Eschscholtz, 1831) which has a characteristic pelagic life, living on drifting floating objects and feeding on cirriped crustaceans of the genus Lepas.
      • Family Pseudovermidae Thiele, 1931: monogeneric family with a single genus Pseudovermis Périaslavzeff , 1891 and 16 known species with only one P. artabrensis Urgorri, Cobo & Besteiro, 1991 living in Iberian waters. All species of this family are of very small size and have their body modified to live in the marine interstitial environment.
      • Tergipedidae Family Bergh, 1889: of the 8 genus of this family, only the following have representatives in European and Iberian waters: Catriona Wickworth, 1941, Cuthona Alder & Hancock, 1855, Tenellia A. Costa, 1866 and Tergipes Cuvier, 1805.
    • Superfamily Flabellinoidea Bergh, 1889
      • Flabellinidae Family Bergh, 1889: from the 7 genus currently accepted, only three are found in European waters: Flabellina Gray, 1833, Calmella Eliot, 1910 and Cumanotus Odhner, 1906.
      • Family Notaeolidiidae Eliot, 1910: a single genus Notaeolidia Eliot, 1905 with three species living in Antarctic waters: N. depressa Eliot, 1907, N. gigas Eliot, 1905 and N. schmekelae Wägele, 1990.

Aeolidacean species recorded in the Mediterranean Sea or around the Iberian Peninsula:

Aeolidia papillosa by Manuel Ballesteros

Aeolidia papillosa

Aeolidia filomenae @ Baleal, Portugal 15-08-2014 by João Pedro Silva

Aeolidia filomenae

Aeolidiella alderi by Enric Madrenas

Aeolidiella alderi

Aeolidiella glauca by Klas Malmberg (Sweden)

Aeolidiella glauca

Aeolidiella sanguinea (Atl.E)

Aeolidiella sanguinea

Anteaeolidiella indica by José Carlos García Gómez

Anteaeolidiella indica

Antaeolidiella lurana @ Laguna Maremorto, Bacoli, Napoli (July 2013) by Guido Villani

Anteaeolidiella lurana

Babakina anadoni @ Isla de Tarifa (Med) 06-2015 by Manuel Martínez Chacón

Babakina anadoni

Baenopsis baetica @ Tarifa (Spain) by Manuel Martínez Chacón

Baenopsis baetica

Baeolidia moebii @ Negros Oriental, Philippines 26-10-2003 by Erwin Köhler

Baeolidia moebii

Berghia coerulescens by Enric Madrenas

Berghia coerulescens

Berghia columbina @ Mataró by Manuel Ballesteros

Berghia columbina

Berghia verrucicornis by José Carlos García Gómez

Berghia verrucicornis

Calma glaucoides by Enric Madrenas

Calma glaucoides

Calma gobioophaga by Enric madrenas

Calma gobioophaga

Calmella cavolini by Enric Madrenas

Calmella cavolini

Calmella gaditana by José Carlos García Gómez

Calmella gaditana

Caloria elegans by Enric Madrenas

Caloria elegans

Caloria indica by Yury Ivanov (

Caloria indica

Carronella pellucida by Klas Malmberg (Sweden)

Carronella pellucida

Catriona aurantia by Klas Malmberg (Sweden)

Catriona aurantia

Catriona maua @ Lake Worth Lagoon, Florida 23-09-2016 by Ariane Dimitris

Catriona maua

Cerberilla bernadettae @ Sepieres (L'Escala) 4-08-2016 by Enric Madrenas

Cerberilla bernadettae

Coryphella verrucosa @ Norway by Viktor Vasskog Grøtan

Coryphella verrucosa

Coryphellina rubrolineata (Beirut, Lebanon) by Sonja Ooms

Coryphellina rubrolineata

Cratena peregrina

Cratena peregrina

Cumanotus beaumonti by Gilles Cavignaux

Cumanotus beaumonti

Cuthona nana - Photograph ©Bernard Picton

Cuthona nana

Cuthona perca @ Palo Alto, California, USA by Gary McDonald

Cuthona perca

Dicata odhneri by Cataldo Licchelli

Dicata odhneri

Dondice banyulensis by Enric Madrenas

Dondice banyulensis

Dondice occidentalis @ Key Largo, Florida (USA) by Manuel Malaquías

Dondice occidentalis

Edmundsella pedata by Enric Madrenas

Edmundsella pedata

Eubranchus amazighi by Naoufal Tamsouri

Eubranchus amazighi

Eubranchus capellinii @ Genova, Italy by Salvatore Trinchese (1877-1879)

Eubranchus capellinii

Eubranchus cingulatus by José Carlos García Gómez

Eubranchus cingulatus

Eubranchus doriae

Eubranchus doriae

Eubranchus exiguus

Eubranchus exiguus

Eubranchus farrani (forma A) by Enric Madrenas

Eubranchus farrani

Eubranchus linensis by Carlos Fernandez Cid

Eubranchus linensis

Eubranchus pallidus Salcombe, Devon, England. 18 May 1975

Eubranchus pallidus

Eubranchus prietoi by José Carlos García Gómez

Eubranchus prietoi

Eubranchus tricolor @ Norway by Viktor Vasskog Grøtan

Eubranchus tricolor

Eubranchus vittatus by Klas Malmberg (Sweden)

Eubranchus vittatus

Facelina annulicornis @ Costa Brava (Spain) by Enric Madrenas

Facelina annulicornis

Facelina auriculata @ Aiguafreda (Begur), 10-04-2010 by Miquel Pontes

Facelina auriculata

Facelina bostoniensis - Photograph ©Bernard Picton

Facelina bostoniensis

Facelina dubia - Photograph ©Bernard Picton

Facelina dubia

Facelina fusca @ Portlligat (Cadaqués) 20080531 by Miquel Pontes

Facelina fusca

Facelina quatrefagesi by Joao Pedro Silva

Facelina quatrefagesi

Facelina rubrovittata by Enric Madrenas

Facelina rubrovittata

Facelina schwobi by Manuel Ballesteros

Facelina schwobi

Facelinopsis marioni by Enric Madrenas

Facelinopsis marioni

Favorinus blianus moullieres 21062008 by Jean Michel Crouzet

Favorinus blianus

Favorinus branchialis by Enric Madrenas

Favorinus branchialis

Favorinus ghanensis

Favorinus ghanensis

Favorinus vitreus by Manuel Ballesteros

Favorinus vitreus

Fiona pinnata (Portugal) by Joao Pedro Silva

Fiona pinnata

Fjordia chriskaugei @ Norway by Viktor Vasskog Grøtan

Fjordia chriskaugei

Fjordia insolita by José Carlos García Gómez

Fjordia insolita

Fjordia lineata by Enric Madrenas

Fjordia lineata

Flabellina affinis by Enric Madrenas

Flabellina affinis

Flabellina dushia @ Lake Worth lagoon, West Palm Beach, Florida, USA 8-07-2007 by Anne DuPont

Flabellina dushia

Glaucus atlanticus @ Ilha do Príncipe (São Tomé e Príncipe) 23-09-2016 by Aketza Herrero

Glaucus atlanticus

Godiva quadricolor @ Laguna Maremorto, Bacoli, Napoli (July 2013) by Guido Villani

Godiva quadricolor

Learchis poica @ Lake Worth Lagoon, Florida, USA by Sandra Edwards

Learchis poica

Limenandra nodosa

Limenandra nodosa

Luisella babai by Enric Madrenas

Luisella babai

Microchlamylla gracilis with spawn @ Netherlands 27-03-2017 by Stefan Verheyen

Microchlamylla gracilis

Paraflabellina gabinierei by Enric Madrenas

Paraflabellina gabinierei

Paraflabellina ischitana by Enric Madrenas

Paraflabellina ischitana

Phidiana lynceus @ Lake Worth Lagoon, Florida 3-06-2012 by Anne Dupont

Phidiana lynceus

Phidiana militaris @ Hoi Ha Wan Marine Park, Hong Kong (6m) 20°C, 17-04-2016 by Markus Rummel

Phidiana militaris

Piseinotecus soussi by Jordi Regàs

Piseinotecus soussi

Piseinotecus sphaeriferus @Azoia, Setúbal, Portugal 27-08-2011 by João Pedro Silva

Piseinotecus sphaeriferus

Pruvotfolia pselliotes @ Split (Croatia) 0.5m by Jakov Prkić

Pruvotfolia pselliotes

Rubramoena amoena 6 mm @ Lephinchapel, Loch Fyne, Scotland 15m 5-10-2008 by Jim Anderson

Rubramoena amoena

Spurilla neapolitana by Enric Madrenas

Spurilla neapolitana

Tenellia adspersa by Klas Malmberg

Tenellia adspersa

Tergipes tergipes - Photograph ©Bernard Picton

Tergipes tergipes

Trinchesia albopunctata by Manuel Ballesteros

Trinchesia albopunctata

Trinchesia caerulea @ Strangford Lough, Co Down, Ireland by Bernard Picton

Trinchesia caerulea

Trinchesia foliata Murles Point, Co. Donegal, Ireland - Bernard Picton

Trinchesia foliata

Trinchesia genovae by Enric Madrenas

Trinchesia genovae

Trinchesia granosa @ Banyuls sur Mer 1-07-1991 (source Wikipedia CC-BY) by Géry Parent

Trinchesia granosa

Trinchesia miniostriata by Miquel Pontes

Trinchesia miniostriata

Trinchesia ocellata by Enric Madrenas

Trinchesia ocellata