Doridacean nudibranchs are characterized by having a more or less dorsoventrally flattened body, by the presence of large mantle that may have embedded spicules and may also have different projections (tubers, papillae) and the existence of a dorsal branchial plume formed by several branchial leaves surrounding the anus. Rhinophores are found in the anterior region of the notum, provided with lamellae and retractile (cryptobranch doridaceans) or just contractile (fanerobranch doridaceans).
Felimare picta by Enric Madrenas
The doridaceans are carnivorous and feed primarily on sponges and bryozoans. They feed by using their radula, that can have some to many teeth on each row, but the species of the family Dendrodorididae lack any radula at all, and feed by sucking food with their suctorial type buccal bulb. Many doridacean species have external parasites of the Copepod Crustaceans group, often of the Splanchnotrophidae family, moving primarily around the gill leaves. Doridaceans have the most powerful defense mechanisms within the nudibranchs. Many species of several families present some mantle glands called MDF (for “Mantle Dermal Formations”) where they accumulate several secondary metabolites that have a large antidepredant effect when they are expelled to the outside, which happens easily when the animal is disturbed. These powerful defensive substances have allowed these nudibranchs to acquire flashy colorations in the course of evolution, called warning (or aposematic) colorations, to prevent attacks by their possible predators.
The updated doridaceans taxonomy is as follows:
- Doridacea infraorder Thiele, 1931
- Superfamily Doridoidea Rafinesque, 1815
- Family Actinocyclidae O’Donoghue, 1929: with genus Actinocyclus Ehrenberg, 1831 and Hallaxa Eliot, 1909, none of which have species in European waters.
- Family Cadlinidae Bergh, 1891: includes species of the genus Aldisa Bergh, 1878 and Cadlina Bergh, 1878, both with representatives in European waters and in the Iberian Peninsula.
- Family Chromodoridae Bergh, 1891: this family includes species from about 17 genus, distributed mainly in tropical and subtropical waters. In Iberian waters there are only species of the genus Felimare (= Hypselodoris until the revision of Johnson & Gosliner 2012) Ev. Marcus & Er. Marcus, 1967 and Felimida (= Chromodoris until that review) Ev. Marcus, 1971.
- Family Discodorididae Bergh, 1891: one of the largest families of nudibranchs, with about 28 different genus, of which Baptodoris Bergh, 1884, Carminodoris Bergh, 1889, Geitodoris Bergh, 1891, Jorunna Bergh, 1876, Paradoris Bergh, 1884, Peltodoris , Bergh, 1880, Platydoris Bergh, 1877, Rostanga, Bergh, 1879, Taringa, Er.Marcus 1955, Tayuva Er. Marcus & Ev. Marcus, 1967 and Thordisa Bergh, 1877, are species that live in European waters.
- Family Dorididae Rafinesque, 1815: contains species of 6 genus, of which only Anisodoris Bergh, 1898 and Doris Linnaeus, 1758 have European species.
- Superfamily Onchidoridoidea Gray, 1827
- Family Akiodoridae Millen & Martynov, 2005: none of the 5 genus including (Akiodoris Bergh, 1879, Armodoris Minichev, 1972, Doridunculus, G.O. Sars, 1878, Echinocorambe Valdés & Bouchet, 1998 and Prodoridunculus Thiele, 1912) has species in Iberian waters.
- Family Goniodorididae H. Adams & A. Adams, 1854, with 8 genus, of which the following are species in European waters: Ancula, Lovén, 1846, Goniodoris Forbes & Goodsir, 1939, Okenia Menke, 1830 and Trapania Pruvot-Fol, 1931.
- Family Onchidorididae Gray, 1827, with 8 genus included in this family, in Iberian waters only have been cited the following: Acanthodoris Gray, 1850, Adalaria Bergh, 1878, Corambe Bergh, 1869, Diaphorodoris Iredale & O’Donoghue, 1923 and Onchidoris Blainville, 1816.
- Superfamily Phyllidioidea Rafinesque, 1814
- Family Dendrodorididae O’Donoghue, 1924 (1864): only two genus in this family whose representatives have no radula, Dendrodoris Ehrenberg, 1831 and Doriopsilla Bergh, 1880, both have species in European waters and Iberian.
- Family Mandellidae Valdes & Gosliner, 1999: includes only one species of the genus Mandelia Valdés & Gosliner, 1999, which is not found in European waters.
- Family Phyllidiidae Rafinesque, 1814, of the 5 genus that conform this family, Ceratophyllidia Eliot, 1903, Phyllidiella Bergh, 1869, Phyllidia Cuvier, 1797, Phyllidiopsis Bergh, 1876, and Reticulida Brunckhorst, 1990, only the last 3 have species living in European waters.
- Superfamily Polyceroidea Alder & Hancock, 1845
- Family Aegiridae P. Fischer, 1883 the monogenic family Aegires Lovén, 1844 has about 24 species, 4 of which live in Iberian waters.
- Family Gymnodorididae Odhner, 1941: includes 4 genus (Gymnodoris Stimpson, 1855, Lamellana Linnaeus, 1992, Lecithophorus Macnae, 1858, Paliolla Burn, 1958), none of them with European species.
- Family Hexabranchidae Bergh, 1891: with a single genus Hexabranchus Ehrenberg, 1828 and only two currently accepted species living in tropical waters. H. sanguineus (Rüppell & Leuckart, 1830) is the famous “Spanish dancer” for his ability to swim by moving their broad mantle edge.
- Family Okadaiidae Baba, 1930: a single genus Vayssierea Risbec, 1928 with 4 species, none of which are found in European waters.
- Family Polyceridae Alder & Hancock, 1845: with a lot of species, includes 5 subfamilies and 19 genus, the following having species in European waters: Limacia OF Müller, 1781, Polycera Cuvier, 1817, Thecacera Fleming, 1828, Plocamopherus Leuckart, 1828, Crimora Alder & Hancock, 1862, Roboastra Bergh, 1877, Polycerella Verrill, 1880, Kaloplocamus Bergh, 1892 and Tambja Burn, 1962.
- Superfamily Doridoidea Rafinesque, 1815
Doridacean species recorded in the Mediterranean or around the Iberian Peninsula: