Aldisa smaragdina

Aldisa smaragdina (Ortea, Perez & Llera, 1982)

Aldisa smaragdina by Luis Ángel Díaz Álvarez

Class: Gastropoda Cuvier, 1797
Subclass: Heterobranchia J.E. Gray, 1840
Clade: Euthyneura Spengel, 1881
Clade: Nudipleura Wägele & Willan, 2000
Order: Nudibranchia Cuvier, 1817
Suborder: Euctenidiacea Tardy, 1970
Infraorder: Doridacea Thiele, 1931
Superfamily: Doridoidea Rafinesque, 1815
Family: Cadlinidae Bergh, 1891
Genus: Aldisa Bergh, 1878
Species: Aldisa smaragdina Ortea, Perez & Llera, 1982

Taxonomic note: In the last revision of the genus (Millen & Gosliner, 1985) the authors indicate that the situation is unclear. Aldisa smaragdina is believed to be a synonymous with the former Aldisa binotata Pruvot-Fol, 1953. The problem is that the original description of A. binotata is poor, with no information of its anatomy. The unique specimen on which the description was based is lost, so it can not be studied. So European researchers use the name Aldisa smaragdina, as there is no consensus on whether Aldisa binotata can be recognized.

The body is dorso-ventrally flattened, up to 30 mm of length and deep red colored. The mantle is covered with small tubercles. There are two large dark oval spots located between the rhinophores and the gill. There is also a quite faded whitish band on each side, located right behind the first dorsal spot. It has two lamellated rhinophores, with few lamellae arranged almost vertically, protected by tuberculated rhinophoral sheaths. The gill consists of 5 reddish, white tipped gill leaves, protected by a crenulated sheath (with a series of crested mantle projections). The oral tentacles are short and blunt, slightly rolled.

It can be confused with Aldisa banyulensis Pruvot-Fol, 1951, that despite it is also red with two dark spots on the back, it is smaller (with a maximum of 15 mm), has the white dorsal band located right before the second dorsal spot, it has 8 completely translucent red (without white tips) gill leaves, rhinophores with more numerous lamellae that are horizontally arranged, the rhinophoric sheaths and gill sheath with smooth edges, with flattened and triangular, pointy, oral tentacles, it feeds on another sponge: Hemymicale columella, and put less eggs that are larger (200μm in diameter). There is another species with which could be confused, Aldisa expleta Ortea, Perez & Llera, 1982, but it lacks the dark dorsal spots.

Lives on rocky bottoms, from 3 m depth, where it feeds sponge Phorbas fictitius (Bowerbank, 1866) and is usually found on it, as it has the same coloration as the sponge and the dark spots on the dorsum mimic the inhalent openings, called pore-sieves (cribri), of the sponge, in what is known as crypsis by homocromy. For this reason it is a difficult to see species, and is considered rare. The spawn is a single turn of 1 cm diameter with capsules containing relatively small red eggs (130μm in diameter) each. Skin produces certain substances similar to progesterone.


  • Aldisa. Probably referred to an Iceland viking saga of the same name.
  • Smaragdina. From Greek “smaragdos”, meaning “emerald”, because of the colour of the gills, often greenish white.

This species was described in 1982 with specimens collected in the waters of the Canary Islands and Asturias. Later it has been cited in the waters of Galicia, Portugal, including Azores and Madeira, also in Morocco and Cape Verde, as well as in the Mediterranean, Gibraltar and the Andalusian coast, also in Levantine coast of Spain and the Balearic Islands. Not present yet in Catalonia (GROC reports for Catalonia correspond to Aldisa banyulensis).

Known georeferenced records of the species: Aldisa smaragdina
: GROC 2010-2011
: Enric Madrenas
: João Pedro Silva
: Bernard Picton
: Manuel Ballesteros.
: M@re Nostrum
: Altres fonts
: Marine Regions

References for the species: Aldisa smaragdina

    Galicia: Ortea (1978a, as A. banyulensis). Portugal: García-Gómez et al. (1991), Calado et al. (1999, as A. binotata), Calado et al. (2003). Gibraltar: García-Gómez (1983), García-Gómez et al. (1989). Andalucía (Med.): Luque (1983, 1986), Templado et al. (1993b), Ocaña et al. (2000), Gavagnin et al. (2002). Levante: Templado, Talavera and Murillo (1983), Ballesteros et al. (1986), Gavagnin et al. (2002). Baleares: Ballesteros and Templado (1996). Canarias: Ortea, Pérez Sánchez and Llera (1982), Pérez-Sánchez and Moreno (1990), Pérez Sánchez, Bacallado and Ortea (1991), Malaquias and Calado (1997), Ortea et al. (2001, 2003), Moro et al. (2003), Wirtz and Debelius (2003). Madeira: Wirtz (1999), Malaquias et al. (2001). Azores: Wirtz (1998), Ávila et al. (1998), Ávila (2000, as A. binotata), Malaquias (2001), Wirtz and Debelius (2003).

    General: Ballesteros, Barrajon, Luque, Moreno, Talavera, & Templado, 1986:49; Luque, 1983:66

    Sources: Cervera et al., 2004, Ballesteros, 2007 & 2016, McDonald, 2006 and other sources.


    Western Mediterranean:
    Eastern Mediterranean:
    Atlantic Ocean:
This chart displays the observation probability for Aldisa smaragdina based on our own records.

More pictures


Further reading

Cite this article as:

Pontes, Miquel, Manuel Ballesteros, Enric Madrenas (2012-2018) "Aldisa smaragdina" in OPK-Opistobranquis, Published: 16/05/2012, Accessed: 19/01/2018 at (

In order to copy this cite or text fragments you must be a registered user.