Antiopella cristata

Antiopella cristata (Delle Chiaje, 1841)

• Antiopa splendida Alder & Hancock, 1848
• Janolus cristatus (Delle Chiaje, 1841)
• Eolidia cristata Delle Chiaje, 1841
• Eolis cristata Delle Chiaje, 1841 (original)
• Janus spinolae Vérany, 1846

Taxonomic note: A study published by Pola, Hallas and Gosliner (2019) tries to address the uncertainties traditionally presented by the members of the family Proctonotidae, by analyzing four apparently undescribed species of Indo-Pacific Madrellidae and Proctonotidae with the use of detailed morphological and molecular techniques. The results, although they are not completely conclusive because the authors have not been able to analyze samples of all the groups involved, clearly show that Janolidae family must be reinstated, eliminating “de facto” its synonymy with the Proctonotidae family. Within the Janolidae there would be two well-supported clades: one that includes species with smooth ceratas found in the Atlantic and Eastern Pacific oceans, among which is the species Janolus cristatus that, together with other species, would conform the genus Antiopella and, on the other hand, a sister clade that would include other species that traditionally belong to the genus Janolus Bergh, 1884 and Bonisa Gosliner, 1981. A more detailed summary can be read (in Spanish) on VIMAR website.

Description
This nudibranch usually measures 25 mm in length but it has been cited with a maximum length of 80 mm. The body general coloration is translucent light brown, revealing some internal organs and the extensions of the digestive gland. The dorsum is crossed by a longitudinal white line (sometimes with a blu irisation) from the tail to the anterior part of the dorsum, where it splits into two. The side walls of the body may also get spots of the same hue. The rhinophores share the same color of the body and have very oblique lamellae, the apex is whitish. The bases of the rhinophores have no lamellae and join on the back of the head, between them there is a structure called “nuchal caruncle” with a brown and rough surface whose mission seems to be sensorial. The eyes are located at the base of each rhinophore. The most characteristic feature of this species is the existence of numerous papillae or cerata on the back that make it look like an aeolidacean nudibranch. However, these papillae grow from all around the body, including the anterior region of the head, and despite they have ramifications of the digestive gland inside, they lack the cnidosac of the aeolidaceans. The papillae are elongated, bulging somewhat in its central region, and they are translucent, with the apex of bluish-white color. They are contractile and can extend or shrink acquiring a rounded shape, according to the state of the animal. The papillae growing near the foot are much smaller than those located more dorsally. Within each papilla a branch of the digestive gland is visible as a straight brown cord, which ramifies at its apical end. The anus is at the end of a cylindrical, whitish and translucent anal papilla which is located in the back dorsal zone of the body; the top edge of the anal papilla is slightly lobed.

Biology
This species lives on well illuminated rocky walls between 10 and 25 m deep. It sometimes appears under stones. It is usually found in the vicinity or on different species of bryozoans of which it feeds. Several bryozoans have been cited as substrate or food for this species, like Alcyonidium gelatinosum, Bicellariella ciliata, different species of Bugula (B. avicularia, B. flabellata, B. neritina, B. turbinata) and Cellaria sp. The spawn consists of a long and thin string laid in a wavy way; the pink eggs have a size of about 80 microns, several eggs contained in each single ovigerous capsule. When animals are disturbed they are able to autotomize the papillae, which then continue shrinking and stretching after leaving the body, most probably as a defense mechanism. At times, specimens of A. cristata are infested by the ectoparasitic copepod Doridicola agilis.

Etymology

• Antiopella is referred to Antíope (Άντίοπη), according to Greek mythology, a daughter of Aeolus, the Keeper of the Winds.
• Cristata is referred to the crest, according to Bernard PICTON in his book “Nudibranchs of The British Isles”.

Distribution
This species is distributed throughout the European coasts, from the North Sea to the Mediterranean, also in Canary islands and Madeira. In the Iberian Peninsula it has been cited in all coastal areas, both Atlantic and Mediterranean. In Catalonia it is relatively common in some locations of the Northern Costa Brava as Es Caials (Cadaqués).

Known georeferenced records of the species: Antiopella cristata
Sources:
: OBIS : GROC 2010-2011 : Enric Madrenas : João Pedro Silva : Bernard Picton : GBIF.ORG	: OPK : VIMAR : Manuel Ballesteros. : M@re Nostrum : Altres fonts : Marine Regions

References for the species: Antiopella cristata

Cantabria: Hidalgo (1916), Fernández-Ovies (1981, as Antiopella cristata). Galicia: Urgorri and Besteiro (1983, 1984, both records as Antiopella). Portugal: Nobre (1932, as Antiopa cristata), García-Gómez et al. (1991), Calado et al. (1999, 2003). Andalucía (Atl.): Cervera and García (1986). Gibraltar: García-Gómez (1983), García-Gómez et al. (1989). Andalucía (Med.): Luque (1983, 1986, as Antiopella), Templado, Luque and Moreno (1988), Sánchez Tocino, Ocaña and García (2000a), Ocaña et al. (2000). Levante: Fez (1974, as Janus cristatus), Templado, Talavera and Murillo (1987). Catalunya: Theodor (1964), Ballesteros (1980, 1985), Ballesteros (datos no publicados) [Es Caials, Cap Falcó], M@re Nostrum [Es Caials 6/2000]. Canarias: Ortea et al. (2001), Moro et al. (2003), Wirtz and Debelius (2003). Madeira: Wirtz (1995a, 1999).
General: Barletta, 1981:97; Brown & Picton, 1979:18; Eliot, 1906c:373; Farran, 1909:9; Hunnam & Brown, 1975:151; Jutting & Engel, 1936:56; Nordsieck, 1972:71; Pruvot-Fol, 1954b:375; Riedl, 1983:325; Schmekel, 1970:187; Thompson & Brown, 1976:138; Vicente, 1967:156; 1991a:[P] as Antiopella cristata; Bergh, 1873a:598; 1882:65; Costa, 1867:33; Fez Sanchez, 1974:106; Mazzarelli, 1903:286; Misuri, 1917:37; Tchang Si, 1931a:120; Tiberi, 1880:224; Trinchese, 1881:77; 1881a:77; Vayssiere, 1888d:29; 1913a:268 as Janus cristatus; Cattaneo-Vietti, Chemello, & Giannuzzi-Savelli, 1990:155[P]; Dekker, 1989:101; Hayward, Wigham, & Yonow, 1990:720; Marin & Ros, 1990:214; McMillan, 1968:70; Perrone, 1986a:31; Picton & Morrow, 1994:88[P]; Schmekel & Portmann, 1982:177[P]; Swennen, 1987:39; Templado, Talavera, & Murillo, 1987:94; Thompson, 1988:238[P]; Thompson & Brown, 1984:97[P] as Janolus cristatus
Sources: Cervera et al., 2004, Ballesteros, 2007 & 2016, McDonald, 2006 and other sources.

Abundance

Western Mediterranean:
Eastern Mediterranean:
Atlantic Ocean:

Vídeo

Janolus cristatus @ Keratea, Attica, Greece 16m 1-02-2017 by Leonidas Stavrou

More pictures

Antiopella cristata by Enric Madrenas

Antiopella cristata by Enric Madrenas

Antiopella cristata by Enric Madrenas

Antiopella cristata by Enric Madrenas

Antiopella cristata by Enric Madrenas

Antiopella cristata

Antiopella cristata by Enric Madrenas

Antiopella cristata by Bernard Picton

Antiopella cristata @ Mallorca by Lenka Juskaničová

Antiopella cristata @ Astakos Divesite, Ammouliani island, Halkidiki, Greece 29-05-2014 by Yiannis Iliopoulos

Antiopella cristata @ Salpatxot, Illes Medes, Spain 31-03-2012

Antiopella cristata@ Es Caials, Cadaqués, Spain 3-06-2000 by Lluís Aguilar & Albert Ollé

Antiopella cristata @ Es Caials, Cadaqués, Spain 15-05-2010 by Miquel Pontes

Antiopella cristata @ Illa Galera, El Port de la Selva, Spain 9-05-2009 by Miquel Pontes

Antiopella cristata @ Illa Galera, El Port de la Selva, Spain 9-05-2009 by Miquel Pontes

Antiopella cristata @ Netherlands 6-09-2018 by Stefan Verheyen

Bibliography

1246567 Antiopella cristata items 1 entomological-society-of-america author asc 1 https://opistobranquis.info/wp-content/plugins/zotpress/
Bibliography based on the works by Steve Long, 2006. Bibliography of Opisthobranchia 1554-2000 and Gary McDonald, 2009. Bibliographia Nudibranchia, with later updates from other resources.

Further reading

Cite this article as: