Guide to Opisthobranchs Nudibranchia Cladobranchia Proctonotoidea Antiopella cristata

Antiopella cristata

Antiopella cristata (Delle Chiaje, 1841)

Antiopella cristata by Enric Madrenas

Taxonomy

	Superdomain	Biota
	Kingdom	Animalia
	Phylum	Mollusca
	Class	Gastropoda
	Subclass	Heterobranchia
	Infraclass	Euthyneura
	Subterclass	Ringipleura
	Superorder	Nudipleura
	Order	Nudibranchia
	Suborder	Cladobranchia
	Superfamily	Proctonotoidea
	Family	Janolidae
	Genus	Antiopella
	Species	Antiopella cristata (Delle Chiaje, 1841)

	Classification according to Bouchet et al. (2017) Taxonomic source: World Register of Marine Species (AphiaID: 162687).

Synonyms

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 45 m of depth (Đani Iglić, pers.comm.). It ocasionally appears under stones or at shallower depths. 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, Madeira and Azores. In the Iberian Peninsula it has been cited in all coastal areas, both Atlantic and Mediterranean. In Catalonia it is relatively common in many locations of the Costa Brava.

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

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

Similar species
Due to its characteristics, it is unmistakable.

Abundance

Western Mediterranean:
Eastern Mediterranean:
Atlantic Ocean:

Month

This chart displays the monthly observation probability for Antiopella cristata based on our own records.

Vídeo

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

Antiopella cristata by Pascal Girard

More pictures

Bibliography

Steve Long, 2006

Bibliography of Opisthobranchia 1554-2000

Gary McDonald, 2009

Bibliographia Nudibranchia

Further reading

Cite this article as:

Ballesteros, M., Madrenas, E. & Pontes, M. (2022) "Antiopella cristata" in OPK-Opistobranquis. Published: 16/05/2012. Accessed: 25/09/2022. Available at (https://opistobranquis.info/en/uy8Xn)

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Antiopella cristata