Spurilla neapolitana

Spurilla neapolitana (delle Chiaje, 1841)

Spurilla neapolitana by Enric Madrenas










































Spurilla neapolitana  (Delle Chiaje, 1841)

 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 138722).

  • Eolis alderiana Deshayes, 1865
  • Eolis conspersa Fischer P., 1869
  • Eolis neapolitana Delle Chiaje, 1841 (original)
  • Flabellina inornata A. Costa, 1866
  • Spurilla mograbina Pruvot-Fol, 1953
  • Spurilla vayssierei Garcia-Gomez & Cervera, 1985

The specimens of this species can reach 70 mm in length, but there is a reported observation of a 150mm specimen (Celia García @ Granada, Spain, pers.com.). The body is coloured pink or light brown pink deppending on specimens, with a somewhat darker dorsum. There are often small white spots on the head, heart area, rhinophores and cerata, giving the body a characteristic mottled appearance. Starting from the heart and towards the tail there is usually an iridescent white line running along the middle dorsal area of the body. Oral tentacles are relatively long and coloured light brown with orange spots. The rhinophores are whitish but they often have the back of the lamellae coloured light brown. The base of the rhinophores has no lamellae, but the upper half has oblique lamellae, some of which are located on the rhinophore dorsal area. The eyes are right behind the base of the rhinophores. The cerata are gathered up in 9 groups on each side of the body. The cerata of each group insert in the body wall forming an arch or saddle. Between the first and second group of cerata there is the cardiac region, where heart contractions, and the separation between the ventricle and atrium, can be observed in live animals. The cerata are long but they have a very characteristic curved shape at the end and are coloured olive green or brown due to the digestive gland that is inside; they can also have whitish spots. The digestive gland extends by dendritic branching around the dorsum, the head region, the oral tentacles and rhinophores of the animal, and is visible by transparency. The larger cerata of each group correspond to the ones located more dorsally, and their size decreases as they are inserted more laterally. The foot is large, coloured light pink, and on the front end it has a pair of short, rounded propodial palps.

This species lives under stones and can be relatively abundant in shallow areas and tidal pools with plenty of loose stones, where it is often found feeding on actiniarians as Anemonia viridis, Aiptasia mutabilis, Bunodactis rubripunctata among other species. The spawn is also laid on the lower face of stones and has the shape of an scalloped narrow cord wound in a spiral of 2-3 turns with a diameter of about 2 cm, and white eggs about 90 microns in size, tightly placed in the cord. Spurilla neapolitana is often parasitized by the endoparasitic copepod crustacean of the genus Splanchnotrophus. During the breeding season of this copepod, females are fertilized by the male body within the nudibranch, and produce a voluminous spawn like a white or pink cord projecting to the outside of the nudibranch body, that can easily be seen between the cerata of the nudibranch. The effects of this parasitism in the nudibranch health are unknown.


  • Spurilla could derive from classic Latin spurium: “marine animal of a similar shape” or spurius: “of ilegitimate birth”, spurious
  • Neapolitana, related to Naples [Napoli] (Italy)

This species is reported in the Eastern Atlantic (Cape Verde, Canary islands, Madeira, Azores) and the European continental shores, both in the Atlantic and the Mediterranean. In the Iberian Peninsula it has been found in all coastal areas, also in the Balearic islands. In Catalonia it is common under stones and in very shallow water in Cubelles and Racó de Salou, and it has been freqüently observed in some localities of the Costa Brava such as Tossa de Mar, Begur and Cadaqués, among others. Originally considered a circumtropical species, Spurilla neapolitana reports from western Atlantic Ocean (Caribbean, Gulf of Mexico) and from the Pacific (Baja California, Costa Rica, Japan) are now assigned to Spurilla braziliana MacFarland, 1909  according to (Carmona et al., 2014) where they demonstrate that these species form a complex of no less than three cryptic species.

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

References for the species: Spurilla neapolitana

Similar species
Aeolidiella alderi. Eyes very apparent on the sides, non-curved cerata, first ring of cerata of a lighter color, as they are not fully occupied by the digestive gland.


    Western Mediterranean:3 out of 5 stars
    Eastern Mediterranean:0 out of 5 stars
    Atlantic Ocean:0 out of 5 stars

This chart displays the monthly observation probability for Spurilla neapolitana based on our own records.



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Further reading

Cite this article as:

Ballesteros, Manuel, Enric Madrenas, Miquel Pontes (2021) "Spurilla neapolitana" in OPK-Opistobranquis. Published: 16/05/2012. Accessed: 26/10/2021. Available at (https://opistobranquis.info/en/DYmzu)

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