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

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: ★★★☆☆
    Eastern Mediterranean: ★☆☆☆☆
    Atlantic Ocean: ★★☆☆☆

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



More pictures


    Abbott RT. 1974. American seashells. The marine mollusca of the Atlantic and Pacific coast of North America. Van Nostrand, New York. 663 pp., 24 pls. [October 1974].
    Aguado Jiménez F, Marín A. 2007. Warning coloration associated with nematocyst-based defences in aeolidiodean nudibranchs. Journal of Molluscan Studies 73(1):23-28.
    Altimira C, Ros J. 1979. Algunos moluscos marinos de las Islas Canarias. Vieraea 8 (1): 3-12.
    Amor MJ, Ribes E. 1994. Aspectos ultraestructurales de la ovotestis de Dendrodoris grandiflora (Mollusca, Nudibranchia). X Congreso Nacional de Malacologia, Barcelona 13 al 16 de Septiembre de 1994, Libro de Resumenes; pp 73-74.
    Angulo-Campillo O. 2005. A four year survey of the opisthobranch fauna (Gastropoda,  Opisthobranchia) from Baja California Sur, Mexico. Vita Malacologica 3:43-50.
    Arias JL, López Iglesias C, Menendez Pelaez A, et al. 1985. Datos morfometricos para el establecimiento de areas en el ganglio cerebroide de Spurilla neapolitana (Opistobranquio). Morphometric data to establish areas in the cerebroid ganglia of Spurilla neapolitana (Opisthobranchia). Iberus 5:31-36.
    Arias JL, Menendez Pelaez M, López Iglesias C, et al. 1985. Condiciones optimas para la preservacion ultraestructural de los moluscos opistobranquios. Optimal conditions for the ultrastructural preservation of opisthobranchia molluscs. Iberus 5:37-42.
    Bacallado JJ, Ortea J, Moro L, et al. 2008. Inventario de los moluscos de la marina de Arrecife, Lanzarote. Canarias Conservación.:1–32. Available from https://www.canariasconservacion.org/LA%20MARINA/DOC-16-Inventario%20de%20los%20moluscos%20de%20la%20marina%20de%20arrecife%202008.pdf.
    Ballesteros M. 1977. Sobre Spurilla neapolitana Delle chiaje (1824) y Berghia verrucicornis A. Costa (1864), dos Aeolidacea (Gastropoda: Opisthobranchia) recolectados en Cubellas (Barcelona). P. Dept. Zool., II:7-12.
    Ballesteros M. 1978. Contribución al conocimiento de la fauna bentónica de Cubellas. Publicaciones del Departamento de Zoología (Barcelona) 3: 11-23.
    Ballesteros M. 1984. Adiciones a la fauna de opistobranquios de Cubellas (Tarragona). Miscelánea Zoológica 8: 41-49.
    Ballesteros M. 1984. Nudibranquios: miscelanea de formas y coloraciones. Immersio 3(4):20-24.
    Ballesteros M. 1991. Els Opistobranquis. pp. 416-427. In: Historia Natural dels Països Catalans,  Invertebrats no artròpodes. Enciclopèdia Catalana. Barcelona.
    Ballesteros M. 2007. Lista actualizada de los opistobranquios (Mollusca: Gastropoda: Opisthobranchia) de las costas catalanas. Spira. 2(3):163–188.
    Ballesteros M. 1980. Contribución al conocimientos de los Sacoglosos y Nudibranquios (Mollusca: Opisthobranchia). Estudio anatómico, sistemático y faunístico de las especies del mediterráneo español. Tesis Doctoral. Barcelona: Universitat de Barcelona.
    Ballesteros M, Barrajón A, Luque A, et al. 1986. Contribución al conocimiento de los Moluscos Gasterópodos marinos de Almería. Iberus, 6: 39-57.
    Ballesteros M, Álvarez C, Mateo B. 1986. Aproximación a la fauna de opistobranquios de la isla de Menorca. Publicaciones del Departamento de Zoología (Barcelona) 12: 93-106.
    Ballesteros M, Pontes M, Madrenas E. 2015. Opisthobranch from Medes Islands (Marine Protected Area, Costa Brava, Catalonia, NE Spain): 40 years of study. Available from https://www.facebook.com/people/5th-International-Workshop-on-Opisthobranchs/100072425991990/.
    Ballesteros M, Madrenas E, Pontes M. 2016. Actualización del catálogo de los moluscos opistobranquios (Gastropoda: Heterobranchia) de las costas catalanas. Spira. 6:1–28.
    Ballesteros M, Pontes M, Madrenas E. 2019. Els nudibranquis del mar català. Figueres: Brau Edicions. 192 p.
    Ballesteros M, Madrenas E, Pontes M. 2024. OPK - Opistobranquis. Available from https://opistobranquis.info/.
    Bandel K. 1976. Egg masses of 27 Caribbean opisthobranchs from Santa Marta, Columbia. Studies on the Neotropical Fauna & Environment 11(1-2):87-118.
    Barash A, Danin Z. 1992. Annotated list of Mediterranean molluscs of Israel and Sinai, viii. Fauna Palaestina, Mollusca I. Israel Academy of Sciences &  Humanities.
    Barash A, Danin Z. 1971. Opisthobranchia (Mollusca) from the Mediterranean waters of Israel. Israel Journal of Zoology, 20, 151-200.
    Barash A, Danin Z. 1982. Mediterranean Mollusca of Israel and Sinai: composition and distribution. Israel Journal of Zoology, 31, 86-118.
    Barash A, Zenziper Z. 1984. On the food of some opisthobranchs found in the Mediterranean waters of Israel. Levantina (Israel Malacological Society) 51:585-598.
    Barletta G. 1981. Gasteropodi nudi (Pleurobranchomorpha, Sacoglossa, Aplysiomorpha e Nudibranchia) Consiglio Nazionale delle Richerche, Guide per il riconoscimento delle specie animali delle acque lagunari e costiere italiane AQ/1/92, 3. Quaderni della Civica Stazione Idrobiologica di Milano (9):1-124.
    Barletta G, Melone G. 1976. Nudibranchi del Promontorio di Portofino (Genova) (Gastropoda Nudibranchia). Natura, Societa Italiana di Scienze Naturali, Milano 67(3-4):203-236.
    Barletta G, Mariani M, Perego C. 1990. Considerazioni preliminari sugli opistobranchi viventi nella baia di Paraggi (Ge). Lavori della Societa Italiana di Malacologia 23:247-260.
    Bebbington A, Thompson TE. 1968. Note sur les opisthobranches du Bassin d’Arcachon. Actes de la Societe Linneenne de Bordeaux, ser. A, 105(5):1-35.
    Bedot M. 1896. Note sur les cellules urticantes. Revue Suisse de Zoologie 3(4):533-539, pl 18.
    Bedulli D, Cattaneo-Vietti R, Chemello R, et al. 1995. Gastropoda Opisthobranchia, Divasibranchia, Gymnomorpha, Fascicolo 15, pp. 1-23.  In: A. Minelli, A. Ruffo, & S. La Posta (Eds.). Checklist delle specie fauna italiana. Bologna: Calderini (Checklist delle specie della Fauna Italiana).
    Behrens DW, Hermosillo A. 2005. Eastern Pacific nudibranchs : a guide of the opisthobranchs from Alaska to Central America. Monterey, CA: Sea Challengers.
    Benkendorff K. 1999. Bioactive molluscan resources and their conservation: biological and  chemical studies on the egg masses of marine molluscs, xviii. University of  Wollongong. Available from http://www.library.uow.edu.au/adt-NWU/uploads/approved/adt-NWU20011204.154039/public/03Chapter2.pdf.
    Benkendorff K, Davis AR, Bremner J. 2001. Chemical defense in the egg masses of benthic invertebrates: An assessment of antibacterial activity in 39 mollusks and 4 polychaetes. Journal of Invertebrate Pathology 78(2):109-118.
    Bergh LSR. 1876. Beitrage zur Kenntniss der Aeolidiaden, IV. Verhandlungen der koniglich-kaiserlich Zoologisch-botanischen Gesellschaft in Wien (Abhandlungen) 26:737-764, pls. 9-12.
    Bergh LSR. 1881. Ueber die Gattung Idalia, Leuckart. Archiv fur Naturgeschichte 47(1):140-181, pls. 6-8.
    Bergh LSR. 1873. Neue Nacktschnecken der Sudsee, Malacologische Untersuchungen, Journal des Museum Godeffroy 1(2):65-96 137-168, pls. 9-12.
    Bergh LSR. 1871. Beitrage zur kenntnis der Mollusken des Sargassomeeres. Verhandlungen der Kaiserlich-königlichen Zoologisch-botanisch Gesellschaft in Wien, 21: 1273-1306.
    Bergh LSR. 1885. Beitrage zur Kenntniss der Aeolidiaden. VIII. Verhandlungen der koniglich-kaiserlich Zoologisch- botanischen Gesellschaft in Wien (Abhandlungen) 35(1):1-60, pls. 1- 7.
    Bergh LSR. 1868. Anatomiske Bidrag til kundskab om aeolidierne. Det Kongelige Danske Videnskabernes Selskabs Skrifter. Femte Raekke, Naturvidenskabelig og Mathematisk Afdeling Kjobenhavn 7:139-316, pls. I-IX.
    Bergh LSR. 1882. Beitrage zur Kenntniss der Aeolidiaden. VII. Verhandlungen der koniglich-kaiserlich Zoologisch-botanischen Gesellschaft in Wien (Abhandlungen) 32:7-74, pls. 1-6.
    Bergh LSR. 1890. Die cladohepatischen Nudibranchien. Zoologische Jahrbucher, Abtheilung fur Systematik Geographie und Biologie der Thiere 5:1-75.
    Bergh LSR. 1881. Beitrage zur Kenntniss der japanischen Nudibranchien. II. Verhandlungen der koniglich-kaiserlich Zoologisch-botanischen Gesellschaft in Wien (Abhandlungen) 31:219- 254, pls. 6-10.
    Bergh LSR. 1908. Malacologische Untersuchungen, In: Reisen im Archipel der Philippinen von Dr Carl Gottfried Semper. Zweiter Theil. Wissenschaftliche Resultate. Band 9, Theil 6, Heft 3; pp 119-181, pls. 9-12.
    Bergh R. 1892. System der Nudibranchiaten Gasteropoden. Malacologische Untersuchungen. In: Reisen im Archipel der Philippinen von Dr. Carl Gottfried Semper. Zweiter Theil#Wissenschaftliche Resultate. Band 7, Theil 5. [pp. 1–51, pls 1–4, Mar. 1897; pp. 53–115, pls 5–8, Dec. 1897; pp. 117–158, pls 9–12, Nov. 1898; pp. 159–208, pls 13–16, 27 Mar. 1900; pp. 209–256, pls 17–20, 29 Jan. 1901; pp. 257–312, pls. 21–24, 15 Oct. 1901; pp. 313–382, pls 25–29, 7 Oct. 1902].
    Bergh LSR. 1878. Malacologische Untersuchungen, In: Reisen im Archipel der Philippinen von Dr Carl Gottfried Semper. Zweiter Theil. Wissenschaftliche Resultate. Band 2, Theil 2, Heft 14; pp 603-645, I-L, pls. 66-68.
    Berry AJ, Radhakrishnan KV, Coward K. 1992. Is Seasonal Breeding in Retusa obtusa (Montagu) (Gastropoda, Opisthobranchia) Merely the Consequence of Seasonal Breeding in Its Prey, the Mudsnail Hydrobia ulvae (Pennant). Journal of Experimental Marine Biology and Ecology. 159(2):179–189. https://doi.org/10.1016/0022-0981(92)90035-9.
    Bertsch H. 1993. Opistobranquios (Mollusca) de la costa occidental de México, In: , Com Nal. Biodiversidad y CIQRO, México pp.253-270.
    Bertsch H. 1985. An international reconnaissance expedition: marine zoogeography of Baja California Sur. Environment Southwest (San Diego Natural History Museum) (508):18-23.

    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:

Ballesteros, M., Madrenas, E. & Pontes, M. (2023) "Spurilla neapolitana" in OPK-Opistobranquis. Published: 16/05/2012. Accessed: 20/04/2024. Available at (https://opistobranquis.info/en/?p=574)

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