Stylocheilus striatus

Stylocheilus striatus (Quoy & Gaimard, 1832)

Stylocheilus striatus @ El Hierro 17-10-2012 by Aketza Herrero




































Stylocheilus striatus  (Quoy & Gaimard, 1832)

 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 224662).
Taxonomic note: There was a long time discussion about the identity of Stylocheilus longicauda (Quoy & Gaimard, 1825) and Stylocheilus striatus (Quoy & Gaimard, 1832). Unfortunately these authors noted that S. striatus was probably the same as S. longicauda, beginning a confusion which has persisted until the present. Today most researchers consider that there are two species of Stylocheilus: S.striatus, with dark longitudinal lines, a mottled colour pattern and compound papillae, and S.longicauda with a uniform yellow or green colour, simple papillae, without lines and an extremely long slender ‘tail’. Despite these species were clearly differentiated, Yonow (2012) reverted back to the confusion by ignoring evidence presented by Rudman (1999) that they are distinct species..


  • Aplysia striata Quoy & Gaimard, 1832 (original)
  • Notarchus polyomma Mörch, 1863
  • Stylocheilus lineolatus Gould, 1852

Stylocheilus striatus is a medium sized sea slug, reaching up to 65mm, it has a translucent body with patches of greens, browns and white, and often with many branched papillae. This species is distinguished by fine longitudinal brown-to-black lines usually interrupted by ‘eyespots’ with bright blue centres; it has a long tail and a swelling is present in the middle of body, where the parapodial lobes enclose a large gill and an anal siphon. The rhinophores and oral tentacles are long and slender. It may have few or numerous villi, depending on the population. Releases a purple dye when disturbed.

It can be locally common in algal beds and shallow water, especially during the breeding season, but this does not happen every year.


  • Stylocheilus. From Latin “stylus”, column, pillar + from Greek χεῖλος, “cheilos”, lip, edge.
  • Striatus. From Latin “striatus”, striated, grooved.

Circumglobal. Subtropical. There are reports from Australia, Galápagos, Brasil, Caribbean, Philippines, Florida, Hawaii, Cape Verde, Gulf of Mexico, SW India, Maldives, Zanzibar, Mauritius, La Réunion, Mayotte, and Madagascar.

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


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

This chart displays the monthly observation probability for Stylocheilus striatus based on our own records.


Stylocheilus striatus @ Tulamben, Bali by Cix Cutez @ Nudibase (Facebook)


Bloom of Stylocheilus striatus amidst the algae Avrainvillea amadelpha
at 50 meters (Jan 7th, 2015) (YouTube)


Stylocheilus longicauda by Shane Siers (


More pictures


    Bacallado, J. J., J. Ortea, L. Moro, F. J. Martín Barrios, T. Cruz Simó, and R. Mesa Hernández. 2008. Inventario de los moluscos de la marina de Arrecife, Lanzarote. Canarias Conservación. 1–32.
    Ballesteros, M., E. Madrenas, and M. Pontes. 2023. OPK - Opistobranquis. (
    Caballer, M., J. Ortea, N. Rivero, G. Carias-Tucker, M. A. E. Malaquías, and S. Narciso. 2015. The opisthobranch gastropods (Mollusca: Heterobranchia) from Venezuela: an annotated and illustrated inventory of species. Zootaxa 4034 (2): 201–256.
    Camacho-Garcia, Y., T. Gosliner, and A. Valdes. 2005. Guía de Campo de las babosas marinas del Pacífico Este tropical. California Academy of Sciences, S.l.
    Cervera, J. L., G. Calado, C. Gavaia, M. A. E. Malaquías, J. Templado, M. Ballesteros, J. C. García-Gómez, and C. Megina. 2004. An annotated and updated checklist of the opisthobranchs (Mollusca: Gastropoda) from Spain and Portugal (including islands and archipelagos). Boletín Instituto Español de Oceanografía, 20 (1-4): 1-111. L.
    Frank, B. et al. 1998. Stylocheilus striatus accessed through: on 2014-12-14. (
    Goodheart, J. A., R. A. Ellingson, X. G. Vital, H. C. Galvão Filho, J. B. McCarthy, S. M. Medrano, V. J. Bhave, K. García-Méndez, L. M. Jiménez, G. López, C. A. Hoover, J. D. Awbrey, J. M. De Jesus, W. Gowacki, P. J. Krug, and Á. Valdés. 2016. Identification guide to the heterobranch sea slugs (Mollusca: Gastropoda) from Bocas del Toro, Panama. Marine Biodiversity Records. 9: 56.
    Imamoto, J. 2001. Stylocheilus striatus accessed through: on 2014-12-14. (
    Long, S. J. 2006. Bibliography of Opisthobranchia 1554-2000. Bayside Books & Press, Tustin, CA, U.S.A. 672p.
    Malaquias, M. A., and G. J. P. Calado. 1997. The malacological fauna of Salvage Islands - 1. Opisthobranch Molluscs. Bol. Mus. Mun. Funchal, 49(281): 149-170.
    Malaquias, M., G. Calado, V. Padula, G. Villani, and J. L. Cervera. 2009. Molluscan diversity in the North Atlantic Ocean: new records of opisthobranch gastropods from the Archipelago of the Azores. Marine Biodiversity. 2: e38.
    McDonald, G. 2009. Bibliographia Nudibranchia. 2nd Online Edition, Annotated. 1072 pp  Institute of Marine Sciences, University of California, Santa Cruz. (
    Ortea, J., L. Moro, J. J. Bacallado, and J. J. Sanchez. 2008. Nuevas aportaciones a la fauna de opistobranquios (Mollusca: Gasteropoda) de las islas Canarias. Vieraea 36: 129-136. 36: 129–136.
    Ortea, J., J. Espinosa, M. Caballer, and Y. Buske. 2012. Initial inventory of the seaslugs (Opisthobranchia and Sacoglossa) from the expedition Karubentos, held in May 2012 in Guadeloupe (Lesser Antilles, Caribbean Sea). Revista de la Academia Canaria de Ciencias 24: 153-182.
    Quoy, J. R. C., and J. P. Gaimard. 1832. Voyage de découvertes de l’ “Astrolabe” exécuté par ordre du Roi, pendant les années 1826-1829, sous le commandement de M. J. Dumont d’Urville. Zoologie, Tome 2. J. Tatsu.
    Rudman, W. B. 1999. Stylocheilus longicauda & Stylocheilus citrina Nomenclatural discussion. Sea Slug Forum. (
    Rudman W.B. et al. 1998. Stylocheilus striatus accessed through: Sea Slug Forum on 2014-12-14. (
    Valdés, A., J. Hamann, D. W. Behrens, and A. DuPont. 2006. Caribbean sea slugs: a field guide to the opisthobranch mollusks from the tropical northwestern Atlantic. Washington: Sea Challengers Natural History Books. 289 pp.
    Wirtz, P., and H. Debelius. 2003. Mediterranean and Atlantic invertebrate guide. ConchBooks, Hackenheim, Germany.
    WoRMS Editorial Board. 2023. World Register of Marine Species. WoRMS. (
    Yonow, N. 2012. Opisthobranchs from the western Indian Ocean, with descriptions of two new species and ten new records (Mollusca, Gastropoda). ZooKeys. 197: 1–129.

    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) "Stylocheilus striatus" in OPK-Opistobranquis. Published: 19/01/2015. Accessed: 30/03/2023. Available at (

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