Placida verticilata

Placida verticilata Ortea, 1982

Placida verticilata by Enric Madrenas




































Placida verticilata  Ortea, 1982

 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 141568).
The specimens of this species tend to measure between 7 and 10 mm in length. The background body color is whitish but it is masked by the greatly developed diverticulae of the digestive gland, branching throughout the body (back, head, body sides, rhinophores, anal papilla, cerata and foot) and, being filled with chloroplasts, provide an olive green coloration to the entire animal. The rhinophores are thin and long and they are grooved along their front side. The eyes are inconspicuous and are located right behind the base of rhinophores. The anal papilla is tubular, long and narrow and is located ahead of the heart area, right below the first dorsal cerata. The digestive gland branches extraordinarily throughout the body sometimes not allowing to distinguish the main hepatic ducts. There are about 30-40 cerata on the back, they are elongated and fusiform and have a rounded tip; within each cerata there is a thick olive green hepatic duct that alternately grows rounded short ramifications of the same colour to one side and another. The foot is whitish and rounded ahead, where it forms two rounded lateral lobes.

Morphological note: P. verticilata is very similar to P. dendritica, there are distinguished by longer and simply grooved rhinophores -they are auriculate and rolled in P. dendritica– and the ramifications of the digestive gland within the cerata, in P. verticilata they are simple and convoluted, while in P. dendritica they are complexely branched.

This kind of sacoglossan lives, as the similar species P. dendritica on the thalli of the branched chlorophycean algae of the genus Codium, on which it feeds and with which it keeps a perfect color mimicry. As in other sacoglossans, it does not digest the ingested chloroplasts from the algae but they are accumulated instead in the complex ramifications of the digestive gland. These chloroplasts are kept functional for several weeks, and as they perform photosynthesis, they synthesize organic compounds, to the advantage of the sacoglossan. The spawn consists of a tightly wrapped flattened ribbon forming a flat spiral; Eggs are white and they are enclosed in nearly spherical egg capsules of about 140 microns in diameter (Ortea, 1981; Garcia-Gomez, 1987).


  • Placida. From Latin “placeō”, please, satisfy. Also means placid, gentle, quiet, still, calm, mild, peaceful.
  • Verticilata. From Latin “verticillus”, meaning “with whorls.” Because of the whorled layout of the digestive branches in the cerata. In biology a whorl is a set of three or more leaves, branches or other organs sprouting from a base at the same level.

This is a species that has been cited so far in the coasts of the English Channel (Muller, 2004), the Canary Islands, Azores, Madeira (Borges et al. 2010), the Iberian Peninsula and the Caribbean (Costa Rica, Cuba; Miloslavich et al, 2010). In the Iberian Peninsula (Cervera et al. 2004) it has been reported on the Cantabrian coast, in Portugal, Strait of Gibraltar and the Andalusian Mediterranean. In Catalonia it has been recently observed in different parts of the Costa Brava (Medes Islands, Cala Aiguafreda, Tossa de Mar). Possibly its range is wider, as it has been probably misidentified with Placida dendritica due to the similarity of their morphology, color and substrate.

Known georeferenced records of the species: Placida verticilata
: 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 Placida verticilata based on our own records.

More pictures


    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
    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, Madrenas E, Pontes M. 2023. OPK - Opistobranquis. Available from
    Caballer M, Ortea J, Rivero N, et al. 2015. The opisthobranch gastropods (Mollusca: Heterobranchia) from Venezuela: an annotated and illustrated inventory of species. Zootaxa 4034 (2): 201–256.
    Calado G, Malaquias M, Gavaia C, et al. 2003. New data on opisthobranchs (Mollusca: Gastropoda) from the southwestern coast of Portugal. Boletín Instituto Español de Oceanografía 19 (1-4): 199-204.
    Cervera JL, Calado G, Gavaia C, et al. 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.
    Long SJ. 2006. Bibliography of Opisthobranchia 1554-2000. Bayside Books & Press, Tustin, CA, U.S.A. 672p.
    McDonald G. 2009. Bibliographia Nudibranchia. 2nd Online Edition, Annotated. 1072 pp  Institute of Marine Sciences, University of California, Santa Cruz. Available from
    Moro L, Bacallado JJ, Ortea JA. 2010. Babosas marinas de las islas Canarias. Actas VI Semana Científica Telesforo Bravo, Instituto de Estudios Hispánicos de Canarias.
    Moro L, Wirtz P, Ortea J, et al. 2000. Cuatro nuevas especies anfiatlánticas del Orden Sacoglossa (Mollusca, Opisthobranchia).
    Moro L, Martín Esquivel JL, Garrido Sanahuja MJ, et al. 2003. Lista de especies marinas de Canarias (algas, hongos, plantas y animales). Consejería de Política Territorial y Medio Ambiente del Gobierno de Canarias. 248 p.
    Ortea J. 1981. Moluscos opistobranquios de las Islas Canarias Parte I: Ascoglosos. Boletín del Instituto Español de Oceanografía 6: 180-199.
    Ortea J. 1981. Moluscos Opistobranquios de las Islas Canarias. Primera parte: Ascoglosos. Boletín del Instituto Español de Oceanografía. 6(4): 180-199.
    Ortea J, Moro L, Bacallado JJ. 2015. Babosas Marinas Canarias. Turquesa Ediciones.
    Parera A, Pontes M, Salvador X, et al. 2020. Sea slugs (Mollusca, Gastropoda, Heterobranchia): the other inhabitants of the city of Barcelona (Spain). Butlletí de la Institució Catalana d’Història Natural, 84: 75-100.
    Pontes M, Salvador X, Parera A, et al. 2021. Biodiversity in anthropized marinas. The case of the Barcelona Forum bathing area (Spain). Barcelona: Institució Catalana d’Història Natural (Monografies de la Societat Catalana d’Història Natural). 68 p.
    Prkić J, Petani A, Iglić Ð, et al. 2018. Stražnjoškržnjaci Jadranskoga Mora: Slikovni Atlas i Popis Hrvatskih Vrsta / Opisthobranchs of the Adriatic Sea: Photographic Atlas and List of Croatian Species. Bibinje: Ronilaćki Klub Sveti Roko. 464 p. Available from
    Sánchez Tocino L. 2001. Placida verticillata accessed through: Opistobranquios de la Costa de Granada on 2014-12-14. Available from
    Sánchez-Tocino L. 2018. El Litoral de Granada - Opistobranquios. El Litoral de Granada. Available from
    Templado J, Villanueva R. 2010. Checklist of Phylum Mollusca. pp. 148-198 In Coll, M., et al., 2010. The biodiversity of the Mediterranean Sea: estimates, patterns, and threats. PLoS ONE 5(8):36pp.
    Trainito E, Doneddu M. 2014. Nudibranchi del Mediterraneo. 2nd. Il Castello. 192 p.
    WoRMS Editorial Board. 2023. World Register of Marine Species. WoRMS. Available from

    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) "Placida verticilata" in OPK-Opistobranquis. Published: 17/07/2012. Accessed: 05/03/2024. Available at (

To copy this cite click on the right button.