Okenia mica

Okenia mica Ortea & Moro, 2014

Okenia mica @ Gran Canaria by Mario Matute

Adult animals do not exceed 3 mm in length. Body shape is limaciform and slender, about 6 times as long as it is wide, with a narrow transparent crest that surrounds the notum, in which there are five translucent white papillae with opaque white spots. The smallest papilla, with a yellow spotted base, is located in front of each rhinophore; three longer papillae are arranged between the rhinophores and the gill, and the fifth, the longest, is located behind the gill. Two large dorsal papillae appear between the rhinophores and the gill, the largest being the one located on the cardiac prominence, in front of the gill. It lacks a frontal veil. The dorsal coloration of the body is whitish, with more or less diffused reddish spots that form a large spot behind the rhinophores. The sides of the body have red and white spots, more abundant towards the tail. Rhinophores proportionally large compared to the size of the animal, with a white distal mucron and 4-5 lamellae on the upper half, spotted red and all similarly sized. The lower half of the rhinophores is smooth with reddish spots. The head has two cylindrical oral tentacles with white ends. The gill is small, made up of three branchial leaves of the same color as the body; the central leaf is bipinnate and the lateral ones are unipinnate. The mantle has a structure of spicules related to the dorsal papillae, the gill and the paleal crest, the sides of the body have no spicules except under the eyes.

The egg spawn is a cord of 0.5 mm in diameter folded on itself with white eggs of about 80 μm in diameter. The eggs form transverse lines of 5-6 eggs, arranged in 2-3 layers inside the cord. The specimens used for its description were collected from a submerged line at a depth of about 2 meters, and among the bryozoans of a submerged wall at a depth of about 4 meters.


  • mica, from Latin mica-ae, crumb, particle, because of its small size.

This species has only been cited in the Canary Islands, in Tenerife (specimens of the original description), Gran Canaria and Lanzarote.

Known georeferenced records of the species: Okenia mica
: 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 Okenia mica based on our own records.

More pictures


    Ballesteros, M., E. Madrenas, and M. Pontes. 2023. OPK - Opistobranquis. (https://opistobranquis.info/).
    Ortea, J., L. Moro, J. J. Bacallado, and J. M. Caballer. 2014. Nuevas especies y primeras citas de babosas marinas (Mollusca: Opisthobranchia) en las islas Canarias y en otros archipiélagos de la Macaronesia. Vieraea. 42: 47-77.
    Ortea, J., L. Moro, and J. J. Bacallado. 2015. Babosas Marinas Canarias. Turquesa Ediciones.
    WoRMS Editorial Board. 2023. World Register of Marine Species. WoRMS. (http://www.marinespecies.org).

    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:

Pontes, Miquel (2023) "Okenia mica" in OPK-Opistobranquis. Published: 19/01/2023. Accessed: 04/06/2023. Available at (https://opistobranquis.info/en/wQOB2)

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