Aglaja tricolorata

Aglaja tricolorata (Renier, 1804)

Aglaja tricolorata by Enric Madrenas




































Aglaja tricolorata  Renier, 1807

 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 138728).

  • Acera marmorata Cantraine, 1841
  • Aglaja taila Marcus Ev. & Er., 1966
  • Doridium meckelii Delle Chiaje, 1824
  • Doridium membranaceum Meckel, 1809

This cephalaspidean can achieve a significant size, up to 70 mm in length. The color of the animal is dark brown with rounded white spots distributed throughout the body. The head shield represents more than half the length of the body and in the anterior part can be differenced two sidelobes whose rear edge is white. The parapodia are broad, almost completely engulfing the head shield. There is a fragile and flattened inner shell. In the caudal area, the mantle has two lobes. From the left lobe protrudes a fine, dark and extensible filament that may reach 4-5 cm in length. The edge of the two caudal lobes and the margin of the caudal filament are usually pigmented white. The foot is very wide and in the anterior part two palps, slightly curved back, can be found. The trailing edge of the foot palps is also pigmented white. The color of the foot is very dark brown, almost black, and bright, with a soft iridescent bluish tint, the upper edge of the foot has white spots somewhat larger than the spots in the rest of the body.

A. tricolorata, as most species of the Aglajidae family, lives in soft substrates of mud or sand and calcareous concretions, between 20 and 45 m depth, where it is well adapted to burrow for food (polychaetes, nemerteans or molluscs). This species, which has no radula, is able to capture and fully engulf its prey with the help of the buccal bulb, which can be projected out. It is possible to find 2 specimens wandering in line with the head region of one attached to the back region of another, it may be a reproductive behavior during copula. The spawn of this species is significant and is formed by a gelatinous mass of elongated circular section amb about 8-10 cm in length, attached to the substrate by a thin cord; spawm structure is hollow and in its periphery has a cord where numerous coiled gelatinous ovigerous capsules, each containing about 4-5 white eggs with a diameter of 188 microns. Because of the underground habits of this species very little is known about its eating habits and other biology details.


  • Aglaja, Greek word meaning “splendor” or “beautiful”
  • Tricolorata, from Latin, meaning “of three colours”.

This is an eminently Mediterranean species, having been located in the Adriatic, Mediterranean France and Malta. In the Iberian Peninsula has been cited in Cabo de Palos (Murcia), in the Strait of Gibraltar and in the Atlantic coast of Huelva. In Catalonia it has been observed in Malgrat (Maresme) and in some other localities of the Costa Brava, such as Tamariu.

Known georeferenced records of the species: Aglaja tricolorata
: 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 Aglaja tricolorata based on our own records.



More pictures


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Further reading

Cite this article as:

Ballesteros, M., Madrenas, E. & Pontes, M. (2023) "Aglaja tricolorata" in OPK-Opistobranquis. Published: 20/05/2012. Accessed: 02/12/2023. Available at (

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