Tritonia lineata

Tritonia lineata Alder & Hancock, 1848

Tritonia lineata by Enric Madrenas

Class: Gastropoda  Cuvier, 1797
Subclass: Heterobranchia  J.E. Gray, 1840
Clade: Euthyneura  Spengel, 1881
Clade: Nudipleura  Wägele & Willan, 2000
Order: Nudibranchia  Cuvier, 1817
Suborder: Dexiarchia  Schrödl, Wägele & Willan, 2001
Infraorder: Cladobranchia Willan and Morton, 1984
Parvorder: Dendronotida Odhner, 1934
Superfamily: Tritonioidea  Lamarck, 1809
Family: Tritoniidae  Lamarck, 1809
Genus: Tritonia  Cuvier, 1797
Species: Tritonia lineata (Alder & Hancock, 1848)

This nudibranch can reach more than 30 mm in length. The body is long and narrow, with a square section. The body colour is a slightly translucent whitish, revealing creamy coloured organs through the body integument. Two opaque white lines run along the margins of the dorsum and are inserted into the bases of the pallial processes and, deppending on the specimens, there may also be two parallel longitudinal lines crossing the center of the dorsum and having connections to the side lines near the pallial processes. The two white lines on the sides join ahead of the rhinophores in the head, and also in the back of the tail, which is long and sharp. The oral veil is not very developed and has 4 palps, the one on the center are the longest. The tip of the oral veil extensions is also coloured opaque white. The rhinophores have a thick main portion pigmented white while the lamellae are semitransparent and directed forward. The rhinophoric sheath is expanded and with a wavy upper edge. The eyes are on the rear base of the rhinophores. The margins of the dorsum have about 4 to 5 pallial semitransparent and slightly branched processes, with the central axis coloured opaque white; the last two of these pallial processes are very small and rudimentary. The foot is narrow and with a rounded front.

This species has been found living under stones or on rock walls with abundant algae, hydrarians and anthozoans. It is reported that it feeds on hydrozoan Kirchenpaueria pinnata and the stoloniferous octocorals Sarcodictyon catenatum and S. roseum (Bielecki, 2011). The spawn is a semitransparent ribbon wound in an spiral of about 4 turns with white eggs (Alder & Hancock, 1848).


  • Tritonia. The genus Tritonia is dedicated to Triton, in Greek mythology the god of the sea, son of Poseidon and Amphitrite, portrayed as having the head and trunk of a man and the tail of a fish.
  • Lineata. From Latín “lineatus”, with lines, lined.

This is an European species that, until recently, it was only known from Atlantic waters of northern Europe (British Isles, Norway). First observed for the Iberian Coast at L’Escala (Costa Brava) by Enric Madrenas (Ballesteros, 2007). Later on it has been located on the beach in Temperán (Ria de Vigo, Pontevedra) (Fernández, 2012 ), on the coast of Croatia (Sea Slug Forum) and the Medes Islands (Costa Brava, VIMAR Group).

Known georeferenced records of the species: Tritonia lineata
: 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 observation probability for Tritonia lineata based on our own records.

More pictures


Further reading

Cite this article as:

Ballesteros, Manuel, Enric Madrenas, Miquel Pontes et al. (2012-2017) "Tritonia lineata" in OPK-Opistobranquis, Published: 16/05/2012, Accessed: 18/12/2017 at (

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