Lomanotus genei

Lomanotus genei Vérany, 1846

Lomanotus genei by Bernard Picton

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: Lomanotidae  Bergh, 1890
Genus: Lomanotus  Vérany, 1844
Species: Lomanotus genei  Vérany, 1846


  • Lomanotus berghi Graeffe, 1902
  • Lomanotus eisigi Trinchese, 1883
  • Lomanotus hancocki Norman, 1877
  • Lomanotus portlandicus Thompson W., 1859
  • Lomanotus varians Garstang, 1889

Adults often reach 60 mm in length although there is a report of a 94mm specimen. The body color is variable and could range from translucent white to red, but the most characteristic feature of this rare nudibranch are the pallial processes, similar to cerata, tipped in yellow, running along each side of the wavy mantle border. In juveniles these pallial processes are arranged separatedly, but in adults they are grouped forming a continuous strip around the wavy edge of the mantle. In the anterior part of the foot there are two pairs of tentacles. The rear end of the foot is colored opaque yellow. The genital papilla is located on the right side of the body, at the height of the rhinophores. These rhinophores are smooth on the first two thirds of its length while the terminal third are lamellated, being protected by rhinophoric sheaths whose edges have some yellow tipped protuberances, looking like petals, and give them a similar appearance to the other bodily processes. Juveniles of this species can be confused with similar species Lomanotus marmoratus, whose specimens are smaller in size, have a beige colored body and do not have yellow tipped body processes.

According to Thompson & Brown (1984) Lomanotus genei feeds on the branched hydrarian Nemertesia ramosa, which grows in coastal rocky areas at depths down to 90m. It has not been possible to establish a relationship between its food and the body color, so it is probably a genetic trait. Spawning takes place between March and mid-May, and consists of a string of pale yellow eggs, arranged irregularly around the branches of the hydrarian. This nudibranch can be parasitized, both internally and externally, by the copepod Lomanoticola insolens T. & A. Scott, 1895, which also parasitizes the similar species Lomanotus marmoratus. Under normal conditions it moves slowly but when threatened it can move with swimming movements produced by the lateral undulation of the body.


  • Lomanotus. From Greek “Loma”= edge, fringe  and “notus”= back; with reference to the undulating mantle edge.
  • Genei. Dedicated to Carlo Giuseppe Gene (1800-1847), naturalist of the University of Pavia (Italy), who published works on entomology. Travelled to Hungary and Sardinia to collect insects.

This animal is found around the British Isles, on the French Atlantic coast and in the Mediterranean, where it is very rare and it has only been reported sporadically in Italy, Croatia and now also in Catalan waters in the Iberian Peninsula.

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

References for the species: Lomanotus genei

    General: Bergh, 1879:555; 1882:66; Brown & Picton, 1979:4; Eliot, 1906c:350; 1910d:115[P]; Gamble, 1892:379; Garstang, 1890:425; Grieg, 1913a:7; Hayward, Wigham, & Yonow, 1990:709; Nordsieck, 1972:67; Picton & Morrow, 1994:32[P]; Pruvot-Fol, 1951:51; 1954b:364; Riedl, 1970:429; Sabelli, Giannuzzi-Savelli, & Bedulli, 1990:445; Schmekel, 1970:181; Schmekel & Portmann, 1982:152; Thompson, 1988:118; Thompson & Brown, 1984:18[P]; Vayssiere, 1901a:87; 1913a:264; Verany, 1846:22; 1846a:102; 1849:593; 1850:89; Walton, 1908:236

    Sources: Cervera et al., 2004, Ballesteros, 2007, McDonald, 2006 and other sources.


    Western Mediterranean:
    Eastern Mediterranean:
    Atlantic Ocean:
This chart displays the observation probability for Lomanotus genei based on our own records.

More pictures

    We have no (more) pictures for Lomanotus genei


Further reading

Cite this article as:

Pontes, Miquel, Manuel Ballesteros, Enric Madrenas et al. (2012-2017) "Lomanotus genei" in OPK-Opistobranquis, Published: 19/09/2014, Accessed: 23/11/2017 at (http://opistobranquis.info/en/8N8gw)

In order to copy this cite or text fragments you must be a registered user.