Lomanotus barlettai

Lomanotus barlettai  García-Gómez, López-González & García, 1990

Lomanotus barlettai by José Carlos García Gómez










































Lomanotus barlettai  García-Gómez, López-González & F. J. García, 1990

 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 140272).
Body elongated and narrow, small sized (about 5mm) and coloured brown, with a large number of brown or golden yellow surface spots, less dense in some irregularly distributed areas, which acquire a dark -almost black- appearance. It has up to 36 cerata arranged vertically in three pairs of curved crests located contiguously from the back of the rhinophoral sheaths to the caudal region, forming a characteristic ripple on each side of the notum. In front of the first pair of dorsal crests there are two small cerata facing outwards. In the dorsal crests the larger cerata correspond to those that are in the most dorsal position. The cerata are digitiform, wider at their base, with one or two constrictions and with a rather large apex. The cerata coloration follows the pattern of the body, but the amount of golden scores is smaller than in the rest of the body. The frontal veil is rounded and has two processes aimed at each side of the body, the shortest of which is in the inner position. The rhinophores are elongated (a quarter of the total length of the body) and have 8 to 9 inclined lamellae. The apex of the rhinophores extends slightly beyond the apical end of the rhinophoral sheaths. There is a small ridge on the back of each rhinophore. Rhinophoral sheaths are high and have two constrictions that favor a very characteristic central thickening. The rim of the rhinoform sheath is cup-shaped and has 6 or 7 processes similar to the cerata, with one or two constrictions, a broad base and a slightly bulging apex. Dorsally, in the cephalic region, there is a small tuberculate ridge arranged longitudinally that continues between the rhinophores to the beginning of the dorsal crest. The raised and wrinkled-looking pericardial area is located between the first and second pair of dorsal ridges. There could be a series of dorsal tubercles between the second and third dorsal ridge. The forefoot is broad, with two marked lobes, while the back of the foot is short and tappered. The genital pore is on the right side of the animal, between the rhinophore and the first dorsal ridge. The anus and renal pore are not visible in the studied specimens.

The specimens of this dendronotid are extremely cryptic on the substrate in which it is found: calcareous stones of sedimentary origin. It has been found in the intertidal zone near the Kirchenpaueria pinnata and Ventromma halecioides hydroids from which it is supposed to feed, although it has not been possible to observe this fact (García Gómez et al., 1990). The specimens found in Croatia were found 20 meters deep on the algae Cystoseira sp. close to hydroids of the Plumularioidea superfamily (Trainito et al., 2017). Its ability to live unnoticed is excellent because it allows small particles of the sediment to adhere to the cerata and rhinophores as part of its camouflage.


  • Lomanotus. From Greek “loma”, ridge, edge  + “noton”, back.
  • Barlettai. In honor to the Italian malacologist Giorgio Barletta, 1938-1988, who published Malacofauna del Mar Rosso in 1970.

It is an apparently rare species, but its abilities to camouflage with its habitat make it probably unnoticed. The first specimens were described on the coast of Huelva, Spain (García Gómez et al., 1990), having been cited later in the Costa Brava, Spain (L’Escala and Aiguafreda) in 2014 (Ballesteros et al., 2016) and Labin , Croatia in 2016 (Trainito et al., 2017). It has been recently found in Gran Canaria (Taliarte) on 08/08/2017 (Jose Juan Calderín Peñate, pers. comm.), the first report for the Canary Islands.

Known georeferenced records of the species: Lomanotus barlettai
: 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 Lomanotus barlettai based on our own records.



More pictures


    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, Pontes M, Madrenas E. 2019. Els nudibranquis del mar català. Figueres: Brau Edicions. 192 p.
    Ballesteros M, Madrenas E, Pontes M. 2024. OPK - Opistobranquis. Available from https://opistobranquis.info/.
    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.
    Garcia FJ, Bertsch H. 2009. Diversity and distribution of the Gastropoda Opisthobranchia from the Atlantic Ocean: A global biogeographic approach. Scientia Marina. 73(1):153–160. https://doi.org/10.3989/scimar.2009.73n1153.
    García-Gómez JC. 2002. Paradigmas de una fauna insólita; Los moluscos opistobranquios del estrecho de Gibraltar (Serie Ciencias) 20: 397 pp. Instituto de Estudios Gibraltareños. Algeciras, Cádiz, Spain.
    García-Gómez JC, López-González PJ, García FJ. 1990. Lomanotus barlettai, a new species of nudibranch mollusk from the Iberian littoral, with remarks on world species of the genus. Canadian Journal of Zoology 68: 2299-2305.
    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 http://escholarship.org/uc/item/8115h0wz.
    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 https://opistobranquis.info/en/recursos/llibres-recomanats/opisthobranchs-of-the-adriatic-sea/.
    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.
    Templado J, Guerra A, Bedoya J, et al. 1993. Fauna marina circalitoral del sur de la Península Ibérica; Resultados de la campaña oceanográfica “Fauna I”. Madrid, Spain: Museo Nacional de Ciencias Naturales (CSIC). 166 p.
    Trainito E, Doneddu M. 2014. Nudibranchi del Mediterraneo. 2nd. Il Castello. 192 p.
    Trainito E, Mas G, Fernández R, et al. 2017. First record of Lomanotus barlettai García-Gómez, López-González & García, 1990 (Gastropoda: Heterobranchia: Nudibranchia) from the Adriatic Sea: remarkable range extension in the Mediterranean Sea. Studia Marina 2017, 30 (1): 28 - 33. https://doi.org/10.5281/zenodo.820513.
    WoRMS Editorial Board. 2023. World Register of Marine Species. WoRMS. Available from 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:

Ballesteros, M., Madrenas, E. & Pontes, M. (2023) "Lomanotus barlettai" in OPK-Opistobranquis. Published: 12/11/2014. Accessed: 18/05/2024. Available at (https://opistobranquis.info/en/?p=16624)

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