Plocamopherus tilesii

Plocamopherus tilesii  Bergh, 1877

Plocamopherus tilesii @ Cambodia 13-10-2016
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Plocamopherus tilesii  Bergh, 1877

 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 531069).
It reaches a maximum reported length of 12cm. The body is oval shaped with the anterior side rounded. It has a translucent, yellowish background color and the whole body is homogeneously speckled with regular black and white spots, some of which are ocellate. There are yellow patches of irregular in size distributed over the entire body, usually associated with papillae. There are also large brownish spots that are fewer in number. The oral veil is wide and flattened, the margin lined with a yellow or orange coloration, and bears 12-15 black, short and somewhat flattened papillae, where the outermost are the largest, with a series or large spots on the base of each papilla, which seem to be exclusive for this species. Rhinophores are bent, triangular, with a lamellate club, brownish with a white dorsal keel and white tips. The rhinophoral sheaths are short and have large, irregular, black spots on the margin. It has five tripinnate branchial gills standing out on the centre of the back, colored brown internally and decorated externally with black and yellow dots. There are three pairs of short lateral appendages, with the last two pairs, flanking the gills, having a prominent globular structure that is white in color. The anterior part of the foot sole is brown, while the rest is yellowish. There are tiny black dots along the foor margin. The rear portion of the foot is short and flattened forming a keel that has a small crest with small marginal papillae. Between the foot sole and the body wall there is a series of transverse very narrow lamellae, most distinct anteriorly and almost indistinguishable posteriorly, that seems to occur only in this species. The anal papilla is prominent, with a papillose yellow tip. The genital opening, which is not prominent and located in the anterior third of the body (close to the head veil) is surrounded by three black spots.

It reportedly feeds on bryozoans (Rudman, 1999) or branching hydroids (Behrens, 2006 @ The Slug Site), deppending on the authors. It also has the ability to burrow itself in the sand, that suggests that it may be a soft-bottom dwelling nudibranch, the enlarged oral veil probably used to sense food. It has the ability to swim away when disturbed: it apparently controls the altitude with its broad flat head, tipping it back at 45 degrees until it reaches about 0.5m above the bottom, then setting it into a flatter posture and continued swimming by to producing vigorous lateral movements using its large flat tail (Holmes, 2002 in Sea Slug Forum). The knob shaped paired appendages on the rear side of the body may, at least in Plocamopherus imperialis and P. ceylonicus, flash a bright luminescent light when disturbed. How the light is produced, whether by light emitting bacteria or some other process is unknown. According to Vallés and Gosliner (2005) it is important to note that it may not have been observed in the wild because although a stimulation provokes the animal into swimming and emitting light, when the animal is stressed or receives a continuous mechanical stimulation it stops emitting light, suggesting that there is some kind of product that it stores, that is used for the light emission and therefore its availability is limited (Wilbur & Yonge, 1966). It is possible that since these animals emit light only when disturbed and for a short span of time, the role could be to temporally distract the attention of potential predators (Wilbur & Yonge, 1966).


  • Plocamopherus. From Greek “plokamos”, hair tress + “-pherus”, from Latin “fero”, a combining form meaning “bearing”, “producing”, “yielding”, “containing”, “conveying” used in the formation of compound words.
  • Tilesii. In honor to the German physician, naturalist and artist Dr. Wilhelm Gottlob Tilesius von Tilenau (1769-1857), who had followed von Krusenstern on the first Russian circumnavigation.

It is distributed throughout the western Indo-Pacific, where it is known from Japan, China, Phillippines, Papua New Guinea, Eastern and Western Australia (Bergh, 1877; Rudman & Darvell, 1990; Wells & Bryce, 1993; Rudman, 1998; Kohler, 2002; Debelius & Kuiter, 2007) also in the Arabian Sea. There’s also a report from the gulf of Iskenderun, Turkey (Yokeş et al., 2012), the first for the Mediterranean Sea. The absence of this species in the Western Indian Ocean malacofauna suggests that ship-mediated transportation from Western Pacific to Eastern Mediterranean seems to be most possible way of introduction (Yokeş et al., 2012).

Known georeferenced records of the species: Plocamopherus tilesii
: 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 Plocamopherus tilesii based on our own records.


Plocamopherus tilesii @ Philippines by Shane Siers (Macronesia)


Plocamopherus tilesii @ Cambodia by Jeerapong Prathomsup


More pictures


    Abe T. 1966. List of the Opisthobranchia from Toyama Bay and vicinity. Edited by The Biology Club Takaoka Senior High School, Toyama Pref; pp 1-13, 1 pl.
    Abe T. 1964. Opisthobranchia of Toyama Bay and adjacent waters, collected and figured mainly by the members of the Biological Club, Takaoka Senior High School, Toyama Pref. Described, with an introduction by Takeo Abe. Supervised by Kikutaro Baba. Edited by the Biological Club, Takaoka Senior High School, Toyama Pref. ix + 99 pp.; maps, tbls.; figs. 1-43, 36 pls. Hokuryu-kan, Tokyo.
    Abraham PS. 1876. Note sur un nouveau mollusque nudibranche du genre Plocamopherus. Bulletin de la Societe Zoologique de France 1:287-290.
    Amio M. 1963. A comparative embryology of marine gastropods, with ecological considerations. The Journal of the Shimonoseki University of Fisheries 12:15-144.
    Arakawa KY. 1960. Miscellaneous notes on Mollusca (2). Mating and spawning habits of some marine molluscs. Venus 21(1):72-78.
    Arakawa KY. 1962. Miscellaneous notes on Mollusca (3). Venus 22(2):173-175.
    Baba K. 1958. Seashore life of Japan. 148 pp, 5 pls. Hokuryukan Co. Ltd., Tokyo.
    Baba K. 1930. Studies on Japanese nudibranchs (1). Polyceridae. Venus 2(1):4-9.
    Baba K. 1957. A revised list of the species of Opisthobranchia from the northern part of Japan, with some additional descriptions. Journal of the Faculty of Science, Hokkaido University, Ser. 6, Zoology, 13(1-4): 8-14.
    Baba K. 1955. Opisthobranch fauna in the vicinity of the Sado Marine Biological station, Sado Island, Japan Sea side. Collecting & Breeding Saishu to Shiiku 65–6).
    Baba K. 1938. Opisthobranchia of Kii, middle Japan. Journal of the Department of Agriculture, Kyushu Imperial University 6(1):1- 19.
    Baba K. 1933. Preliminary note on the Nudibranchia collected in the vicinity of the Amakusa Marine Biological Laboratory. Annotationes Zoologicae Japonenses 14(1):165-179.
    Baba K. 1937. Opisthobranchia of Japan (I). Journal of the Department of Agriculture, Kyushu Imperial University 5(4):195-236, pl 4.
    Baba K. 1935. Report on the biological survey of Mutsu Bay (27) Nudibranchia of Mutsu Bay. Science Reports Tohoku Imperial University, series 4, Biology 10(2):331-360, pls. 5-7.
    Baba K. 1949. Opisthobranchia of Sagami Bay collected by His Majesty The Emperor of Japan. 194 pp, 50 pls. Iwanami Shoten, Tokyo.
    Baba K. 1937. Opisthobranchia of Japan (II). Journal of the Department of Agriculture, Kyushu Imperial University 5(7):289-344, pls. 1-2.
    Baba K, Hamatani I. 1952. List of the species of the Opisthobranchia from Kii, Middle Japan. Nanki-Seibutsu Supplement, Nanki Biological Society, Wakayama (1):1-11.
    Ballesteros M, Madrenas E, Pontes M. 2023. OPK - Opistobranquis. Available from
    Bergh LSR. 1876. Malacologische Untersuchungen, In: Reisen im Archipel der Philippinen von Dr Carl Gottfried Semper. Zweiter Theil. Wissenschaftliche Resultate. Band 2, Theil 2, Heft 10; pp 377-427, pls. 49-53.
    Bergh LSR. 1879. Beitrage zu einer Monographie der Polyceraden, I. Verhandlungen der koniglich-kaiserlich Zoologisch-botanischen Gesellschaft in Wien (Abhandlungen) 29:599- 652, pls. 9-14.
    Bergh LSR. 1877. Malacologische Untersuchungen, In: Reisen im Archipel der Philippinen von Dr Carl Gottfried Semper. Wissenschaftliche Resultate. Band 2, Theil 2, Heft 11; pp 429-494, pls. 54-57.
    Bergh LSR. 1880. Beitrage zur Kenntniss der japanischen Nudibranchien. I. Verhandlungen der koniglich-kaiserlich Zoologisch-botanischen Gesellschaft in Wien (Abhandlungen) 30:155- 200, pls. 1-5.
    Bergh LSR. 1890. Die Nudibranchien des “Sunda-Meeres”. Malacologische Untersuchungen. In:  Reisen im Archipel der Philippinen von Dr. Carl Gottfried Semper. Zweiter Theil.
    Bergh LSR. 1881. Beitrage zu einer Monographie der Polyceraden, II. Verhandlungen der koniglich-kaiserlich Zoologisch-botanischen Gesellschaft in Wien (Abhandlungen) 30:629- 668, pls. X-XV.
    Bergh LSR. 1883. Beitrage zu einer Monographie der Polyceraden. III. Verhandlungen der koniglich-kaiserlich Zoologisch-botanischen Gesellschaft in Wien (Abhandlungen) 33:135- 180, pls. 6-10.
    Bergh LSR. 1908. Malacologische Untersuchungen, In: Reisen im Archipel der Philippinen von Dr Carl Gottfried Semper. Zweiter Theil. Wissenschaftliche Resultate. Band 9, Theil 6, Heft 3; pp 119-181, pls. 9-12.
    Bergh R. 1892. System der Nudibranchiaten Gasteropoden. Malacologische Untersuchungen. In: Reisen im Archipel der Philippinen von Dr. Carl Gottfried Semper. Zweiter Theil#Wissenschaftliche Resultate. Band 7, Theil 5. [pp. 1–51, pls 1–4, Mar. 1897; pp. 53–115, pls 5–8, Dec. 1897; pp. 117–158, pls 9–12, Nov. 1898; pp. 159–208, pls 13–16, 27 Mar. 1900; pp. 209–256, pls 17–20, 29 Jan. 1901; pp. 257–312, pls. 21–24, 15 Oct. 1901; pp. 313–382, pls 25–29, 7 Oct. 1902].
    Bergh LSR. 1878. Malacologische Untersuchungen, In: Reisen im Archipel der Philippinen von Dr Carl Gottfried Semper. Zweiter Theil. Wissenschaftliche Resultate. Band 2, Theil 2, Heft 14; pp 603-645, I-L, pls. 66-68.
    Bertsch H. 1993. Japanese contributions to opisthobranch research, with special reference to Takeo Abe, Iwao Hamatani, and Kikutaro Baba. Western Society of Malacologists, Annual Report 25:15-24.
    Bertsch H, Johnson S. 1981. Hawaiian nudibranchs, a guide for SCUBA divers, snorkelers, tidepoolers, and aquarists, 112 pp. Oriental Publishing Co., Hawaii.
    Bielecki S, Cavignaux G, Crouzet JM, et al. 2011. Des limaces de rêve.
    Çevik C, Gündoğdu S. 2016. Marine mollusca of Mediterranean coast of Turkey. Turkish Marine Research Foundation 43: 184-197.
    Coleman N. 2001. 1001 Nudibranchs. Catalog of the Indo-Pacific Sea Slugs. 144p, 1700 clr. photos. Springwood, Qld.: Neville Coleman’s Underwater Geographic.
    Debelius H, Kuiter RH. 2007. Nudibranchs of the world. Frankfurt: IKAN- Unterwasserarchiv. 360 pp. p.
    Eliot CNE. 1913. Japanese nudibranchs. Journal of the College of Science, Imperial University Tokyo, 35: 1-47, pls. 1-2.
    Eliot CNE. 1906. Report upon a collection of Nudibranchiata from the Cape Verde islands, with notes by C. Crossland. Proceedings of the Malacological Society of London l7(3): 131-159.
    Hamann JC, Farmer WM. 1988. Two new species of Plocamopherus from the western warm water Atlantic. Veliger 31(1-2):68-74.
    Hong SY, Park KY, Park CW, et al. 2006. Marine invertebrates in Korean coasts. Republic of Korea, Academy Publishing Company, Inc. 479 p.
    Imamoto J. 2001 2014. Plocamopherus tilesii accessed through: on 2014-12-14. Available from
    Jensen KR. 2000. Anatomy of some subtidal Opisthobranchia (Mollusca: Gastropoda) from Hong Kong waters. In: Morton B, editor. Proceedings of the Tenth International Marine Biological Workshop: The Marine Flora and Fauna of Hong Kong and Southern China V pp 157-181. Hong Kong University Press.
    Jung D, Lee J, Kim C. 2013. A report on species of phyllidiid and polycerid nudibranch including two species new to Korea. Journal of Species Research, 2(1):7-14.
    Liu JY. 2008. Checklist of marine biota of China seas. China Science Press. 1267 p.
    Long SJ. 2006. Bibliography of Opisthobranchia 1554-2000. Bayside Books & Press, Tustin, CA, U.S.A. 672p.
    Marcus E d. BR. 1979. Campagne de la Calypso au large de cotes Atlantiques de l’Amerique du sud (1961-1962). I. 31. Mollusca Opisthobranchia. Annales de l’Institut Oceanographique, Monaco 55(suppl):131-137.
    McDonald G. 2009. Bibliographia Nudibranchia. 2nd Online Edition, Annotated. 1072 pp  Institute of Marine Sciences, University of California, Santa Cruz. Available from
    Nakano R. 2016. Natural feeding habits of two nudibranchs: Kalinga ornata and Plocamopherus tilesii (Nudibranchia: Doridacea: Polyceridae). Molluscan Research.
    Okada YK, Baba K. 1938. On the luminous organs of a nudibranch, Plocamophorus tilesii Berge. Annotationes Zoologicae Japonenses 17(3,4):276-279, pl 15.
    Okutani T. 2000. Marine mollusks in Japan, xlviii. Tokai University Press. 1173 p.
    Ono A. 2004. Opisthobranchs of Ryukyu Islands. Rutles Inc., Japan.
    Ono A. 1999. Opisthobranchs of Kerama Islands. TBS Tokyo 184p.; 500+ photos.

    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, Manuel Ballesteros, Enric Madrenas (2023) "Plocamopherus tilesii" in OPK-Opistobranquis. Published: 21/12/2018. Accessed: 02/03/2024. Available at (

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