Eubranchus exiguus

Eubranchus exiguus (Alder & Hancock, 1849)

Eubranchus exiguus by Bernard Picton

Taxonomy
 

Superdomain

Biota  

 

Kingdom

Animalia  

 

Phylum

Mollusca  

 

Class

Gastropoda  

 

Subclass

Heterobranchia  

 

Infraclass

Euthyneura  

 

Subterclass

Ringipleura  

 

Superorder

Nudipleura  

 

Order

Nudibranchia  

 

Suborder

Cladobranchia  

 

Superfamily

Fionoidea  

 

Family

Eubranchidae  

 

Genus

Eubranchus  

 

Species

Eubranchus exiguus  (Alder & Hancock, 1848)

 
 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 139765).

Taxonomic note: The phylogenetic analyses performed by Cella et al. (2016) revealed that the traditional Tergipedidae family is polyphyletic and belongs to a larger monophyletic clade including members of the traditional families Eubranchidae, Fionidae and Calmidae; this was an unexpected result, since the validity of these taxa and their distinctness from the Tergipedidae was never questioned before. They proposed to join the families Tergipedidae, Eubranchidae, Calmidae and Fionidae under the name of Fionidae. This decision has been reinterpreted and completed in the paper by Korshunova et al. (2017) because it obviated evident morphological and molecular aspects.

Synonyms

  • Aeolis exigua (Alder & Hancock, 1848)
  • Eolis exigua Alder & Hancock, 1848 (original)
  • Galvina exigua (Alder & Hancock, 1848)
  • Tergipes fustifer Lovén, 1846

Description
The specific name of this animal refers to its small size, usually not exceeding 6 mm. The body has a whitish colour, somewhat yellowish, which is masked by the numerous greenish spots of varying size that appear in the back and sides of the body and between the bases of the cerata, where they are somewhat darker. These spots can also be located on the back of the head in larger size specimens. The heart area is located on the back, between the second or third group of cerata, depending on the size of the animal. Immediately behind and slightly to the right there is the anal opening. Oral palps are short and have the same colour as the body and may also have some greenish spots. The rhinophores are smooth and semi-transparent and have some white spots, which also often occur between the bases of them. The end of the rhinophores may have a greenish-brown subapical ring. There are usually 6 to 7 groups of cerata in both sides of the back, but usually only the first two groups have more than one cerata, while the rest have just one. Cerata have the ability to contract, acquiring a more or less rounded shape, and to stretch, and then it can be observed having two expansions, a larger volume one in the centre of cerata and a smaller subapical one. The cerata are semitransparent and have greenish spots that sometimes are concentrically aligned; a subapical pale brown ring is also observed. The digestive gland in the cerata is coloured light brown and is usually wider at the greater expansion of the cera. The foot is somewhat broadened in its anterior zone, forming a pair of short, rounded propodial palps.

Biology
E. exiguus is a aeolidacean that usually lives on different species of algae (Codium spp) having hydrozoans colonies as epibionts. Because of its small size and mimicry, individuals of E. exiguus are mostly invisible on the algae. Numerous species of hydroids (Abietinaria abietina, Bougainvillia ramosa, Cordyophora lacustrus, Coryne sp., Eudendrium sp., Halecium halecinum , Hydrallmania falcata, Kirchenpaueria pinnata, several species of Laomedea, Obelia, Plumularia catharina and Tubularia indivisa) have been cited as a substrate for this species, which has also been observed on shells of Mytilus galloprovincialis with epibiontic hydroids of the genus Obelia and on Posidonia oceanica leaves. It is suggested that feeds mainly on polyps of Obelia (Schmekel & Portmann, 1982). The spawn of this small Eubranchus is kidney shaped and measures 1.5 mm. The eggs are white, have a size of about 90 microns, and are tightly placed within the organic matrix of the spawn.

Etymology

  • “Eu” derives from Greek word for “good”, but also “original” or “primitive”. “Branchus” derives from “branchos”, gill.
  • “exiguus” from Latin word for “insignificant”, “insufficient”.

Distribution
This species is distributed throughout all the coasts of Europe, from Norway to the Mediterranean Sea. There are doubtful reports from Greenland and the Atlantic coast of the United States that should be validated. In the Iberian Peninsula it has been observed in the Bay of Biscay, Galicia, Portugal, Straits of Gibraltar and the Catalan coast. In Catalonia it has been reported in Llafranc, Tossa de Mar, Blanes, Sitges and the port of Tarragona.

Known georeferenced records of the species: Eubranchus exiguus
Sources:
: OBIS
: GROC 2010-2011
: Enric Madrenas
: João Pedro Silva
: Bernard Picton
: GBIF.ORG
: OPK
: VIMAR
: Manuel Ballesteros.
: M@re Nostrum
: Altres fonts
: Marine Regions

Similar species
Eubranchus capellinii, with a trapezoidal spot behind the rhinophores.

Abundance

    Western Mediterranean: ★☆☆☆☆
    Eastern Mediterranean: ☆☆☆☆☆
    Atlantic Ocean: ★☆☆☆☆
Month

This chart displays the monthly observation probability for Eubranchus exiguus based on our own records.

More pictures

Bibliography

    Abbott RT. 1954. American seashells. With illus. by Frederick M. Bayer. Van Nostrand. Available from http://www.biodiversitylibrary.org/page/7258062.
    Alder J, Hancock A. 1848. A monograph of the British nudibranchiate Mollusca: with figures of all the species. Ray Society, London.
    Altena CO v. R. 1937. Bijdrage tot de Kennis der Fossiele, Subfossiele en recente Mollusken, die op de Nederlansche Stranden Aanspoelen, en Hunner Verspreiding, xii + 184 pp, 12 pls. D. van Sijn & Zonen, Rotterdam.
    Anderson J. 1999 2014. Eubranchus exiguus accessed through: Scottish Nudibranchs on 2014-12-21. Available from http://www.nudibranch.org/Scottish Nudibranchs/eubranchus-exiguus.html.
    Baba K. 1960. Two new species of the genus Eubranchus from Japan (Nudibranchia - Eolidacea). Publications of the Seto Marine Biological Laboratory 8(2):299-302, pl 34.
    Ballesteros M. 1991. Els Opistobranquis. pp. 416-427. In: Historia Natural dels Països Catalans,  Invertebrats no artròpodes. Enciclopèdia Catalana. Barcelona.
    Ballesteros M. 2007. Lista actualizada de los opistobranquios (Mollusca: Gastropoda: Opisthobranchia) de las costas catalanas. Spira. 2(3):163–188.
    Ballesteros M. 1980. Contribución al conocimientos de los Sacoglosos y Nudibranquios (Mollusca: Opisthobranchia). Estudio anatómico, sistemático y faunístico de las especies del mediterráneo español. Tesis Doctoral. Barcelona: Universitat de Barcelona.
    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, Madrenas E, Pontes M. 2023. OPK - Opistobranquis. Available from https://opistobranquis.info/.
    Ballesteros M, Pontes M, Madrenas E. 2019. Els nudibranquis del mar català. Figueres: Brau Edicions. 192 p.
    Barletta G. 1981. Gasteropodi nudi (Pleurobranchomorpha, Sacoglossa, Aplysiomorpha e Nudibranchia) Consiglio Nazionale delle Richerche, Guide per il riconoscimento delle specie animali delle acque lagunari e costiere italiane AQ/1/92, 3. Quaderni della Civica Stazione Idrobiologica di Milano (9):1-124.
    Bayer FM. 1963. Observations on pelagic mollusks associated with the siphonophores Velella and Physalia. Bull. Mar. Sci. of the Gulf & Caribbean 13(3):454-466.
    Bebbington A, Thompson TE. 1968. Note sur les opisthobranches du Bassin d’Arcachon. Actes de la Societe Linneenne de Bordeaux, ser. A, 105(5):1-35.
    Bedulli D, Cattaneo-Vietti R, Chemello R, et al. 1995. Gastropoda Opisthobranchia, Divasibranchia, Gymnomorpha, Fascicolo 15, pp. 1-23.  In: A. Minelli, A. Ruffo, & S. La Posta (Eds.). Checklist delle specie fauna italiana. Bologna: Calderini (Checklist delle specie della Fauna Italiana).
    Brown GH, Picton BE. 1979. Nudibranchs of the British Isles — a colour guide. Underwater Conservation Society, Manchester, by R. Earll. 30 p.
    Calado G, Urgorri V, Gaspar R, et al. 1999. Catálogo de los moluscos opistobranquios bentónicos de las costas de Setúbal-Espichel (Portugal). Nova Acta Científica Compostelana (Bioloxía) 9: 285-294.
    Capdevila M, Folch J. 2009. Fauna malacològica del Parc Subaquàtic de Tarragona (el Tarragonès, Catalunya, Espanya). SPIRA Vol. 3 Núms. 1-2 Pàg. 33-51.
    Cattaneo-Vietti R. 1986. Alcune considerazioni sui molluschi opistobranchi del Mar Ligure. Lavori Societa Italiana di Malacologia 22:85-96.
    Cattaneo-Vietti R, Barletta G. 1984. Elenco preliminare dei molluschi opistobranchi viventi nel Mediterraneo (Sacoglossa, Pleurobranchomorpha, Acochlidiacea, Aplysiomorpha, Nudibranchia). Bollettino Malacologico (Pubblicazione Mensile Edita dalla Societa Italiana di Malacologia) 20(9-12):195-218.
    Cattaneo-Vietti R, Chemello R. 1991. The opisthobranch fauna of a Mediterranean lagoon (Stagnone di Marsala, western Sicily). Malacologia 32(2):291-299.
    Cattaneo-Vietti R, Thompson TE. 1989. Mediterranean opisthobranch molluscs: a zoogeographic approach. Bollettino Malacologico (Pubblicazione Mensile Edita dalla Societa Italiana di Malacologia) 25(5-8):183-204.
    Cattaneo-Vietti R, Chemello R, Giannuzzi-Savelli R. 1990. Atlas of Mediterranean Nudibranchs. Rome, Italy: La Conchiglia. 264 p.
    Cella K, Carmona L, Ekimova I, et al. 2016. A Radical Solution: The Phylogeny of the Nudibranch Family Fionidae. PLoS ONE 12/2016; 11(12):e0167800. https://doi.org/10.1371/journal.pone.0167800.
    Cervera JL, Templado J, García-Gómez JC, et al. 1988. Catálogo actualizado y comentado de los Opistobranquios (Mollusca, Gastropoda) de la Península Ibérica, Baleares y Canarias, con algunas referencias a Ceuta y la isla de Alborán. Iberus, supl. 1: 1-84.
    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.
    Cornet R, Marchad M. 1951. Inventaire de la faune marine de Roscoff Mollusques. Travaux de la Station Biologique de Roscoff, Suppl 5:1-80.
    De Fez S. 1974. Ascoglosos y Nudibranquios de España y Portugal. Valencia, Spain: Consejo Superior de Investigaciones Científicas. 325 p.
    de Montaudouin X, Sauriau P-G. 2000. Contribution to a synopsis of marine species  richness in the Perthuis Charentais Sea with new insights in soft-bottom macrofauna of the Marennes- Oléron Bay. Cahiers de Biologie Marine 41(2):181-222.
    Debelius H, Kuiter RH. 2007. Nudibranchs of the world. Frankfurt: IKAN- Unterwasserarchiv. 360 pp. p.
    Doneddu M, Manunza B, Trainito E. 1995. Opistobranchi del Nord Sardegna: censimento ed annotazioni. Biologia Marina Mediterranea II (2): 369-370.
    Eales NB. 1967. The littoral fauna of the British Isles: a handbook for collectors, 4th ed; pp i-xviii, 1-297, pls. A-H. University Press, Cambridge, England.
    Edmunds M. 1982. Speciation in chromodorid nudibranchs in Ghana. Proceedings of the 7th International Malacological Congress, August 31-September 7, 1980. Gaillard,-J.M.-ed. 1982. Malacologia 22(1/2):515-522.
    Edmunds M. 1966. Protective mechanisms in the Eolidacea (Mollusca, Nudibranchia). Journal of the Linnean Society (Zoology) 46(308):27-71, pls. 1-4.
    Edmunds M. 1987. Color in opisthobranchs. Western Society of Malacologists Annual Report 19:24.
    Edmunds M. 1987. Color in opisthobranchs. American Malacological Bulletin 5(2):185-196.
    Edmunds M. 1991. Does warning coloration occur in nudibranchs. Malacologia 32(2):241-255.
    Edmunds M, Kress A. 1969. On the european species of Eubranchus (Mollusca: Opisthobranchia). Journal of the Marine Biological Association of the United Kingdom 49: 879-912.
    Evertsen J, Bakken T. 2005. Nudibranch diversity (Heterobranchia, Gastropoda) along the coast of Norway. Fauna Norvegica, 25: 1-37.
    Evertsen J, Bakken T. 2013. Diversity of Norwegian sea slugs (Nudibranchia): new species to Norwegian coastal waters and new data on distribution of rare species. Fauna Norvegica 32: 45-52. https://doi.org/10.5324/fn.v31i0.1576.
    Fernández-Ovies CL. 1981. Contribución a la clasificación morfológica de las puestas de los opistobranquios (Mollusca: Gastropoda). Boletín de Ciencias de la Naturaleza del Instituto de Estudios Asturianos 28: 3-12.
    Furfaro G, Vitale F, Licchelli C, et al. 2020. Two Seas for One Great Diversity: Checklist of the Marine Heterobranchia (Mollusca; Gastropoda) from the Salento Peninsula (South-East Italy). Diversity. 12(12):171.
    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. 1983. Moluscos opistobranquios del Estrecho de Gibraltar y Bahía de Algeciras. Iberus.(3):41–46.
    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. 1983. Moluscos Opistobranquios del Estrecho de Gibraltar y Bahía de Algeciras. Iberus 3: 41-46.
    Giribet G, Peñas A. 1997. Fauna malacológica del litoral del Garraf (NE de la Península Ibérica). Iberus 15 (1): 41-93.
    Hayward PJ, Wigham GD, Yonow N. 1990. Mollusca I: Polyplacophora, Scaphopoda, and Gastropoda; pp. 628-730, In: , The marine fauna of the British Isles and north-west Europe, volume 2, xvi + 996 pp. Oxford University Press.
    Høisæter T. 1986. An annotated check-list of marine molluscs of the Norwegian coast and adjacent waters. Sarsia 71(2):73-175.
    Hunnam P, Brown G. 1975. Sublittoral nudibranch Mollusca (sea slugs) in Pembrokeshire waters. Field Studies 4(2):131-159.

    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) "Eubranchus exiguus" in OPK-Opistobranquis. Published: 16/05/2012. Accessed: 19/03/2024. Available at (https://opistobranquis.info/en/?p=579)

To copy this cite click on the right button.