Learchis poica

Learchis poica  Ev. Marcus & Er. Marcus, 1960

Learchis poica @ Lake Worth Lagoon, Florida, USA by Sandra Edwards

Taxonomy
 

Superdomain

Biota  

 

Kingdom

Animalia  

 

Phylum

Mollusca  

 

Class

Gastropoda  

 

Subclass

Heterobranchia  

 

Infraclass

Euthyneura  

 

Subterclass

Ringipleura  

 

Superorder

Nudipleura  

 

Order

Nudibranchia  

 

Suborder

Cladobranchia  

 

Superfamily

Aeolidioidea  

 

Family

Facelinidae  

 

Genus

Learchis  

 

Species

Learchis poica  Ev. Marcus & Er. Marcus, 1960

 
 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 420632).
Description
Small nudibranch up to 14mm in length. Quite variable in color, the typical pattern is the translucent body with white patching on the head and behind the rhinophores that may form a broad continuous median dorsal band from the front of the head to the tip of the tail. There can also be an opaque white irregular band along each side of the body, below the cerata. It has orange markings on the head, often consisting of an orange line from the base of the oral tentacles to the base of the rhinophores. There can also be an orange patch on each side of the head (cheek patch) that could be replaced by an orange line from the base of the rhinophores to the foot, or from below the rhinophores forward to the front of the head below the oral tentacles. The rhinophores are often described as annulate, perfoliate or lamellate, but they consistently have an irregular arrangement of 6-10 rings or annulations, some of which are irregular or incomplete (Edmunds, 1964). The oral tentacles are smooth. The cerata stand in about 8 groups laid in arches, the hindmost of which are indistinctly separated; they are translucent with a few scattered white patches (covering most of the cerata in certain specimens), a subterminal white band (there could be an orange band in certain specimens) and a white cnidosac on the tip. The digestive gland can be seen, by transparency, inside the cerata and it could be colored from light brown to dark brown or even black. The eyes are black. The foot is narrower than the body, specially in the anterior side, it has a bilabiate anterior border with tappered propodial tentacles normally facing backwards as the animal moves. The tail is short.

Biology
The animals appear to move little. Sometimes it forms clusters on the hydroids they feed on (Halocordyle disticha in the Canary Islands). It has the ability to retain undischarged nematocysts from their preys and store them in the cnidosacs at the tips of cerata. The spawn is a convoluted spiral of white eggs laid on the hydroids they feed on.

Etymology

  • Learchis, of uncertain meaning, seems related to the Greek mythology, where there’s a story about Ino (a mortal queen of Thebes) and Athamas (a Boeotian king, son of Aeolus and Enarete) who hunted his own son Learchos as a stag and slew him. Classical authors like Bergh rarely explained the origins of the names they proposed, but they used to inspire in the Greek and Roman mythology.
  • Poica. No information available about the origin of the specific name.

Distribution
The present species is the first Atlantic member of the genus, and it has been found in Aruba, Bahamas, Barbados, Cayman Islands, Costa Rica, Curaçao, Grenada, Jamaica, Martinique, Mexico, Puerto Rico, St. Lucia, St. Vincent & the Grenadines, Virgin Islands, USA and Venezuela. Also in Ghana, West Africa (Edmunds, 1968), Madeira (Cervera & Malaquias, unpubl. data), Azores (Moro, pers.comm.) and the Canary Islands (Moro, Bacallado y Ortea, 2010).

Known georeferenced records of the species: Learchis poica
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

Abundance

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

This chart displays the monthly observation probability for Learchis poica based on our own records.

More pictures

Bibliography

    Abbott RT. 1974. American seashells. The marine mollusca of the Atlantic and Pacific coast of North America. Van Nostrand, New York. 663 pp., 24 pls. [October 1974].
    Baba K, Hamatani I. 1977. A new species tentatively referred to Antonietta, Antonietta janthina, from Japan (Nudibranchia: Eolidoidea: Facelinidae). Veliger 20(1):9-13.
    Ballesteros M, Madrenas E, Pontes M. 2023. OPK - Opistobranquis. Available from https://opistobranquis.info/.
    Caballer M, Ortea J, Rivero N, et al. 2015. The opisthobranch gastropods (Mollusca: Heterobranchia) from Venezuela: an annotated and illustrated inventory of species. Zootaxa 4034 (2): 201–256.
    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.
    Edmunds M. 1968. Eolid Mollusca from Ghana, with further details of west Atlantic species. Bulletin of Marine Science 18(1):203-219.
    Edmunds M. 1970. Opisthobranchiate Mollusca from Tanzania. II. Eolidacea (Cuthonidae, Piseinotecidae and Facelinidae). Proceedings of the Malacological Society of London 39(1):15-57; tbls. 1-3; figs. 1-24.
    Edmunds M. 2015. Opisthobranchiate Mollusca from Ghana, Aeolidiidae, with consideration of several caribbean species. Journal of Conchology Vol. 42(2): 125-161.
    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. 1977. Larval development, oceanic currents, and origins of the Opisthobranch fauna of Ghana. Journal of Molluscan studies 43:301-308.
    Edmunds M. 1964. Eolid Mollusca from Jamaica, with the description of two new genera and three new species. Bulletin of Marine Science of the Gulf and Caribbean 14 (1): 1-32.
    Edmunds M, Just H. 1983. Eolid nudibranchiate mollusca from Barbados. Journal of Molluscan Studies 49 (3): 185-203.
    Frank, B. et al. 1998 2014. Learchis poica accessed through: JaxShells.org on 2014-12-14. Available from http://www.jaxshells.org/poica.htm.
    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.
    Long SJ. 2006. Bibliography of Opisthobranchia 1554-2000. Bayside Books & Press, Tustin, CA, U.S.A. 672p.
    Marcus E d. BR. 1977. An annotated checklist of the western Atlantic warm water opisthobranchs. J. Molluscan Stud., Suppl 4:1-23.
    Marcus E d. BR, Marcus EG. 1963. Opisthobranchs from the Lesser Antilles. Studies on the Fauna of Curacao and other Caribbean Islands 19(79):1-76.
    Marcus Er., Marcus Ev. 1960. Opisthobranchs from American Atlantic warm waters. Bull. Mar. Sci. 10(2):129-203.
    Marcus Er., Marcus Ev. 1970. Opisthobranchs from Curaçao and faunistically related regions. Studies on the fauna of Curaçao and other Caribbean Islands. 33(122):1–129.
    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.
    Moro L, Bacallado JJ, Ortea JA. 2010. Babosas marinas de las islas Canarias. Actas VI Semana Científica Telesforo Bravo, Instituto de Estudios Hispánicos de Canarias. https://doi.org/10.13140/RG.2.1.1168.2009.
    Moro L, Ortea J, Bacallado JJ. 2016. Nuevas citas y nuevos datos anatómicos de las babosas marinas (Mollusca: Heterobranchia) de las islas Canarias y su entorno. Revista de la Academia Canaria de las Ciencias., 48: 9-52.
    Ortea J, Moro L. 2018. Nuevas citas y nuevos datos sobre las lesmas do mar (Mollusca: Gastropoda) de las islas de Cabo Verde (II). Avicennia. 22:49–58.
    Ortea J, Caballer M, Moro L. 2004. Dos aeolidaceos con ceratas rojos de la region macaronesica y el mar Caribe (Mollusca: Nudibranchia). Vieraea 32: 83-96.
    Picton BE. 1979. Caloria elegans, (Alder & Hancock) comb. nov Gastropoda, Opisthobranchia, an interesting rediscovery from S W. England. J. Molluscan Stud. 45(1):125-130.
    Redfern C. 2001. Bahamian seashells: A thousand species from Abaco, Bahamas. Bahamianseashells.com, Inc.
    Rosenberg G. 2009. Malacolog 4.1.1. A Database of Western Atlantic Marine Mollusca. The Academy of Natural Sciences, Philadelphia, PA. Available from http://www.malacolog.org/.
    Rosenberg G, Moretzsohn F, García EF. 2009. Gastropoda (Mollusca) of the Gulf of Mexico, Pp. 579–699 in Felder, D.L. and D.K. Camp (eds.), Gulf of Mexico–Origins, Waters, and Biota. Biodiversity. Texas A&M Press, College Station, Texas.
    Rudman W.B. et al. 1998 2010. Learchis poica accessed through: Sea Slug Forum on 2014-12-14. Available from http://seaslugforum.net/showall/learpoic.
    Shoemaker AH, Porter HJ, Boothe B, et al. 1978. Marine mollusks; pp. 123-135, In: An annotated checklist of the biota of the coastal zone of South Carolina, 364 pp. University of South Carolina Press.
    Templado J, Luque AA, Ortea JA. 1991. A commented check-list of the amphiatlantic Ascoglossa and Nudibranchia (Mollusca: Opisthobranchia). Lavori della Societa Italiana di Malacologia 23:295-326.
    Thompson TE. 1980. Jamaican opisthobranch molluscs II. J. Molluscan Stud. 46(1):74-99.
    Thompson TE. 1977. Jamaican Opisthobranch Molluscs I. Journal of Molluscan Studies 43: 93-140.
    Turgeon D, Quinn JF, Bogan AE, et al. 1998. Common and scientific names of aquatic invertebrates from the United States and Canada: mollusks. 2nd ed. American Fisheries Society Special Publication, 26.
    Valdés A, Hamann J, Behrens DW, et al. 2006. Caribbean sea slugs: a field guide to the opisthobranch mollusks from the tropical northwestern Atlantic. Washington: Sea Challengers Natural History Books. 289 pp.
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    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:

Pontes, Miquel, Manuel Ballesteros, Enric Madrenas (2023) "Learchis poica" in OPK-Opistobranquis. Published: 27/10/2016. Accessed: 19/03/2024. Available at (https://opistobranquis.info/en/?p=22612)

To copy this cite click on the right button.

Acknowledgments
Many thanks to Sandra Edwards, Judy Townsend, Lureen Ferretti and specially to Anne DuPont by putting us in contact with her diving buddies who provided us the Florida pictures of Learchis poica illustrating the record of this species. Thank you very much as well to Susan and Rick Coleman by the Bonaire pictures of Learchis poica, that show a chromatic variation not present in Florida.