Okenia elegans

Okenia elegans (Leuckart, 1828)

Okenia elegans 28mm @ Kašuni, Split (First cite for Croatia) 4-03-2016 7m by Jakov Prkić

Taxonomy
 

Superdomain

Biota  

 

Kingdom

Animalia  

 

Phylum

Mollusca  

 

Class

Gastropoda  

 

Subclass

Heterobranchia  

 

Infraclass

Euthyneura  

 

Subterclass

Ringipleura  

 

Superorder

Nudipleura  

 

Order

Nudibranchia  

 

Suborder

Doridina  

 

Infraorder

Doridoidei  

 

Superfamily

Onchidoridoidea  

 

Family

Goniodorididae  

 

Genus

Okenia  

 

Species

Okenia elegans  (Leuckart, 1828)

 
 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 140037).
Synonyms

  • Euplocamus laciniosus Philippi, 1841
  • Idalia cirrigera Philippi, 1844
  • Idalia dautzenbergi Vayssière, 1919
  • Idalia elegans Leuckart, 1828 (original)

Description
The specimens of this species can reach a maximum size of 80 mm. The body is tall and its general color varies from pure white to white, sprayed with pink or orange-red dots. In all these cases the edge of the foot has a more or less marked yellow band. The most characteristic trait of this species are the digitiform papillae that surround the whole body from the front of the head, the sides of the dorsum and surround the gill leaves. The two most anterior papillae on the head are the longest. There are also papillae in the dorsum middle line. The color of these papillae is like the body at their base, whitish or reddish, but soon they turn yellow but on the apex that is usually whitish. The rhinophores are thick and in the white specimens are semitransparent in their base, white opaque in their middle third and red in their tip while in the most pigmented ones they are orange-red. There are up to twenty fine lamellae in each rhinophore. The gill is made up of 12-14 bipinnate gill leaves that form a complete circle surrounding the anal papilla; The gill leaves are white but their tips are pigmented from yellow to orange, depending on the color of the specimen. The anal papilla is not prominent, it is white with its upper border coloured in yellow or orange. The foot is very wide, slightly bilobed in the front side and pointed in the rear side. It is white coloured but it is finely dotted of pink or red in the most pigmented animals, as are the flanks of these specimens.

Biology
This species is usually found wandering in rocky bottoms where the individual or colonial ascidians of which it feeds on live. The following tunicated have been cited as prey for O.elegans: Ascidia sp., Ciona sp., Molgula sp., Microcosmus sp, Phallusia sp., Polycarpa rustica, P. scuba, Botryllus sp. and Dendrodoa grosularia (Picton & Morrow, 1994; McDonald & Nybakken, 1999). Frequently the specimens of O. elegans are almost completely buried in the body of the ascidian, from which only the gill leaves protrude.

Etymology

  • Okenia. In honor of Prof. Dr. Ludwig Gilbert Lorenz Oken, (1779-1851), German natural philosopher, editor of the magazine “Isis” and publisher of the book “Lehrbuch der Naturgeschichte”.
  • Elegans. From Latin “elegans”, delicious, reloaded, prodigious.

Distribution
This species has been reported from Norway, the British Isles (Picton & Morrow, 2016), the Bay of Biscay, the Iberian Peninsula (Strait of Gibraltar and Catalonia, Cervera et al. 2004) and the Mediterranean Sea (both in the Adriatic and Greek coasts). In the Catalan coasts it has only been observed in Cala Aiguablava (Begur) and in Blanes (both at Punta de Santa Anna and in the trawling location known as La Planassa).

Known georeferenced records of the species: Okenia elegans
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

References for the species: Okenia elegans

    Gibraltar: Sánchez-Santos (unpubl. data). Catalunya: Domènech et al. (2006), Ballesteros (datos no publicados) [Blanes].

    General: Alder & Hancock, 1854:103; 1855:fam. 1, pl. 27[P]; Bergh, 1881c:146; Hoffmann, 1926:15; ICZN, 1974:13; Jeffreys, 1869:78; Lemche, 1972:196; Vayssiere, 1901a:78; 1913a:354; 1919:78 as Idalia elegans; Barletta, 1981:48[P]; Brown & Picton, 1979:9; Hayward, Wigham, & Yonow, 1990:715; Hunnam & Brown, 1975:150; McMillan, 1968:69; Nordsieck, 1972:52; Picton & Morrow, 1994:56[P]; Pruvot-Fol, 1954b:308; Riedl, 1983:333; Schmekel & Portmann, 1982:125; Thompson, 1976:[P]; 1976a:[P]; 1988:162[P]; Thompson & Brown, 1976:82[P]; 1984:43[P]; Vicente, 1967:154 as Okenia elegans

    Sources: Cervera et al., 2004, Ballesteros, 2007 & 2016, McDonald, 2006 and other sources.

Abundance

    Western Mediterranean:
    Eastern Mediterranean:
    Atlantic Ocean:

More pictures

Bibliography

Further reading

Cite this article as:

Ballesteros, Manuel, Enric Madrenas, Miquel Pontes (2012-2018) "Okenia elegans" in OPK-Opistobranquis, Published: 11/09/2014, Accessed: 24/06/2018 at (https://opistobranquis.info/en/0w1tC)

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