Jorunna tomentosa

Jorunna tomentosa (Cuvier, 1804)

Jorunna tomentosa by Enric Madrenas
Taxonomy
Class: Gastropoda  Cuvier, 1797
Subclass: Heterobranchia  J.E. Gray, 1840
Clade: Euthyneura  Spengel, 1881
Clade: Nudipleura  Wägele & Willan, 2000
Order: Nudibranchia  Cuvier, 1817
Suborder: Euctenidiacea  Tardy, 1970
Infraorder: Doridacea  Thiele, 1931
Superfamily: Doridoidea  Rafinesque, 1815
Family: Discodorididae  Bergh, 1891
Genus: Jorunna  Bergh, 1876
Species: Jorunna tomentosa (Cuvier, 1804) [Doris]

Synonyms

  • Doris johnstoni Alder & Hancock, 1845
  • Doris obvelata Johnston, 1838
  • Doris philippii Weinkauff, 1873
  • Doris tomentosa Cuvier, 1804 (original)
  • Jorunna johnstoni (Alder & Hancock, 1845)

Description
This species of doridacean can reach quite appreciable sizes, up to 55 mm in length, but they are normally smaller, at least in the Mediterranean, as average specimens measure between 25 and 35 mm. The usual colour of the body is a more or less light grayish brown, yellow or pale orange and there are often dark spots that appear to form two lines on both sides of the back. The dorsum has numerous small caryophylid tubercles, barely visible to the naked eye, that give the animal a velvety appearance. The caryophylic cone type tubercles are set very tightly and have 6-7 spikes protruding from its surface. A binocular microscope allows to see many small white creamy granulations on the edge of the mantle, more visible on the underside. The rhinophores are small, coloured in a somewhat lighter shade than the body and have about 12 lamellae. The rhinophoric sheath is slightly raised and its upper edge has tubercles similar to those on the back. The gill has 10 to 12 tripinnate gill leaves of the same color of the body and they remain high and tight together even when the animal is relaxed. The anal papilla is brown and closes the circle of gill leaves from behind. The foot is grooved and split ahead and protrudes slightly from behind the mantle when the animal is moving. The mouth has a pair of finger-like oral palps. The mantle is very broad and its underside reveals a grid of spikes that appear to converge towards the dorsal tubercles as well as radially arranged spicules.

Biology
This species usually lives under stones from very shallow depths. It has been reported that it feeds on sponges like Haliclona oculata and H. cinerea, Halichondria panicea, Hemimycale columela and Hymeniacidon sanguinea (McDonald, 2009). The spawn is formed by a slightly elevated ribbon wound in a tight spiral of 2-3 turns, and the eggs are coloured creamy.

Etymology

  • Jorunna. Possibly dedicated to Jorunn Bjarnadottir, a character of an Icelandic viking saga, wife of Ólafr Höskuldsson (c. 938–1006) nicknamed “the Peacock” because of his proud bearing and magnificent wardrobe.
  • Tomentosa. From Latin “tomentum”, means “velvety”, like the stuffing of a pillow or mattress, batt.

Distribution
This is a species that is distributed across all European coasts, from the British Isles, the Netherlands, the French Atlantic coast, the Iberian Peninsula, Canary islands, Azores and the Mediterranean. In the Iberian Peninsula it has been reported in all coastal areas, both Atlantic and Mediterranean (Cervera et al. 2004). In the Catalan coast it has been found in Es Caials (Cadaqués), the Medes islands, Blanes and Cubelles.

Known georeferenced records of the species: Jorunna tomentosa (z-200).
Sources:
: OBIS : OPK
: GROC 2010-2011 : VIMAR
: Enric Madrenas : Manuel Ballesteros.
: João Pedro Silva : M@re Nostrum
: Bernard Picton : Other sources
: GBIF.ORG : Marine Regions

Abundance

        Western Mediterranean:1 Stars
        Eastern Mediterranean:0.0 Stars
        Atlantic Ocean:0.0 Stars
This chart displays the observation probability for Jorunna tomentosa
based on our own records.

More pictures

Bibliography

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, Manuel, Enric Madrenas, Miquel Pontes et al. (2012-2017) "Jorunna tomentosa" in OPK-Opistobranquis, Published: 16/05/2012, Accessed: 27/04/2017 at (http://opistobranquis.info/en/0Gdoy)

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