Hancockia uncinata

Hancockia uncinata (Hesse, 1872)

Hancockia uncinata 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: Dexiarchia  Schrödl, Wägele & Willan, 2001
Infraorder: Cladobranchia Willan and Morton, 1984
Parvorder: Dendronotida Odhner, 1934
Superfamily: Tritonioidea  Lamarck, 1809
Family: Hancockiidae  MacFarland, 1923
Genus: Hancockia  Gosse, 1877
Species: Hancockia uncinata (Hesse, 1872) [Doto]

Synonyms

  • Doto uncinata Hesse, 1872 (original)
  • Govia rubra Trinchese, 1885
  • Hancockia eudactylota Gosse, 1877

Description
This dendronotacean can reach up to 10 mm in length. The body is narrow and the overall coloration can be pink or pale green depending on the substrate where the animal is found. There are usually white spots formed by small groups of white dots, the size of these spots can be quite variable and they can almost completely cover the back of the animal. These white spots may also form a nearly continuous line on each side of the body crossing the base of lateral appendages. In the head, the cephalic veil has two lobes possessing each one about 2-4 short and round tipped appendages. The rhinophores have a high sheath, trumpet shaped, and whose top edge could be toothed or lobed, that could also be decorated with white spots. The end of the rhinophore is shaped like a club and some oblique lamellae could be observed below. The tip of the rhinophore could be also pigmented white. On both sides of the body there are four lateral appendages (some authors call them cerata, as in aeolidacean nudibranchs) with a very peculiar shape: auriculate or like a fist, open at its outer side or bottom side, and several (up to 7) short digitiform appendices. Of these 4 pairs of lateral appendages, only the first pair in both sides are symmetrical, on the other pairs the appendix located at the left is somewhat more advanced than the one on the right. The foot is narrow.

Biology
This is a highly variable color species, a trait that could correspond to an adaptation to blend with different substrates (red or brown algae) on which it can be found in the search for food. Apparently feeds on hydroids of the species Clytia hemisphaerica, from which it may draw the functional nematocysts of its prey and, according to some authors, keep them in small bumps of the back, sides and rhinophoric sheath appendages, similar to what happens in eolidacean nudibranchs (kleptoplasty). The spawn is a wide scalloped ribbon, similar to that of Doto, and white eggs.

Etymology

  • Hancockia. Dedicated to Albany Hancock (1806-1873), research fellow of Joshua Adler.
  • Uncinata. From latin word for hooked.

Distribution
This species is distributed from the coasts of Northern Ireland, the British Isles, off the French coasts in the Bay of Biscay, the Iberian Peninsula and the western Mediterranean. In the Iberian Peninsula has been cited in all coastal areas including Portugal, also cited in the Balearic and Canary Islands. In Catalonia it has been observed sporadically in several places on the Costa Brava as Tossa de Mar, L’Escala, L’Estartit or El Port de la Selva, among others.

Known georeferenced records of the species: Hancockia uncinata (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:2 Stars
        Eastern Mediterranean:0.0 Stars
        Atlantic Ocean:0.0 Stars
This chart displays the observation probability for Hancockia uncinata
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) "Hancockia uncinata" in OPK-Opistobranquis, Published: 17/05/2012, Accessed: 28/03/2017 at (http://opistobranquis.info/en/oJVbJ)

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