Pleurobranchaea meckeli

Pleurobranchaea meckeli (de Blainville, 1825)

Pleurobranchaea meckeli by Enric Madrenas
Taxonomy
Class: Gastropoda  Cuvier, 1797
Subclass: Heterobranchia  J.E. Gray, 1840
Clade: Euthyneura  Spengel, 1881
Clade: Nudipleura  Wägele & Willan, 2000
Subclade: Pleurobranchomorpha  Schmekel, 1985
Superfamily: Pleurobranchoidea  J.E. Gray, 1827
Family: Pleurobranchaeidae Pilsbry, 1896
Genus: Pleurobranchaea  Meckel in Leue, 1813
Species: Pleurobranchaea meckeli (de Blainville 1825) [Pleurobranchidium]

Synonyms

  • Pleurobranchaea chiajei Locard, 1886
  • Pleurobranchaea dellechiaii Vérany, 1846
  • Pleurobranchaea notmec Ev. Marcus & Gosliner, 1984
  • Pleurobranchaea vayssierei Ev. Marcus & Gosliner, 1984
  • Pleurobranchidium meckeli Blainville, 1825 (original)

Description
The body is high, quite curved, of variable color (ranging from light gray to dark gray, going through all shades of brown and yellow) and reaches a length of about 10 cm, with a mantle that protects the vital organs and is rounded in its rear part, whereas in its front side it forms a big frontal veil that is delimited laterally by two conical tentacles rolled on themselves. The anterior edge of the mantle has sensory digitations. Unlike the other pleurobrancomorphs, this species lacks an inner shell. On both sides of the head are the two rhinophores of cylinder-conical form, rolled on themselves, somewhat similar to the tentacles on the corners of the cephalic veil. The eyes, almost invisible to a diver because they are placed at the level of the abdominal cavity, can be seen by transparency on the rhinophores. The gill is clearly visible on the right side of the body, as it almost protrudes from the edge of the mantle cavity. The gill is bipinnate, coloured beige, and takes approximately one-third of the total length of the animal. The foot, somewhat lighter in color than the body, protrudes from the sides and back of the mantle, where it has a vertical tappered tissue projection. The sole of the foot is smooth. Between the foot and the mantle there is a dark groove with a large number of small lumps or irregular tubercles lighter in color, almost white on the foot, capable of emitting a whitish acidic substance for defensive purposes. In the anterior part of the foot, hidden beneath the frontal veil, there is a short and wide protractile tube, the buccal organ (proboscid), which is evaginable.

Biology
This species uses its sensory papillae, located around the mouth and facial veil to detect its food. It appears to feed on anthozoans (including sea plumes) and hydrozoans, since large numbers of cnidocysts have been found in the stomach of the studied specimens. Cattaneo-Vietti et al. (1993) suggest that it can feed on other living invertebrates, such as the sponge (Thenea muricata), wandering polychaete, amphipods (Caprella sp.) as well as other opisthobranchs (Tethys fimbria, Philine aperta, Facelina sp.). The same study also indicates that small cephalopods (both complete and parts of the body: teeth, traces of eyes …) were found in the digestive system of the examined specimens, along with fish scales and spines. He probably captures both live and dead animals and, under certain conditions (aquarium), it is known to feed on other specimens of its own species (Pruvot-Fol, 1954). It is considered a ravenous opportunist predator. Reproduction takes place in autumn. The spawn is a fairly wide ribbon, fixed to the substrate, and arranged in tight undulations, with white eggs. It is not uncommon for the animal to carry some sand on the body as it moves, as it helps to camouflage itself. Robert Dollfus (in Pruvot-Fol, 1954) indicates that the body of this species may be parasitized by the copepod Anthessius pleurobrancheae Delle Valle, 1880.

Etymology

  • Pleurobranchaea. From greek “pleura”, to the side of + “bragchia”, gill. Side gill.
  • Meckeli. Dedicated to Dr. Johann Friedrich Meckel, (1781-1833), from Halle, Germany, who worked with Cuvier in Paris. He was known for his wide knowledge of general animal anatomy, but he worked mainly on vertebrates.

Distribution
It is found throughout the Mediterranean, both in the western basin (Spain, France, Italy, …) and in the eastern basin (Turkey, Croatia, …). It has been reported in the Red Sea (Parenzan, 1961 in Barash & Danin, 1971). In the eastern Atlantic is present between the Northern coast of Spain (Avila, 1993) and the Gulf of Guinea (Marcus & Gosliner, 1984), including the Canary Islands (Odhner, 1931), Cape Verde (Vayssière, 1902), Madeira (Wirtz , unpublished data) and Azores (Bergh, 1899). On the Iberian coasts it has been cited in Cantabria (Avila, 1993), Portugal (Nordsieck, 1972), Western Andalusia (Cervera & García Gómez, 1988) and Eastern Andalusia (Luque, 1983), Murcia (Templado et al. 1983), the Balearic islands (Vayssière, 1885) and Catalonia (Ros, 1975). In the Catalan coasts it has been reported in the soft bottoms and detrital substrates of the Barcelona coast (Ballesteros, unpublished data), in Blanes (Ros, 1975) and L’Escala (Weitzmann, 2017, pers. comm.).

Known georeferenced records of the species: Pleurobranchaea meckeli (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:3. Stars
        Eastern Mediterranean:2. Stars
        Atlantic Ocean:2 Stars
This chart displays the observation probability for Pleurobranchaea meckeli
based on our own records.

Video

Pleurobranchaea meckeli @ Sipieres (L’Escala, Spain) 7-07-2017 by Boris Weitzmann

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) "Pleurobranchaea meckeli" in OPK-Opistobranquis, Published: 15/05/2012, Accessed: 17/10/2017 at (http://opistobranquis.info/en/li077)

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