Diaphorodoris alba

Diaphorodoris alba Portmann & Sandmeier, 1960

Diaphorodoris alba 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: Onchidoridoidea  J.E. Gray, 1827
Family: Calycidorididae Roginskaya, 1972
Genus: Diaphorodoris  Iredale & O’Donoghue, 1923
Species: Diaphorodoris alba Portmann & Sandmeier, 1960

Taxonomic note: The systematic rank of the nudibranch Diaphorodoris luteocincta has been debated for many decades. Many authors considered the subspecies D. luteocincta var. alba and D. luteocincta var. reticulata variations of the same species, however the recent morphological and molecular analyses performed by Furfaro et al. (2016) clearly deny this conclusion, demostrating that they are two different species: D. alba and D. luteocincta respectively.

Synonyms

  • Diaphorodoris luteocincta var. alba Portmann, 1960

Description
Specimens of this species can reach up to 12 mm in length. The color of the animal is almost transparent white with the mantle bordered by an unbroken yellow band that reaches the edge and the underside of the mantle. On the oval shaped dorsum there are white, well spaced, conical protrusions. The dorsum is covered by spicules forming a clearly visible reticula. The internal viscera can be seen by transparency as a slight dark tonality in the center of the dorsum. In some specimens there could be a reddish pigmentation on the dorsum that can lead to confusion with the very similar species D. luteocincta, but they can differentiated by the yellow strip around the edge of the mantle (Pellet, B.; Manex; Pascual, R.), the higher body and the bigger tail of D.alba. The long rhinophores are transparent at the base and iridescent opaque white in their upper half, have 8-13 lamellae and can be partially retracted; The rhinoforal sheath has 2-3 small conical tubercles on its upper edge. The gill is formed by 3-5 white unipinnate gill leaves, with opaque white on their rachis and tips, surrounding the upper side of the anal papilla; one of the gill leaves, the largest, is directed forward, while the two on the rear side, almost rudimentary, are the smallest. The foot is translucent white and in the anterior side forms two thick lips -oral tentacles- that surround the mouth; on the rear side, the foot is prolonged in a wide sharp tail of triangular section with lateral margins and a white median dorsal line. Two white lines run along the foot margin, converging on the tail tip.

Biology
This nudibranch is frequent wandering on dimly illuminated rocky walls with abundance of scyaphillic algae, hidrozoans, sponges and bryozoans. It feeds on bryozoans such as Smittina reticulata and Cellepora pumicosa (Thompson & Brown, 1984; McDonald & Nybakken, 1996), so the high number of reports for this species on seaweeds would be explained by the presence of epibiont bryozoans on these algae. The spawn is a white ribbon with few eggs (about 120) of very small size (about 70 microns). There are reports of Diaphorodoris alba mating with Diaphorodoris luteocincta or Diaphorodoris papillata in the Mediterranean. Being different species we assume this does not result on viable offspring, as we have never observed hybrid specimens either.

Etymology

  • Diaphorodoris. Diaphanous Doris
  • Doris. In Greek mythology, wife of Nereo, nymph of the waters and mother of Nereids.
  • Alba. From Latin “albus”, white.

Distribution
It is common in both the eastern and western Mediterranean basins and in the coasts of Portugal. It is also present on the European Atlantic coasts, but only up to the southeast of England and Wales, with the northernmost register in Martin’s Haven, Pembrokeshire. In the Iberian coasts it has been reported in the Cantabrian shores, the coasts of Portugal, the Strait of Gibraltar, and in all the Mediterranean coasts. Also mentioned in Balearic Islands, the Canary Islands and the Azores. In the Catalan coasts it is common throughout the rocky coast of the Costa Brava.

Known georeferenced records of the species: Diaphorodoris alba (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:3 Stars
        Atlantic Ocean:1 Stars
This chart displays the observation probability for Diaphorodoris alba
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:

Pontes, Miquel, Manuel Ballesteros, Enric Madrenas et al. (2012-2017) "Diaphorodoris alba" in OPK-Opistobranquis, Published: 18/11/2016, Accessed: 23/05/2017 at (http://opistobranquis.info/en/QnSFb)

In order to copy this cite or text fragments you must be a registered user.