Proctonotus mucroniferus

Proctonotus mucroniferus (Alder & Hancock, 1844)

Proctonotus mucroniferus Loch Torridon, W. Scotland. Photo Gil Green. by Bernard Picton

Taxonomy
 

Superdomain

Biota  

 

Kingdom

Animalia  

 

Phylum

Mollusca  

 

Class

Gastropoda  

 

Subclass

Heterobranchia  

 

Infraclass

Euthyneura  

 

Subterclass

Ringipleura  

 

Superorder

Nudipleura  

 

Order

Nudibranchia  

 

Suborder

Cladobranchia  

 

Superfamily

Proctonotoidea  

 

Family

Proctonotidae  

 

Genus

Proctonotus  

 

Species

Proctonotus mucroniferus  (Alder & Hancock, 1844)

 
 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 140858).
Synonyms

  • Venilia mucronifera Alder & Hancock, 1844
  • Zephyrina pilosa de Quatrefages, 1844

Description
Body up to 15mm long, coloured yellowish brown, marbled and spotted with darker brown. The dorsum is pale yellowish brown, clouded and freckled with darker brown, and sprinkled with minute white dots. Rest of the body hyaline white, nearly transparent, with a few small brown spots on the head and the margin of the foot, mixed with more numerous opaque white dots. The back is depressed and slightly rough, while the sides are smooth and concave. Rhinophores are wrinkled and nodulose. Cerata are ovate or inversely pear shaped, with blunt tips and almost colourless, covered with sparse tubercular white points over the whole surface, and they grow along the projecting sides of the notum in a dozen transverse rows of three papillae each, very close at the base, those next to the back are large and inflated, the exterior ones very small. Two cerata larger than the rest are located in the rear side close to the tail. There are also 4 large elliptical tuberculated cerata passing round the head ahead of the rhinophores. All cerata but those ahead of the rhinophores show a yellowish digestive gland with undulated margins inside. Oral veil is small and strongly notched, covering two cylindrical oral tentacles surrounding the mouth. The foot is deeply grooved and bilobed, the sides rounded, tappering backwards to a fine tail. Prominent anus, located on the rear side of the dorsum.

Biology
Original specimen used for its description was found by a shallow depth dredge at Malahide, Dublin, Ireland, attached to a Halichondria panicea sea sponge. It detaches the larger cerata when stressed, which are quickly replaced with apparently no adverse effects for the animal.

Etymology

  • Proctonotus. From ancient Greek “proktos”, anus and “noton”, dorsum or back, stating that has the anus located dorsally.
  • Mucroniferus. From ancient Latin “mucron”, mucron (a short, more or less sharp and well differentiated tubercle that ends abruptly) and “fero”, to bring, to carry.

Distribution
Eminently an Atlantic and extremely rare species, it has only been reported from Malahide Bay, Ireland (Alder & Hancock, 1844), in Clyde Bay (Thompson & Brown, 1984), in Loch Torridon, Scotland (top photo), in Vikaneset, Kristiansund, Norway (Christian Skauge, 2007 in Sea Slug Forum) and on the French Atlantic coast in Saint Vaast la Hougue (Quatrefages, 1844) and Roscoff (Vayssière, 1913). The report of Fez (1974) in the coasts of Finisterre (Galicia, Spain) is most probably a confusion since it alludes to a report by Vayssière in Roscoff (Finistère, France).

Known georeferenced records of the species: Proctonotus mucroniferus
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

Similar species
Janolus hyalinus, with a sensorial crest between the rhinophores known as “caruncle”, absent in P.mucroniferus.

Abundance

    Western Mediterranean:0 out of 5 stars
    Eastern Mediterranean:0 out of 5 stars
    Atlantic Ocean:1 out of 5 stars
Month

This chart displays the monthly observation probability for Proctonotus mucroniferus based on our own records.

More pictures

Bibliography

Further reading

Cite this article as:

Ballesteros, Manuel, Enric Madrenas, Miquel Pontes (2021) "Proctonotus mucroniferus" in OPK-Opistobranquis. Published: 20/10/2014. Accessed: 04/03/2021. Available at (https://opistobranquis.info/en/NmcR2)

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