Onchidoris sparsa

Onchidoris sparsa (Alder & Hancock, 1846)

Onchidoris sparsa by Manuel Ballesteros

Taxonomy
 

Superdomain

Biota  

 

Kingdom

Animalia  

 

Phylum

Mollusca  

 

Class

Gastropoda  

 

Subclass

Heterobranchia  

 

Infraclass

Euthyneura  

 

Subterclass

Ringipleura  

 

Superorder

Nudipleura  

 

Order

Nudibranchia  

 

Suborder

Doridina  

 

Infraorder

Doridoidei  

 

Superfamily

Onchidoridoidea  

 

Family

Onchidorididae  

 

Genus

Knoutsodonta  

 

Species

Knoutsodonta sparsa   (Alder & Hancock, 1846)

 
 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 1259498).
Synonyms

  • Doris sparsa Alder & Hancock, 1846

Description
This is a small species of Onchidoris that does not usually exceed 6 mm in length. The body is very flat and with an oval contour. The coloration is generally yellow, with the center of the dorsum slightly reddish because of the viscera. The mantle margin has small orange-brown spots that contrast with somewhat paler color of the rest of the mantle. When the specimens are observed under binocular microscope a thin black dotting on the mantle becomes apparent, something most clearly visible on the edge of the mantle in ventral view. By transparency the typica spiculation of the dorsum is visible: Transverse spicules in the middle, obliquely laterally and radially arranged around the mantle margin. The dorsum has conical tubercles but with a rounded apex, semitransparent but with an orange-brown tip and a smaller size the closer they are to the mantle margin. The rhinophores are very small, whitish, with few lamellae and some brown spot; there is no rhinophoric sheath but the white gill opening has 2-3 small tubercles like the ones on the dorsum, brown pigmented on the tip. Gill is formed by 5-9 gill leaves depending on the size of the specimen; the unipinnate gill leaves are very small, whitish, forming an incomplete arc around the anus. The foot is white, the reddish-brown digestive gland clearly visible in the center of the foot by transparency. The mouth does not have labial palps.

Biology
This small nudibranch, like others of the same genus, is associated with several species of bryozoans they food on, among which may be mentioned, among others, Cellepora pumicosa, Porella concinna, Celleporina caliciformis (=hassalli) or Schizomavella linearis. Because of its small size, its flattened form, and its peculiar coloration, this is a very cryptic species on the bryozoan colonies on which it is found so it passes almost unnoticed. Little else is known about its biology and reproduction.

Etymology

  • Onchidoris, tuberculate Doris.
  • Doris, a sea nymph in Greek mythology.
  • Sparsa, sparse.

Distribution
There are very few citations of this species, mainly found in the British Isles, Ireland and also in the Iberian Peninsula, where it has been cited in the Cantabrian and Galician coast. First observations in the Mediterranean are credited to Ballesteros (1984) among specimens collected in Tossa de Mar; later on it has also been collected in waters of the Levantine coast.

Known georeferenced records of the species: Onchidoris sparsa
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

Abundance

    Western Mediterranean:
    Eastern Mediterranean:
    Atlantic Ocean:

More pictures


Bibliography

Further reading

Cite this article as:

Ballesteros, Manuel, Enric Madrenas, Miquel Pontes (2012-2018) "Onchidoris sparsa" in OPK-Opistobranquis, Published: 29/08/2012, Accessed: 15/10/2018 at (https://opistobranquis.info/en/N0Mwa)

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