Knoutsodonta sparsa

Knoutsodonta sparsa (Alder & Hancock, 1846)

Knoutsodonta sparsa by Enric Madrenas

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
  • Onchidoris sparsa (Alder & Hancock, 1846)

Description
This is a small species of Knoutsodonta that does not usually exceed 6 mm in length. The body is very flat and with an oval shape. The coloration is generally yellow, with the center of the dorsum slightly reddish because of the internal viscera. The mantle margin has small orange-brown spots that contrast with the somewhat paler color of the rest of the mantle. When the specimens are observed under binocular microscope it becomes apparent that there are thin black dots on the mantle, somewhat more visible on the edge of the mantle in ventral view. Typical dorsum spiculation is visible by transparency: Transverse spicules in the middle, oblique along the sides, 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 white, unipinnate, small gill leaves, forming an incomplete arc around the anus. The foot is white, the reddish-brown digestive gland is 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 feed 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

  • Knoutsodonta, from the Greek meaning “lame tooth”, to represent nudibranch species that lack a rachidian or middle tooth.
  • Sparsa, sparse, referring to the layout of the dorsal tubercles.

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 reported in the Cantabrian and Galician coast. First Mediterranean report was from Tossa de Mar (Ballesteros, 1984), later found in L’Escala. Also reported in Cabo de Palos (Murcia).

Known georeferenced records of the species: Knoutsodonta 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

References for the species: Knoutsodonta sparsa

    Cantabria: Ortea (1979d). Galicia: Ortea (1979d), Fernández-Ovies (1981), Urgorri and Besteiro (1983, 1984). Levante: Templado, Talavera and Murillo (1987). Catalunya: Ballesteros (1984a).

    General: Brown & Picton, 1979:12; Hunnam & Brown, 1975:148; Perrone, 1990b:23; Picton & Morrow, 1994:68[P]; Thompson, 1988:192; Thompson & Brown, 1976:102; 1984:62[P]

    Sources: Cervera et al., 2004, Ballesteros, 2007 & 2016, McDonald, 2006 and other sources.

Similar species
Knoutsodonta neapolitana with similar coloured juveniles (yellowish), but with digitiform tubercles, not conical.

Abundance

    Western Mediterranean:1 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 Knoutsodonta sparsa based on our own records.

More pictures

Bibliography

Further reading

Cite this article as:

Ballesteros, Manuel, Enric Madrenas, Miquel Pontes (2021) "Knoutsodonta sparsa" in OPK-Opistobranquis. Published: 29/08/2012. Accessed: 02/03/2021. Available at (https://opistobranquis.info/en/N0Mwa)

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