Knoutsodonta sparsa (Alder & Hancock, 1846)
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 | Atalodoris | |
Species | Atalodoris sparsa (Alder & Hancock, 1846) | |
| Classification according to Bouchet et al. (2017) Taxonomic source: World Register of Marine Species (AphiaID: 1565665). | ||
- 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).
| 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
Knoutsodonta neapolitana with similar coloured juveniles (yellowish), but with digitiform tubercles, not conical.
Abundance
| Western Mediterranean: | ★☆☆☆☆ |
| Eastern Mediterranean: | ☆☆☆☆☆ |
| Atlantic Ocean: | ★☆☆☆☆ |
More pictures
Bibliography
Further reading
- Biodiversity Heritage Library
- Encyclopedia of Marine Life of Britain and Ireland
- European Sea Slugs by Morddyn
- Flickr pictures
- Ian Smith account at Flickr
- Interim Register of Marine and Nonmarine Genera
- NCBI GenBank
- OBIS - Search by Taxon
- Sea Slug Forum
- The Conchological Society of Great Britain and Ireland
- World Register of Marine Species
Cite this article as:
Ballesteros, M., Madrenas, E. & Pontes, M. (2012-2025) "Knoutsodonta sparsa" in OPK-Opistobranquis. Published: 29/08/2012. Accessed: 03/02/2025. Available at (https://opistobranquis.info/en/?p=2261)
