Atalodoris sparsa is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae.MolluscaBase eds. (2025). MolluscaBase. Atalodoris sparsa (Alder & Hancock, 1846). Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=1565665 on 2025-09-10
Description (Original description) The body is ovate and notably depressed. The cloak is an obscure pale yellow with a few reddish-brown freckles and distant spiculose tubercles.
The dorsal tentacles are slightly conical with eight or nine broad, distant laminae and are blotched with olive-brown. The margins of their cavities have three or four tubercular points.
The gills are very small and colorless, consisting of nine pinnate plumes arranged in a horseshoe shape. The head has a large, semicircular veil. The foot is nearly as broad as the cloak, colorless, and is slightly bilobed at the front. Alder J. & Hancock A. (1846). Notices of some new and rare British species of naked Mollusca. Annals and Magazine of Natural History 18: 289-294, pl. 4.
Distribution This species was described from Cullercoats, North Tyneside, England. It is currently known from the European coasts of the North Atlantic Ocean from Norway, Orkney and Sweden south to the northern coast of Spain.Picton, B.E. & Morrow, C.C. (2015). Onchidoris sparsa (Alder & Hancock, 1846). [In] Encyclopedia of Marine Life of Britain and Ireland. Accessed on 2016-01-15.Rudman, W.B., 2009 (November 29) Onchidoris sparsa (Alder & Hancock, 1846). [In] Sea Slug Forum. Australian Museum, Sydney.Thompson, T. E. and G. H. Brown (1984). Biology of Opisthobranch Molluscs Vol 2. 229 pp. 41 Pls. Ray Society, page 62.Ortea, J. A. (1979). Onchidoris sparsa (Alder & Hancock, 1846) in Asturias, northern Spain. The Veliger 22(1): 45-48.
Diet Atalodoris sparsa feeds on the bryozoan Cellepora pumicosa. It has also been reported to eat Porella concinna.
See also Knoutsodonta
References