Atalodoris pusilla is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae.MolluscaBase eds. (2025). MolluscaBase. Atalodoris pusilla (Alder & Hancock, 1845). Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=1565333 on 2025-09-10

Description (Original description) The body is ovate and notably depressed. The cloak is a yellowish-white, thickly freckled with dark brown spots, and is covered with numerous conical papillae that are obtusely pointed at the top.

The tentacles are long, slender, pure white, and finely laminated. The branchial plumes, nine in number, are a beautiful white and are simply pinnate. They are arranged in an incomplete, somewhat distant circle around the vent and are retractile within separate cavities.

The head has a broad veil, and the foot is rather broad. Alder J. & Hancock A. (1845). Notice of a new genus and several new species of nudibranchiate Mollusca. Annals and Magazine of Natural History 16: 311-316, page 313.

Distribution This species was described from Tor Bay, Devon, England. It is currently known from the European coasts of the North Atlantic Ocean from Norway, south to the Atlantic coast of Spain.Picton, B.E. & Morrow, C.C. (2015). Onchidoris pusilla (Alder & Hancock, 1845). [In] Encyclopedia of Marine Life of Britain and Ireland. Accessed on 2016-01-18.Thompson, T. E. and G. H. Brown (1984). Biology of Opisthobranch Molluscs Vol 2. 229 pp. 41 Pls. Ray Society, page 60.

This species was also described from Banyuls-sur-Mer on the Mediterranean Sea coast of France. It has been reported from the Bay of Naples, Italy and the Catalan coast of Spain at Cadaqués and some other location in the Costa Brava.Ballesteros, M., E. Madrenas, M. Pontes et al. (2012-2016) Onchidoris albonigra in OPK-Opistobranquis, Published: 29/08/2012, Accessed: 20/01/2016.

Diet Atalodoris pusilla feeds on the bryozoans Escharella immersa, Microporella ciliata, Escharoides coccineus and Porella concinna.

See also

Knoutsodonta

Onchidoris

References

Pruvot-Fol A. (1951). Etudes des nudibranches de la Méditerranée 2. Archives de Zoologie Expérimentale et Générale 88: 1-80.