Emarginula conica Lamarck, 1801
Piero Piani (1984) has demonstrated in a publication that there is no reason to prefer the synonym Emarginula reticulata Sowerby, 1813 over the older name Patella fissura Linnaeus, 1758.
The shell of the slit limpet has an elevated conical profile with its apex strongly curved backwards, but never overhanging the posterior margin. The color of the shell is dull white, gray or yellowish. The shell is usually about 10 mm long (but can reach a length of 15 mm), 8 mm high and 6 mm wide. The shell has a reticulate (= net-like) sculpture with 25-35 radial ribs, alternating stronger and weaker, intersecting with spiraled ridges. There is a narrow and deep slit at the anterior margin above the mantle cavity. An exhalent siphon projects thorough this slit. The aperture of the shell occupies the whole undersurface of the shell and lacks an operculum.
The shield-shaped foot is broader anteriorly. It has on each side ten well-developed tentacles at the epipodium (the lateral grooves between foot and mantle). There is an additional tentacle at the right side at the back of the head.
Distribution and habitat
The slit limpet is a common keyhole limpet and can be found along the eastern Atlantic, west European coasts, as far north as Norway and the Faroe Islands and south to the Canary Islands. It is a rare in the western Mediterranean Sea. It thrives on the lower shore and the subtidal zone to a depth of 265 m on rocks and hard substrates where sponges occur.
The slit limpet is carnivorous and feeds on sponges. It is also a herbivorous graze and deposit feeder.
- Linnaeus, C. (1758). Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio decima, reformata. Laurentius Salvius: Holmiae. ii, 824 pp.. World Register of Marine Species, Retrieved 19 April 2010.
- Emarginula fissura (Linnaeus, 1758). Retrieved through: World Register of Marine Species on 19 April 2010.
- Piani, P. (1984). Revisione del genre Emarginula Lamarck, 1801 in Mediterraneo. Lao. Soc. Ital. Malacol. (Milano) 21
- WoRMS : Emerginula fissura
- P.J. Hayward, and J.S. Ryland (1996). Handbook of the Marine Fauna of North-West Europe. Oxford University Press. p. 500. ISBN 0-19-854055-8.
- Gofas, S.; Le Renard, J.; Bouchet, P. (2001). Mollusca, in: Costello, M.J. et al. (Ed.) (2001). European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification. Collection Patrimoines Naturels, 50: pp. 180–213
- Seaward, D.R., 1990. Distribution of the marine molluscs of north west Europe. Nature Conservancy Council.
- Poppe, G.T. & Y. Goto, 1991. European Seashells. Vol. I. 352 pp. Wiesbaden/Verlag Christa Hemmen.