Emarginula fissura
Encyclopedia
Emarginula fissura , the common slit limpet, is a species
of sea snail
, a marine gastropod mollusk in the family
Fissurellidae, the keyhole limpets.
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 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.
The larvae have a short planktonic development, non-planktotrophic as usual in Vetigastropoda
and Patellogastropoda
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.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of sea snail
Sea snail
Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....
, a marine gastropod mollusk in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Fissurellidae, the keyhole limpets.
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 .
Description
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 operculumOperculum (gastropod)
The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...
.
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.
The larvae have a short planktonic development, non-planktotrophic as usual in Vetigastropoda
Vetigastropoda
Vetigastropoda is a major taxonomic group of sea snails, marine gastropod mollusks that form a very ancient lineage. Taxonomically Vetigastropoda are sometimes treated as an order although they are a clade in Bouchet and Rocroi, 2005....
and Patellogastropoda
Patellogastropoda
Patellogastropoda, common name true limpets and historically called Docoglossa, is a major phylogenetic group of marine gastropods, seen either as a clade or as a taxonomic order.-Taxonomy:Patellogastropoda was proposed by David R...
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 NorwayNorway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
and the Faroe Islands
Faroe Islands
The Faroe Islands are an island group situated between the Norwegian Sea and the North Atlantic Ocean, approximately halfway between Scotland and Iceland. The Faroe Islands are a self-governing territory within the Kingdom of Denmark, along with Denmark proper and Greenland...
and south to the Canary Islands
Canary Islands
The Canary Islands , also known as the Canaries , is a Spanish archipelago located just off the northwest coast of mainland Africa, 100 km west of the border between Morocco and the Western Sahara. The Canaries are a Spanish autonomous community and an outermost region of the European Union...
. It is a rare in the western Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
. It thrives on the lower shore and the subtidal zone
Neritic zone
The neritic zone, also called coastal waters, the coastal ocean or the sublittoral zone, is the part of the ocean extending from the low tide mark to the edge of the continental shelf, with a relatively shallow depth extending to about 200 meters...
to a depth of 265 m on rocks and hard substrates where sponges occur.