Fissurellidae,

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often con ...

the keyhole limpets and slit limpets, is a taxonomic family of small to medium-sized limpet-like

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

s, marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

s in the clade Vetigastropoda.Rosenberg, G. (2012). Fissurellidae. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=111 on 2013-01-02 Their common name derives from the small hole in the apex of their cone-like shells. Although superficially resembling "true" limpets, they are in fact not closely related to them.

Distribution

The distribution of fissurellids is worldwide, from cold waters to tropical waters. Powell A. W. B., ''New Zealand Mollusca'', William Collins Publishers Ltd, Auckland, New Zealand 1979

Habitat

Fissurellids live in habitats on and under rocks in the lower intertidal zones to deeper waters.

Shell description

Keyhole limpets somewhat resemble true limpets because of the simple conical shape of their shells, but in reality they are not closely related to true limpets, which are in the

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

Patellogastropoda. This conical shape and the low profile of the shell allow keyhole limpets to withstand wave attack on exposed rocks to which they attach firmly with their strong, muscular foot. The shell may vary in color and pattern. The shell has a reticulate (= net-like) structure with strong radial ribs and lacks an operculum. The shell ranges from 3 mm to 13.2 cm. The great keyhole limpet ''( Megathura crenulata'') measures up to 13.2 cm. For respiration, the shells of fissurellids have a single apical or subapical perforation ("keyhole"). This opening at the top allows a direct exit of exhalant water currents together with waste products from the mantle cavity. The water enters under the edge of the shell near the head and passes over large paired gills. Most young species in this family have a marginal slit in the middle of the anterior end of the spiral shell. Some species possess just a short internal groove at the anterior end. The paired organs in the mantle cavity represent a primitive condition in gastropods. The soft body consists of a well-developed head, a short muzzle. It has a broad and flat foot and a well-developed mantle. This foot exerts a strong suction, adhering the keyhole limpet to its hard substratum. The mantle extends in some species partly or completely (as in ''Megathura crenulata'') over the shell. The tentacles at the ''epipodium'' (the lateral grooves between foot and mantle) are well developed. The species in '' Medusafissurella'' have numerous subequal tentacles at the propodium, while the species in '' Dendrofissurella'' have an outgrowth with main trunk and side branches at the propodium. The eyes are situated on rudimentary pedicels at their outer bases. The sides are ornamented with short cirri. There are two, symmetrical branchial plumes . The anal siphon occupies the anterior notch or perforated summit of the shell. In addition to the possession of this hole, slit or groove, keyhole limpets differ in several other ways both internally and externally from true limpets.

Feeding habits

Keyhole limpets are in essence herbivorous, feeding primarily on algae, but are also detritus feeders. They play an important role in marine ecosystems by controlling the growth of algae on rocky substrates. A few species in the genera ''Diodora'' and '' Emarginella'' are carnivorous, feeding on sponges. ''Puncturella'' has been reported to digest

diatom A diatom (Neo-Latin ''diatoma'') is any member of a large group comprising several Genus, genera of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a significant portion of Earth's B ...

s and detritus. ''Puncturella aethiopica'' feeds mainly on Foraminifera. They are also prey for various marine animals, including

starfish Starfish or sea stars are Star polygon, star-shaped echinoderms belonging to the class (biology), class Asteroidea (). Common usage frequently finds these names being also applied to brittle star, ophiuroids, which are correctly referred to ...

and some mollusk-eating birds.

Taxonomy

Family Fissurellidae Fleming, 1822 *Subfamily Diodorinae Odhner, 1932 *Subfamily Emarginulinae Children, 1834 *Subfamily Fissurellinae Fleming, 1822 *Subfamily Hemitominae Kuroda, Habe & Oyama, 1971: synonym of Zeidorinae Naef, 1913 *Subfamily Zeidorinae Naef, 1913 This classification was based by Bouchet & Rocroi on the studies by Keen (in Moore) (1960), Christiaens (1973) and McMean (1984). Aktipis S.W., Boehm E. & Giribet G. (2011) then raised the tribe Diodorini to the status of subfamily Diodorinae.

Genera

Genera within the family Fissurellidae include: * '' Agariste'' Monterosato, 1892 * '' Altrix'' Palmer, 1942 * '' Amblychilepas'' Pilsbry, 1890 * '' Buchanania'' Lesson, 1830 * '' Clathrosepta'' McLean & Geiger, 1998 * '' Clypidina'' Gray, 1847 * '' Cornisepta'' McLean & Geiger, 1998 * '' Cosmetalepas'' Iredale, 1924 * '' Cranopsis'' Adams, 1860 * '' Dendrofissurella'' Mclean and Kilburn, 1986 * '' Diodora'' Gray, 1821 * '' Emarginula'' Lamarck, 1801 * '' Fissurella'' Bruguière, 1789 * '' Fissurellidea'' d'Orbigny, 1841 * '' Fissurisepta'' Seguenza, 1863 * '' Hemimarginula'' McLean, 2011 * '' Hemitoma'' Swainson, 1840 * '' Laeviemarginula'' Habe In Kuroda, 1953 * '' Laevinesta'' Pilsbry and McGinty, 1952 * '' Leurolepas'' J. H. McLean, 1970 * '' Lucapina'' Sowerby, 1835 * '' Lucapinella'' Pilsbry, 1890 * '' Macroschisma'' Sowerby, 1839 * '' Manganesepta'' McLean & Geiger, 1998 * '' Medusafissurella'' Mclean and Kilburn, 1986 * '' Megathura'' Pilsbry, 1890 * '' Monodilepas'' Finlay, 1927 * '' Montfortia'' Récluz, 1843 * '' Montfortista'' Iredale, 1929 * '' Montfortula'' Iredale, 1915 * '' Montfortulana'' Habe, 1961 * '' Nesta'' Adams, 1870 * '' Octomarginula'' McLean, 2011 * '' Parmaphorella'' Strebel, 1907 * '' Profundisepta'' McLean & Geiger, 1998 * '' Puncturella'' R. T. Lowe, 1827 * '' Pupillaea'' Gray In Sowerby, 1835 * '' Rimula'' DeFrance, 1827 * '' Rimulanax'' Iredale, 1924 (taxon inquerendum) * '' Scelidotoma'' Choe, Yoon and Habe, 1992 * '' Scutus'' Montfort, 1810 * '' Stromboli'' Berry, 1954 * '' Tugali'' Gray in Dieffenbach, 1843 * '' Tugalina'' Habe, 1953 * '' Vacerrena'' Iredale, 1958 * '' Variemarginula'' McLean, 2011 * '' Zeidora'' A. Adams, 1860 ; Genera brought into synonymy: * ''Austroglyphis'' Cotton & Godfrey, 1934: synonym of ''Diodora'' Gray, 1821 * ''Aviscutum'' Iredale, 1940: synonym of '' Scutus'' Montfort, 1810 * ''Capiluna'' Gray, 1857: synonym of '' Diodora'' Gray, 1821 * ''Cemoria'' Risso, 1826 x Leach MS synonym of '' Puncturella'' Lowe, 1827 * ''Cremoria'' ray, 1842 synonym of '' Puncturella'' Lowe, 1827 * ''Elegidion'' Iredale, 1924: synonym of ''Diodora'' J. E. Gray, 1821 * ''Emarginella'' Pilsbry, 1890: synonym of ''Emarginula'' Lamarck, 1801 * ''Entomella'' Cotton, 1945: synonym of '' Emarginula'' Lamarck, 1801 * ''Fissuridea'' Swainson, 1840: synonym of ''Diodora'' J. E. Gray, 1821 * ''Glyphis'' Carpenter, 1857: synonym of '' Diodora'' J. E. Gray, 1821 * ''Legrandia'' Beddome, 1883: synonym of '' Zeidora'' A. Adams, 1860 * ''Megatebennus'' Pilsbry, 1890: synonym of '' Fissurellidea'' d'Orbigny, 1839 * ''Nannoscutum'' Iredale, 1937: synonym of '' Scutus'' Montfort, 1810 * ''Nesta'' H. Adams, 1870: synonym of '' Zeidora'' A. Adams, 1860 * ''Notomella'' Cotton, 1957: synonym of '' Emarginula'' Lamarck, 1801 * ''Parmophoridea'' Wenz, 1938: synonym of '' Parmaphorella'' Strebel, 1907 * ''Parmophorus'' Blainville, 1817: synonym of '' Scutus'' Montfort, 1810 * ''Plagiorhytis'' P. Fischer, 1885: synonym of '' Montfortula'' Iredale, 1915 * ''Scutum'' P. Fischer, 1885: synonym of '' Scutus'' Montfort, 1810 * ''Semperia'' Crosse, 1867: synonym of '' Emarginula'' Lamarck, 1801 * ''Sipho'' T. Brown, 1827: synonym of '' Puncturella'' Lowe, 1827 * ''Siphonella'' Issel, 1869: synonym of '' Montfortista'' Iredale, 1929 * ''Subemarginula'' Gray, 1847: synonym of '' Hemitoma'' Swainson, 1840 * ''Subzeidora'' Iredale, 1924: synonym of ''Emarginula (Subzeidora)'' Iredale, 1924 * ''Tugalia'' Gray, 1857: synonym of '' Tugali'' Gray, 1843 * ''Vacerra'' Iredale, 1924: synonym of '' Puncturella'' Lowe, 1827 * ''Zidora'' P. Fischer, 1885: synonym of '' Zeidora'' A. Adams, 1860

References

General references

* *

Inline citations

External links

Archerd Shell Collection : Fissurellidae
* * * Aktipis S.W., Boehm E. & Giribet G. (2011) ''Another step towards understanding the slit-limpets (Fissurellidae, Fissurelloidea, Vetigastropoda, Gastropoda): a combined five-gene molecular phylogeny''. Zoologica Scripta 40: 238-259.
Miocene Gastropods and Biostratigraphy of the Kern River Area, California; United States Geological Survey Professional Paper 642
* {{Authority control Taxa named by John Fleming (naturalist) Gastropod families