Pholadidae, known as piddocks or angelwings, are a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

bivalve Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

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 similar to a

clam Clam is a common name for several kinds of bivalve mollusc. The word is often applied only to those that are deemed edible and live as infauna, spending most of their lives halfway buried in the sand of the sea floor or riverbeds. Clams h ...

Background

Piddocks are unique in that each side of their shells is divided into 2 or 3 separate sections. Furthermore, one of the piddock's shells has a set of ridges or "teeth", which they use to grind away at clay or soft rock and create tubular burrows. The shape of these burrows is due to the rotating motion of the piddock as it grinds the rock to make its home. The piddock stays in the burrow it digs for the entirety of its eight-year lifespan, with only its

siphon A siphon (; also spelled syphon) is any of a wide variety of devices that involve the flow of liquids through tubes. In a narrower sense, the word refers particularly to a tube in an inverted "U" shape, which causes a liquid to flow upward, abo ...

exposed to take in water that it

filters Filtration is a physical process that separates solid matter and fluid from a mixture. Filter, filtering, filters or filtration may also refer to: Science and technology Computing * Filter (higher-order function), in functional programming * Fil ...

for food. When the piddock dies and leaves an empty tubular burrow, other marine life such as

sea anemone Sea anemones ( ) are a group of predation, predatory marine invertebrates constituting the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemone ...

, crabs and other molluscs may use the burrow. Some species of Pholadidae may reach up to 18 cm (7″). Their coloration is typically white, though through consumption of

red tide A harmful algal bloom (HAB), or excessive algae growth, sometimes called a red tide in marine environments, is an algal bloom that causes negative impacts to other organisms by production of natural algae-produced toxins, water deoxygenation, ...

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

some may develop a pink coloration. * The Atlantic mud-piddock, ''

Barnea truncata Barnea may refer to: * Barnea is an olive cultivar, see List of olive cultivars There are hundreds of cultivars of the olive (''Olive, Olea europaea''). As one of the oldest and more important domesticated crops raised by humans, the olive tree has ...

'', often referred to as the fallen angelwing, is classed among the angelwing varieties, growing up to 5.7 cm (2¼″) and is similar to other angelwings but with weaker sculpture. One end is squared off and the other end pointed. Loose accessory plates are located above the hinge on live specimens. It possesses a white exterior and interior. It burrows into mud, clay or softwood. Occasionally it is washed onto sounds and ocean beaches, and has a habitat range from

Nova Scotia Nova Scotia is a Provinces and territories of Canada, province of Canada, located on its east coast. It is one of the three Maritime Canada, Maritime provinces and Population of Canada by province and territory, most populous province in Atlan ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

. This fragile shell is rarely dug from mud without breaking. It burrows deeply and has long, united siphons. * The false angelwing '' Petricola pholadiformis'', is also classed among varieties of angelwing, growing up to 7 cm (2¾″). It has a thin, elongate shell resembling a small angelwing but lacks the rolled-out hinge area. Its beak is at one end of the shell with strong radial ribbing on the beak end. Teeth are located on hinge and a deep pallial sinus and partially united siphons. It has a white exterior and interior. It typically burrows into hard surfaces such as clay or peat in intertidal zones. It is commonly found on sounds and ocean beaches with a range from

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

Uruguay Uruguay, officially the Oriental Republic of Uruguay, is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast, while bordering the Río de la Plata to the south and the A ...

. * The common piddock ('' Pholas dactylus'') is known for its

bioluminescence Bioluminescence is the emission of light during a chemiluminescence reaction by living organisms. Bioluminescence occurs in multifarious organisms ranging from marine vertebrates and invertebrates, as well as in some Fungus, fungi, microorgani ...

Vincent Pieribone and David F. Gruber. ''Aglow in the Dark: The Revolutionary Science of Biofluorescence.'' Harvard University Press, 2005. and was investigated by Raphaël Dubois in his 1887 discovery of

luciferin Luciferin () is a generic term for the light-emitting chemical compound, compound found in organisms that generate bioluminescence. Luciferins typically undergo an enzyme-catalyzed reaction with Oxygen, molecular oxygen. The resulting transforma ...

Genera and selected species

* Genus '' Aspidopholas'' P. Fischer, 1887 ** '' Aspidopholas yoshimurai'' Kuroda & Teramachi, 1930 * Genus '' Barnea'' Risso, 1826 ** ''

Barnea candida Barnea may refer to: * Barnea is an olive cultivar, see List of olive cultivars There are hundreds of cultivars of the olive (''Olive, Olea europaea''). As one of the oldest and more important domesticated crops raised by humans, the olive tree has ...

Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

1758 Events January–March * January 1 – Swedish biologist Carl Linnaeus (Carl von Linné) publishes in Stockholm the first volume (''Animalia'') of the 10th edition of ''Systema Naturae'', the starting point of modern zoologic ...

** ''

Barnea davidi ''Barnea davidi'' is a species of marine life, marine bivalve mollusc in the family (biology), family Pholadidae. Distribution ''B. davidi'' is found in the Northwest Pacific, along the shorelines of China (Bohai Sea, Yellow Sea and Zhejiang), ...

'' (Deshayes, 1874) ** ''

Barnea fragilis Barnea may refer to: * Barnea is an olive cultivar, see List of olive cultivars There are hundreds of cultivars of the olive (''Olive, Olea europaea''). As one of the oldest and more important domesticated crops raised by humans, the olive tree has ...

'' (G. B. Sowerby II, 1849) ** ''

Barnea manilensis Barnea may refer to: * Barnea is an olive cultivar, see List of olive cultivars There are hundreds of cultivars of the olive (''Olive, Olea europaea''). As one of the oldest and more important domesticated crops raised by humans, the olive tree has ...

'' (

Philippi Philippi (; , ''Phílippoi'') was a major Greek city northwest of the nearby island, Thasos. Its original name was Crenides (, ''Krēnĩdes'' "Fountains") after its establishment by Thasian colonists in 360/359 BC. The city was renamed by Phili ...

, 1847) ** '' Barnea parva'' Pennant, 1777 ** '' Barnea similis'' (Gray, 1835) ** '' Barnea subtruncata'' (G. B. Sowerby I, 1834) ** ''

'' ( Say, 1822) * Genus '' Chaceia'' Turner, 1855 ** '' Chaceia ovoidea'' (Gould, 1851) * Genus '' Cyrtopleura'' Tryon, 1862 ** '' Cyrtopleura costata'' (

) * Genus '' Diplothyra'' Tryon, 1862 ** '' Diplothyra smithii'' Tryon, 1862 * Genus '' Jouannetia'' Desmoulins, 1828 ** '' Jouannetia quillingi'' Turner, 1955 * Genus '' Lignopholas'' R. D. Turner, 1955 ** '' Lignopholas rivicola'' (G. B. Sowerby II, 1849) * Genus '' Martesia'' G. B. Sowerby I, 1824 ** '' Martesia cuneiformis'' ( Say, 1822) ** '' Martesia fragilis'' A. E. Verrill and Bush, 1890 ** '' Martesia striata'' (

) * Genus '' Netastoma''

Carpenter Carpentry is a skilled trade and a craft in which the primary work performed is the cutting, shaping and installation of building materials during the construction of buildings, ships, timber bridges, concrete formwork, etc. Carpenter ...

, 1864 ** '' Netastoma darwinii'' (Sowerby, 1849) ** '' Netastoma japonicum'' (Yokoyama, 1920) ** '' Netastoma rostratum'' (

Valenciennes Valenciennes (, also , , ; ; or ; ) is a communes of France, commune in the Nord (French department), Nord Departments of France, department, Hauts-de-France, France. It lies on the Scheldt () river. Although the city and region experienced ...

, 1846) * Genus '' Nipponopholas'' Okamoto & Habe, 1987 ** '' Nipponopholas satoi'' Okamoto & Habe, 1987 * Genus '' Parapholas'' Conrad, 1848 ** '' Parapholas californica'' (Conrad, 1837) * Genus '' Penitella''

, 1846 ** '' Penitella conradi''

, 1846 ** '' Penitella fitchi'' Turner, 1955 ** '' Penitella gabbii'' (Tryon, 1863) ** '' Penitella hopkinsi'' Kennedy and Armentrout, 1989 ** '' Penitella kamakurensis'' (Yokoyama, 1922) ** '' Penitella penita'' (

Conrad Conrad may refer to: People * Conrad (name) * Saint Conrad (disambiguation) Places United States * Conrad, Illinois, an unincorporated community * Conrad, Iowa, a city * Conrad, Montana, a city * Conrad Glacier, Washington Elsewher ...

, 1837) ** '' Penitella richardsoni'' Kennedy, 1989 ** '' Penitella turnerae'' Evans and Fisher, 1966 * Genus ''

Pholadidea ''Pholadidea'' is a taxonomic genus of marine (ocean), marine bivalve molluscs in the subfamily Martesiinae of the family Pholadidae (the piddocks). Most members of ''Pholididea'' bore into shale, soft rock and coral for shelter, with the except ...

'' Turton, 1819 ** '' Pholadidea acherontea'' Beu and Climo, 1974 ** ''

Pholadidea loscombiana ''Pholadidea'' is a taxonomic genus of marine (ocean), marine bivalve molluscs in the subfamily Martesiinae of the family Pholadidae (the piddocks). Most members of ''Pholididea'' bore into shale, soft rock and coral for shelter, with the except ...

'' Turton, 1819 ** '' Pholadidea spathulata'' (Sowerby, 1850) ** '' Pholadidea tridens'' (Gray, 1843) * Genus '' Pholas''

** '' Pholas campechiensis''

Gmelin Gmelin may refer to: * Karl Christian Gmelin, Carl Christian Gmelin (1762–1837), German botanist, author of ''Flora Badensis, Alsatica et confinium regionum cis- et transrhenania'' (1806) * Charles Gmelin (1872–1950), British Olympic athlete * ...

, 1791 ** '' Pholas dactylus''

– common piddock ** '' Pholas orientalis''

, 1791 * Genus '' Talona'' Gray, 1842 ** '' Talona explanata'' (Spengler, 1792) * Genus '' Zirfaea'' Gray, 1842 ** '' Zirfaea crispata'' (

) ** '' Zirfaea pilsbryi'' Lowe, 1931

Gallery

Image:Piddocks 01 (pfly).jpg, Siphons of the rough piddock, '' Zirfaea pilsbryi'' in

Puget Sound Puget Sound ( ; ) is a complex estuary, estuarine system of interconnected Marine habitat, marine waterways and basins located on the northwest coast of the U.S. state of Washington (state), Washington. As a part of the Salish Sea, the sound ...

Image:Pholades niches.jpg, burrows, 2.5 cm (1″) or less, in calcic rock, coast Boulogne - Calais (France) Image:Angelwing burrow1.jpg, Angelwing and associated burrows

References

External links

Angelwing

NC Sea Grant ''Seashells of NC Field Guide''

Angelwing, ''Cyrtopleura costata''

ITIS

{{Authority control Bivalve families Taxa named by Jean-Baptiste Lamarck

Background

Genera and selected species

Gallery

See also

References

External links