The windowpane oyster (''Placuna placenta'') is a

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of marine and freshwater Mollusca, molluscs that have laterally compressed bodies enclosed by a shell consisting of two hing ...

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the family of Placunidae. They are edible, but valued more for their shells (and the rather small pearls). The shells have been used for thousands of years as a glass substitute because of their durability and translucence. More recently, they have been used in the manufacture of decorative items such as chandeliers and lampshades; in this use, the shell is known as capiz shell (''kapis'')."Fisheries and aquaculture of window-pane shells"
Malacological Society of London. Retrieved on 2011-10-23. Capiz shells are also used as raw materials for glue, chalk and varnish. Distribution extends from the shallows of the

Gulf of Aden The Gulf of Aden ( ar, خليج عدن, so, Gacanka Cadmeed 𐒅𐒖𐒐𐒕𐒌 𐒋𐒖𐒆𐒗𐒒) is a deepwater gulf of the Indian Ocean between Yemen to the north, the Arabian Sea to the east, Djibouti to the west, and the Guardafui Chann ...

to around the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

, where it is abundant in the eponymous province of

Capiz Capiz, officially the Province of Capiz (Capiznon/ Hiligaynon: ''Kapuoran sang Capiz''; tl, Lalawigan ng Capiz), is a province in the Philippines located in the central section of Western Visayas region. Its capital is the city of Roxas. It ...

. The mollusks are found in muddy or sandy shores, in bays, coves and lagoons to a depth of about . Populations have been in decline because of destructive methods of fishing and gathering such as

trawling Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch different spec ...

dredging Dredging is the excavation of material from a water environment. Possible reasons for dredging include improving existing water features; reshaping land and water features to alter drainage, navigability, and commercial use; constructing d ...

, blast fishing and

surface-supplied diving Surface-supplied diving is diving using equipment supplied with breathing gas using a diver's umbilical from the surface, either from the shore or from a diving support vessel, sometimes indirectly via a diving bell. This is different from sc ...

. In the Philippines, fisheries are now regulated through permits, quotas, size limits and protected habitats. In spite of this, resources continue to be depleted. The nearly flat shells of the capiz can grow to over in diameter, reaching maturity between . The shell is secured by a V-shaped

ligament A ligament is the fibrous connective tissue that connects bones to other bones. It is also known as ''articular ligament'', ''articular larua'', ''fibrous ligament'', or ''true ligament''. Other ligaments in the body include the: * Peritoneal l ...

. Males and females are distinguished by the color of the

gonad A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sp ...

Fertilization Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Pro ...

is external and

larvae A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. T ...

are free-swimming like plankton for 14 days or attached to surfaces via byssal thread during

metamorphosis Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ...

, eventually settling on the bottom. tp://ftp.fao.org/docrep/fao/009/w7191e/w7191e19.pdf "Bivalves" Retrieved on 2011-10-24. They consume

plankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a cruc ...

filtered from the water passing through their slightly opened shell; the shell closes if the bivalve is above water during low tide.

The capiz industry of Samal, Philippines

Aside from being abundant in the province of Capiz, capiz shells are also abundant in the island of Samal in the Philippines, where 500 tons of capiz shells are harvested every other year. The capiz shells found around the island are harvested and transformed into various decorative products. As late as 2005, the residents of the island were trained to sustain the industry. However, the transfer of institutional knowledge to new generations to maintain the industry is not being maintained and is in danger of being lost. File:12. Natividad Morente Dela Joya Ancestral House, Pinamalayan 05.JPG, Capiz shell windows are an important icon in Philippine culture File:Simple capiz parol.jpg, A

parol A parol (, , also written as paról or parul, from Spanish ''farol'', meaning ''lantern'') is a Filipino ornamental lantern displayed during the Christmas season. Parols are traditionally constructed using bamboo and Japanese paper, and are ...

made with capiz shells for its panes File:MuseoSanPablojf7215 06.JPG, A decorative mobile at the Museo de San Pablo in

San Pablo, Laguna San Pablo, officially the City of San Pablo ( fil, Lungsod ng San Pablo), is a 1st class component city in the province of Laguna, Philippines. According to the 2020 census, it has a population of 285,348 people. It is located in the souther ...

, Philippines using capiz shells. File:Calasiao Church convent -- window.JPG, Traditional windows with sliding panes made with capiz shells at the convent of

Calasiao Church The Saints Peter and Paul Parish Church (''Iglesia Parroquial de los Santos Pedro y Pablo''), commonly known as Calasiao Church is a baroque church located in Poblacion West, Calasiao, Pangasinan, Philippines. It belongs to the Vicariate of Sts. ...

in the

References

{{Commons category Placunidae Commercial molluscs Molluscs described in 1758 Taxa named by Carl Linnaeus Oysters Edible molluscs Philippine handicrafts

The capiz industry of Samal, Philippines

See also

References