''Pteria penguin'', commonly known as the penguin's wing oyster, is a species of marine

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 ...

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

in the

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 ...

Pteriidae Pteriidae, also called the feather oysters, is a family (biology), family of medium-sized to large saltwater oysters. They are pearl oysters, Marine (ocean), marine bivalve mollusks in the order Pteriida. Some of the species in this family are i ...

, the pearl oysters. It is native to the western and central

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

region and is used for the production of

cultured pearl Cultured pearls are pearls which are formed within a cultured pearl sac with human intervention in the interior of productive living molluscs in a variety of conditions depending upon the mollusc and the goals. Having the same material as natur ...

s. The generic name comes from Greek πτερον (pteron) meaning wing.

Distribution and habitat

''Pteria penguin'' is native to the western and central Indo-Pacific region. Its range extends from the East African coast and the Red Sea to India, southern China, southern Japan, the Philippines, Indonesia and northern Australia. It is found attached by its byssal threads to a number of different substrates, rocks and corals (especially to Gorgonacea), at intertidal depths of less than .Sealife Base
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Description

''Pteria penguin'' can reach a common shell length of about , with a maximum length of . The shells of this rather large species are solid and ovate. The posterior ear develops a narrow, elongated, wing-like expansion. The left valve is more inflated than the right one. The outside color of the shell ranges from dark brown to black, while the interior is nacreous silvery, a wide non-nacreous glossy black margin

Biology

As well as most of the species of the class

Bivalvia 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 ...

, these ''wing oysters'' are

gonochoric In biology, gonochorism is a sexual system where there are two sexes and each individual organism is either male or female. The term gonochorism is usually applied in animal species, the vast majority of which are gonochoric. Gonochorism contrast ...

. Embryos of this species at first develop into a free-swimming planktonic marine larva, then followed by a

veliger A veliger is the planktonic larva of many kinds of sea snails and freshwater snails, as well as most bivalve molluscs (clams) and tusk shells. Description The veliger is the characteristic larva of the gastropod, bivalve and scaphopod taxono ...

, quite similar to a small clam.

Pearl culture

Wild oysters of this species seldom contain pearls. When they do, they tend to be irregular in shape and have the same range of pinkish hues that are typical of the

nacre Nacre ( , ), also known as mother-of-pearl, is an organicinorganic composite material produced by some molluscs as an inner shell layer. It is also the material of which pearls are composed. It is strong, resilient, and iridescent. Nacre is ...

lining the shells. The maximum diameter of the pearls is about . Because the shell valves of this species are so thin, it was beyond the competence of nineteenth century oyster culturists to use it for pearl production. With modern techniques, seeding has become easier and ''Pteria penguin'' has joined '' Pteria sterna'', another member of the genus '' Pteria'', as being a major producer of cultured pearls. Most of the pearls produced by ''Pteria penguin'' are "mabé pearls", also known as bubble or half pearls, formed between the mantle and the shell valve and having one flattened side. The production of round pearls is possible but requires more advanced techniques in seeding. Naturally occurring spat can be collected on spat collectors for growing on into mature oysters, and there are some hatcheries producing spat on a commercial scale. These oysters are cultured on the

Ryukyu Islands The , also known as the or the , are a chain of Japanese islands that stretch southwest from Kyushu to Geography of Taiwan, Taiwan: the Ryukyu Islands are divided into the Satsunan Islands (Ōsumi Islands, Ōsumi, Tokara Islands, Tokara and A ...

, along the southern coast of China, on

Phuket Island Phuket (; , , or ''Tongkah'') is one of the southern provinces (''changwat'') of Thailand. It consists of the island of Phuket, the country's largest island, and another 32 smaller islands off its coast. Phuket lies off the west coast of m ...

in Thailand and on Vava'u in Tonga.

Gallery

File: Pteria penguin 01 by Line1.JPG , Intetrior valve with pearls File: Naturalis Biodiversity Center - RMNH.MOL.318322 - Pteria penguin (Röding, 1798) - Pteriidae - Mollusc shell.jpeg, Museum specimens File: Pteria penguin Maldives.JPG, Two specimens live

References

{{Taxonbar, from=Q10884808 Pteriidae Bivalves described in 1798