Venerupis philippinarum
Encyclopedia
Venerupis philippinarum is an edible species
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 saltwater clam
Clam
The word "clam" can be applied to freshwater mussels, and other freshwater bivalves, as well as marine bivalves.In the United States, "clam" can be used in several different ways: one, as a general term covering all bivalve molluscs...

, a marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...

 bivalve mollusk in the family Veneridae
Veneridae
The Veneridae or venerids, also known as the Venus clams, are a very large family of minute to large, saltwater clams, marine bivalve molluscs. There are over 500 living species of venerid bivalves, most of which are edible, and many of which are exploited as a food source.Many of the most...

, the Venus clams.

The common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...

s of the species include "Japanese littleneck", "Manila clam", "steamer clam", "Filipino Venus", "Japanese cockle", and "Japanese carpet shell".

Description

The shell of Venerupis philippinarum is elongate, oval, and sculptured with radiating ribs (Morris, 1980). It grows to 7.5 cm (3 in) across and 3.5 cm (1.4 in) in width. The color is highly variable: it is commonly grayish, greenish, brownish, yellow or buff with distinct dark or light colored, with triangular mottled markings that begin at the umbo
Umbo
Umbo may refer to:*A shield boss* umbo , at the top of some mushrooms*The Umbo of tympanic membrane - a part of the human body*Umbo is the part of a Bivalve shell which was formed when the animal was a juvenile...

 and disperse outwards. The true color can be distorted by dark gray staining, caused by anoxic mud. The foot of live specimens is an orange color.

The features most diagnostic for the identification of this species are the following: that the inner ventral margin of the shell is smooth; the ligament is prominent and elevated above the dorsal margin. In the living animal, the siphons are separated at the tips (Carlton, 2007). Water is drawn in and out of a clam by siphons that protrude from the posterior end of the shell. In this species, the siphons are mostly fused, and are only separate at the tips. The siphons are short relative to some other clams, which means that the clam lives burrowed only a shallow distance under the surface of the substrate. Short siphons are what inspire the common name “littleneck clam”.

Possible misidentifications

In western North America, this species is often confused with Protothaca staminea
Protothaca staminea
Protothaca staminea, or the Pacific littleneck clam, is a species of bivalve mollusc in the family Veneridae. This species of mollusc was exploited by early humans in North America; for example, Chumash peoples of Central California harvested this creature from Morro Bay approximately 1000 years...

, however, V. philippinarum shells are more elongate than P. staminea. Internally, V. philippinarum has yellowish valves, with a purple suffusion near the posterior margin. Protothaca staminea lacks this purple suffusion. This species may be found together with Protothaca staminea, but tends to reside at slightly higher tide levels.

Habitat

This species is native from southern Siberia
Siberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...

 to China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

. It was introduced to the West Coast
West Coast of the United States
West Coast or Pacific Coast are terms for the westernmost coastal states of the United States. The term most often refers to the states of California, Oregon, and Washington. Although not part of the contiguous United States, Alaska and Hawaii do border the Pacific Ocean but can't be included in...

 of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 with oyster spat from Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 and now occurs from the British Columbia Coast
British Columbia Coast
The British Columbia Coast or BC Coast is Canada's western continental coastline on the Pacific Ocean. The usage is synonymous with the term West Coast of Canada....

  to the Central Coast of California
Central Coast of California
The Central Coast is an area of California, United States, roughly spanning the area between the Monterey Bay and Point Conception. It extends through Santa Cruz County, San Benito County, Monterey County, San Luis Obispo County, and Santa Barbara County...

. It lives from the mid to low intertidal zone
Intertidal zone
The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...

 in bay
Bay
A bay is an area of water mostly surrounded by land. Bays generally have calmer waters than the surrounding sea, due to the surrounding land blocking some waves and often reducing winds. Bays also exist as an inlet in a lake or pond. A large bay may be called a gulf, a sea, a sound, or a bight...

s and estuaries
Estuary
An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....

, in mud, sandy mud and cobble, buried 2 centimetre below the surface.

Life history

V. philippinarum breeds in the summer. Larvae then continue to grow slowly (especially in areas of crowding), reaching maturity at 1 centimetre , and will live from 7–10 years. A non-native species, V. philippinarum was introduced during the 1930s, brought over from Japan with oyster spat from Japanese oysters. It is now extremely common amongst the Pacific coast, and is highly prized for food (Morris, 1980). V. philippinarum is also capable of withstanding salinities as low as 30-50 percent of that of pure seawater
Seawater
Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% . This means that every kilogram of seawater has approximately of dissolved salts . The average density of seawater at the ocean surface is 1.025 g/ml...

, and can tolerate levels of high pollution.

Predators

Predators include moon snails (Euspira lewisii
Euspira lewisii
Euspira lewisii , common name Lewis' moon snail, is a species of large operculated sea snail. It is a predatory marine gastropod in the family Naticidae, the moon snails....

), the Atlantic oyster drill (Urosalpinx cinerea
Urosalpinx cinerea
Urosalpinx cinerea, common name the eastern or Atlantic oyster drill, is a species of small predatory sea snail, a marine gastropod mollusk in the family Muricidae, the murexes or rock snails....

), Dungeness crab (Cancer magister), red rock crab (Cancer productus
Cancer productus
Cancer productus, one of several species known as the red rock crab, is a crab of the genus Cancer found on the western coast of North America.- Description :...

), bat rays (Mylobatus californicus), flounder
Flounder
The flounder is an ocean-dwelling flatfish species that is found in coastal lagoons and estuaries of the Northern Atlantic and Pacific Oceans.-Taxonomy:There are a number of geographical and taxonomical species to which flounder belong.*Western Atlantic...

, sturgeon
Sturgeon
Sturgeon is the common name used for some 26 species of fish in the family Acipenseridae, including the genera Acipenser, Huso, Scaphirhynchus and Pseudoscaphirhynchus. The term includes over 20 species commonly referred to as sturgeon and several closely related species that have distinct common...

, willet (Catoptrophorus semipalmatus), ring billed gulls (Larus delawarensis) and raccoons (Procyon lotor) among others.

External links

  • Venerupis philippinarum from the Invertebrate Zoology and Evolution wiki (Spring 2008) at Evergreen State College
  • Venerupis philippinarum from San Francisco Estuary Institute's Guide to the Exotic Species of San Francisco Bay
    San Francisco Bay
    San Francisco Bay is a shallow, productive estuary through which water draining from approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean...

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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