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Craspedacusta sowerbii

Craspedacusta sowerbii
Craspedacusta sowerbyi by OpenCage.jpg
Scientific classification
Kingdom: Animalia
Phylum: Cnidaria
Class: Hydrozoa
Order: Limnomedusae
Family: Olindiidae
Genus: Craspedacusta
Species: C. sowerbii
Binomial name
Craspedacusta sowerbii
Lankester, 1880
Synonyms

Craspedacusta sowerbyi (lapsus)


Craspedacusta sowerbyi (lapsus)

Craspedacusta sowerbiiis is a freshwater jellyfish in the phylum Cnidaria. Since it is classified as a hydrozoan, it is one of many jellyfish that are also known as hydromedusae. Hydromedusan jellyfish differ from scyphozoan jellyfish because they have a muscular, shelf-like structure called a velum on the ventral surface, attached to the bell margin. Originally from the Yangtze basin in China, C. sowerbii is an invasive species now found throughout the world in bodies of fresh water.

C. sowerbii medusae are about 20–25 mm (approximately 1 in.) in diameter, somewhat flatter than a hemisphere, and very delicate, when fully grown. They have a whorl of up to 400 tentacles tightly packed around the bell margin. Hanging down from the center of the inside of the bell is a large stomach structure called a manubrium, with a mouth-opening with four frilly lips. Circulation of nutrients is facilitated by four radial canals which originate at the edges of the stomach (manubrium), and which are also connected to a ring canal, located near the bell margin. Most of the body is transparent or translucent, with a whitish or greenish tinge. The (usually) four large flat sex organs (gonads) are attached to the four radial canals, and are usually opaque white. The many tentacles each contain thousands of cells called cnidocytes, which contain (also known as cnidocysts), and are used to capture prey and pass it to the mouth. Food is taken in the mouth opening, and waste is finally expelled out of the same opening.

C. sowerbii is native to the Yangtze basin in China, but has been introduced widely around the world (the only continent where not found is Antarctica). It is usually found in calm, freshwater reservoirs, lakes, impoundments, gravel pits or quarries. They have also been seen in slow-moving backwaters of river systems such as the Allegheny River, the Ohio River and the Tennessee River in the United States and the Wang Thong River of Thailand. They prefer standing water, and are not generally seen in fast flowing streams or rivers.


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Wikipedia

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