Didemnum

Didemnum
Tunicate colonies of Didemnum
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Tunicata
Class:	Ascidiacea
Order:	Aplousobranchia
Family:	Didemnidae
Genus:	Didemnum Savigny, 1816

Didemnum is a genus of tunicates in the family Didemnidae. Some species of Didemnum can be characterized as invasive species. This is particularly an issue off the east coast of the United States, where in early 2006, Didemnum were estimated to inhabit more than 175 square kilometers of this undersea region. Other areas where Didemnum are seen as invasive include Canada, New Zealand and the Netherlands.

Didemnum vexillum turned up on coast of state of Washington in 2009 and showing up in Coos Bay and Winchester Bay, Oregon as of 13 May 2010.

Species

• Didemnum albidum (Verrill, 1871)
• Didemnum amethysteum (Van Name, 1902)
• Didemnum asperum (Milne-Edwards, 1841)
• Didemnum biglans (Sluiter, 1906)
• Didemnum candidum Savigny, 1816
• Didemnum carnulentum Ritter and Forsyth, 1917
• Didemnum chilense Arnbaeck, 1929
• Didemnum coriaceum (Von Drasche, 1883)
• Didemnum fulgens (Milne-Edwards, 1841)
• Didemnum galacteum Lotufo & Dias, 2007
• Didemnum gelatinosum
• Didemnum helgolandicum
• Didemnum lahillei Hartmeyer, 1909
• Didemnum maculosum (Milne-Edwards, 1841)
• Didemnum santaelenae Van Name, 1945
• Didemnum studeri Hartmeyer, 1911
• Didemnum tenue (Herdman, 1886)
• Didemnum vanderhorsti Van Name, 1924
• Didemnum vexillum Kott, 2002

Tunicate colonies of Didemnum sp. overgrowing the fronds of dark green algae. These colonies can quickly overgrow most surfaces and other organisms.

References

• Woods Hole
• (USGS) National Geologic Studies of Benthic Habitats, Northeastern United States has a Marine Nuisance Species page dedicated to this genus

External links

• Species Profile- Sea Squirt (Didemnum vexillum), National Invasive Species Information Center, United States National Agricultural Library. Lists general information and resources for Sea Squirt.