Phlebobranchia is an order of tunicate in the class Ascidiacea,[Gittenberger, A.; Sanamyan, K. (2015). Phlebobranchia. In: Shenkar, N.; Gittenberger, A.; Lambert, G.; Rius, M.; Moreira Da Rocha, R.; Swalla, B.J.; Turon, X. (2015) Ascidiacea World Database. Accessed through: World Register of Marine Species on 2015-12-23] first described by Fernando Lahille in 1886.[Lahille, F. (1886). Sur le classification des Tuniciers. C.R. Acad. Sci. Paris. 16: 1573-1575]
Characteristics
The group includes both colonial and solitary animals. They are distinguished from other sea squirts by the presence of longitudinal vessels in the pharyngeal basket. This provides the etymology of their name: in
ancient greek, φλέψς, φλεβός means "blood vessel". Another characteristic of phlebobranchians is the
being surrounded by a loop of gut. The posterior part of the abdomen is absent, and many species also lack the epicardial cavity that surrounds the heart and other internal organs in many other sea squirts.
Taxonomy
Image:Red spotted sea squirt at Castle Rocks P7260863.JPG| Ascidia incrassata (Ascidiidae)
Image:CionaintestinalisR.jpg| Ciona intestinalis (Cionidae)
Image:Megalodicopia Okeanos.jpg| Megalodicopia sp. (Octacnemidae)
Image:Perophora namei (Phlebobranch).jpg| Perophora namei (Perophoridae)
